theothermy

NGO Greenpeace claimed that most of our existing infrastructure was actually a big menace as far as climate change goes. It claimed that eight of the nine buildings it surveyed at random in Delhi and Mumbai were guilty of energy wastage due to leakages on account of faulty design, use of inadequate insulating material and non-maintenance.

In a first of its kind exercise, these buildings were selected randomly for a thermographic test wherein their images were taken with a special infrared camera that was claimed to have captured the excessive energy leakage in them. The buildings included Mumbai Stock Exchange building in the financial capital and National Stock Exchange building, American Center and a five star hotel in Delhi. Officials of American Centre refused to comment on the exercise. A majority of buildings in our cities would meet the same fate.

Only the ITC building in Gurgaon could pass muster and was awarded the ‘Green Building’ tag.

K.Srinivas, climate and energy expert, Greenpeace India, said: “Our probe into the building sector in India has yielded startling results. Energy efficiency in the first important step to address India’s energy crisis and fight climate change. Our energy consumption can be halved by smart use of energy. The photos we have taken are indicative of the electricity wastage that a cross-section of our climate buildings are responsible for as well as the requirement for mandatory efficiency in the building sector.”

Thermography is a technology that shows temperature difference on the building surface area. A uniform temperature difference on the building surface means an environment friendly building. Temperature variations on the surface indicate that the cool air from inside the building is allowed to escape, implying that more energy is required to maintain the temperature inside the building.

In the past five years, the use of air-conditioning in India has been growing at the rate of almost 50% each year, according to figures made available by Greenpeace. Electricity consumption for air-conditioning in residential buildings has been about 7-10%, with a growth rate of consumption in the range of 15-20% per annum. Reduction in the leakage of cool air from buildings has the potential to reduce electricity consumption by over 40%.

According to a recent Inter-Governmental Panel on Climate Change report, the building sector also has a high level of electricity usage and hence the total emissions from this sector are very high. The report also states that energy efficiency in new and existing buildings in India can reduce carbon dioxide emissions by about 30% by 2030. The bureau of energy efficiency came out with a building efficiency code for new buildings in India in May 2007. However, compliance with the code is voluntary at present.

Deeksha Chopra

Times of India, 28th June,2007 Read more on this article...

The Pope condemns the climate change prophets of doom
By SIMON CALDWELL
12th December 2007
Pope Benedict XVI has launched a surprise attack on climate change prophets of doom, warning them that any solutions to global warming must be based on firm evidence and not on dubious ideology.

The leader of more than a billion Roman Catholics suggested that fears over man-made emissions melting the ice caps and causing a wave of unprecedented disasters were nothing more than scare-mongering.

The German-born Pontiff said that while some concerns may be valid it was vital that the international community based its policies on science rather than the dogma of the environmentalist movement.

His remarks will be made in his annual message for World Peace Day on January 1, but they were released as delegates from all over the world convened on the Indonesian holiday island of Bali for UN climate change talks.

The 80-year-old Pope said the world needed to care for the environment but not to the point where the welfare of animals and plants was given a greater priority than that of mankind.


Adrift: Polar bears on melting iceberg.

"Humanity today is rightly concerned about the ecological balance of tomorrow," he said in the message entitled "The Human Family, A Community of Peace".

"It is important for assessments in this regard to be carried out prudently, in dialogue with experts and people of wisdom, uninhibited by ideological pressure to draw hasty conclusions, and above all with the aim of reaching agreement on a model of sustainable development capable of ensuring the well-being of all while respecting environmental balances.

"If the protection of the environment involves costs, they should be justly distributed, taking due account of the different levels of development of various countries and the need for solidarity with future generations.

"Prudence does not mean failing to accept responsibilities and postponing decisions; it means being committed to making joint decisions after pondering responsibly the road to be taken."

Efforts to protect the environment should seek "agreement on a model of sustainable development capable of ensuring the well-being of all while respecting environmental balances", the Pope said.

He added that to further the cause of world peace it was sensible for nations to "choose the path of dialogue rather than the path of unilateral decisions" in how to cooperate responsibly on conserving the planet.

The Pope's message is traditionally sent to heads of government and international organisations.

His remarks reveal that while the Pope acknowledges that problems may be associated with unbridled development and climate change, he believes the case against global warming to be over-hyped.

A broad consensus is developing among the world's scientific community over the evils of climate change.

But there is also an intransigent body of scientific opinion which continues to insist that industrial emissions are not to blame for the phenomenon.

Such scientists point out that fluctuations in the earth's temperature are normal and can often be caused by waves of heat generated by the sun. Other critics of environmentalism have compared the movement to a burgeoning industry in its own right.

In the spring, the Vatican hosted a conference on climate change that was welcomed by environmentalists.

But senior cardinals close to the Vatican have since expressed doubts about a movement which has been likened by critics to be just as dogmatic in its assumptions as any religion.

In October, the Australian Cardinal George Pell, the Archbishop of Sydney, caused an outcry when he noted that the atmospheric temperature of Mars had risen by 0.5 degrees celsius.

"The industrial-military complex up on Mars can't be blamed for that," he said in a criticism of Australian scientists who had claimed that carbon emissions would force temperatures on earth to rise by almost five degrees by 2070 unless drastic solutions were enforced.

End of Post
Read more on this article...

"Calculation of the heat loss through twin skin or composite panel metal construction brings
particular difficulties. Simplified methods are possible in some cases, but 2- or 3-dimensional
heat flow calculations must be carried out for some U-value and for all thermal bridge calculations. A number of software packages are available but many important decisions, which have a very significant effect on the results, are left to the user."

"Some standards, including BS EN 1252414, and the BRE U-values Conventions7 quote a conventional value of 50 W/mK for the conductivity of steel. The available information suggests that 60 W/mK is a more appropriate value for metal cladding systems. That value was used in the preparation of MCRMA Technical Note 143 and has been assumed in this guide."

The following steps are necessary to find the U-value,  (Omega)-value or f-value:

Details to be included in the model
a) Spacers – Section 5.1
b) Cladding rails - Section 5.3
c) Air cavities – Section 5.4
d) Profiles – Section 5.5
e) Fasteners - Section 5.6
f) Size of the model - Section 5.10

http://www.mcrma.co.uk/pdf/mcrma_t18.pdf

End of Post Read more on this article...

"Albedo includes the visible, infrared and ultraviolet wavelengths on a scale of 0 to 1. An albedo value of 0.0 indicates that the surface absorbs all solar radiation, and a 1.0 albedo value represents total reflectivity. EPA ENERGY STAR specifies an albedo of 0.65 or higher for low-slope roof applications and 0.25 for sloped roofs."

"Most roofing industry experts agree that a cool roof is one the exhibits a combination of high reflectivity and high emissivity."

"LEED version 2.2, released in October 2005, is the first national specification to use a relatively new measure of reporting a cool roof's properties. LEED 2.2 sustainable site credit 7.2 states that to receive one point, building owners should use a roof with a Solar Reflective Index (SRI) of 78 over at least 75% of the roof surface for roofs with slopes less than 2:12. The new twist is SRI, a unit developed by scientists at Lawrence Berkeley National Laboratory. SRI incorporates reflectivity and emissivity properties into one, easy to read, standardized measure so that roof buyers won't have to scratch their heads and try to figure our if a high reflectivity and low emissivity is better or worse than a medium reflectivity and high emissivity."

"SRI is calculated with a complex formula spelled out in ASTM E1980 and is a scale of 1 to 100 that is a measure of a roof's combined thermal properties. It is defined so that a standard black (reflectance 0.05, emittance 0.90) is 0 and a standard white (reflectance 0.80, emittance 0.90) is 100. But some hot roofs can have negative values, and some white thermoplastics and white roof coatings have scored as high as 104 to 100."

"SRI as a method for reporting cool roof data will probably take a little while to catch on. The Cool Roof Rating Council, an organization that verifies and labels cool roofing products has begun using the measure, while retaining reflectivity and emissivity measurements."

"The albedo of an object is the extent to which it diffusely reflects light, defined as the ratio of diffusely reflected to incident electromagnetic radiation. It is a unitless measure indicative of a surface's or body's diffuse reflectivity. The word is derived from Latin albedo "whiteness, in turn from albus "white".

"The term albedo (Latin for white) is commonly used to applied to the overall average reflection coefficient of an object. For example, the albedo of the Earth is 0.39 (Kaufmann) and this affects the equilibrium temperature of the Earth. The greenhouse effect, by trapping infrared radiation, can lower the albedo of the earth and cause global warming."

"The albedo of an object will determine its visual brightness when viewed with reflected light. "

"In more technical treatments of albedo, such as that of de Pater and Lissauer, a distinction is made between "bond albedo" and "geometric albedo", the numbers quoted above being geometric albedos. The geometric albedo is defined as the amount of radiation relative to that from a flat Lambertian surface which is an ideal reflector at all wavelengths. The bond albedo is the total radiation reflected from an object compared to the total incident radiation from the Sun. The bond albedo for the Earth is given as 0.29 by de Pater and Lissauer, compared to their value of 0.37 for the geometrical albedo."

ECBC U-value adjustment:

Cool Roofs:

"Roofs with slopes less than 20 degrees shall have an initial solar reflectance of no less than 0.70 and an initial emittance no less than 0.75. Solar reflectance shall be determined in accordance with ASTM E903-96 and emittance shall be determined in accordance with ASTM E408-71 (RA 1996)."

There seems to be no adjustment to the U value for a high albedo surface, unlike that available in some countries.

"The Roof/Ceiling U-value for buildings that are mechanically cooled and have a roof covering with a high-albedo surface can be increased in accordance with this section provided the roof surface:

a) has a minimum total solar reflectance of 0.75 when tested in accordance with ASTM E 903, and

b) has a minimum infrared emittance of 0.75 when tested in accordance with ASTM E408."

Ref: http://eetd.lbl.gov/coolroof/

For databases on properties of cool roof materials. Read more on this article...

(This may need a little mulling over!)

Orientation - The baseline (standard) building performance shall be generated by simulating the building with its actual orientation and again after rotating the entire building 90, 180, 270 degrees, then averaging the results. The building shall be modeled so that it does not shade itself.

Fenestration — Fenestration areas shall equal that in the proposed design or 40% of gross above grade wall area, whichever is smaller, and shall be distributed uniformly in horizontal bands across the four orientations. No shading projections are to be modeled; fenestration shall be assumed to be flush with the exterior wall or roof. Manually operated fenestration shading devices such as blinds or shades shall not be modeled.

Roof albedo - All roof surfaces shall be modeled with a reflectivity of 0.30

Ref: http://hareda.gov.in/ECBC.PDF (ECBC 2006)

End of Post Read more on this article...

Reference: http://www.indiaworldenergy.org/brochure/ECBC.pdf

Quote:

"Most commercial buildings have (an) Energy Performance Index (EPI) of 200 to 400 kWhr/sqm/year in India."

"The average energy use for a typical commercial building is 200 kwh/square metre/year. Mandatory enforcement of the ECBC can reduce this to 120-160 kwh/sqm a year (a saving of 30-40 per cent)."

--

A typical office building: (Gurgaon)

Base EPI: = 186 kWhr/sqm/annum

After envelope optimisation: 165 kWhr/sqm/annum
After lighting optimisation: 120 kWr/sqm/annum
After HVAC optimisation: 98 kWhr/sqm/annum
After HVAC controls: 92 kWhr/sqm/annum
After daylight integration: 86 kWhr/sqm/annum

Therefore;
Reduction over base building due to envelope: = 11.3% (186-165)/186
Reduction over base building due to lighting: = 24.2% (165-120)/186
Reduction over base building due to HVAC: = 13.3% (120-98)/186
Reduction over base building due to HVAC controls: = 3.2% (98-92)/186
Reduction over base building due to Daylighting: = 3,2% (92-86)/186

That would mean a reduction in HVAC of 11.3% + 13.3% + 3.2% = 27.8%

and that for lighting; 24.2% + 3.2% = 27.4%

Total savings on account of HVAC and lighting alone: 27.8% + 27.4% = 55.2%.

--

Personal opinion:

That does seem rather high. Maybe that's because the base building itself had a thin wall, uninsulated roof, and extensive single glazing poorly oriented in the first place.

Considering the fact that around 57% of the energy in a typical Indian building is consumed by the HVAC system, and 16% by the lighting, seems that the envelope optimisation (which finally contributes to the HVAC load) could have been further optimised.

Afterthought:

Or, the equipment load was very high :)

End of Post Read more on this article...

A great wiki on Sun-Path diagrams from Square-1. Has animated gifs.

http://squ1.org/wiki/Sun_Path_Diagram

End of Post Read more on this article...

Courtesy:

http://www.learn.londonmet.ac.uk/packages/clear/interactive/analyser/index.html

Click the link for the interactive two-paned windows.

"The Design Matrix seeks to put the various elements of the building into context and aims to show how they can play a part in producing a successful design solution. A matrix of available solutions is provided with thumbnail sketches as a guide to the context. This matrix is backed by notes which give more detailed information and guidance in each area of concern.

The Performance Analyser allows the user to compare the impact of five different building 'elements' on indoor temperature and energy use:

* Thermal mass
* insulation
* window size
* window orientation
* window shading

Results are presented in the context of five different climates:

* London (cool)
* Athens (Mediterranian)
* Delhi (composite)
* Ahmedabad (desert)
* Trivandrum (hot-humid)

In each climate there are three alternative outputs:

* temperatures and comfort for an average summer day (choice a)
* a hot summer day (choice b)
* monthly energy use for heating and/or cooling (choice c)

Results are presented in two side-by-side windows so that the outputs from two different options can be directly compared. For details of the assumptions behind the simulations used in the Analyser please press the 'Parameters' button."

End of Post Read more on this article...

Courtesy: http://www.analemma.com

"The difference in time between what your watch reads and the position of the sun (clock time vs. sun time) is called the Equation-of-Time. If you are in the northern hemisphere and the sun’s position is to the east of where your watch indicates it would be, the Equation-of-Time is negative. If the sun is to the west, the Equation-of-Time is positive.

There is an easier way to see this effect. Find a place where the sun shines on the ground at noon all year long - winter, spring, summer, and fall. Place a rod about 3 feet tall into the ground, being very careful not to bump the end of it during the year. If you were constructing a sundial, this rod would be called a gnomon.

On the first day of each month, at the same time every day, (subtracting one hour if you are observing daylight saving time) place a mark with another shorter rod (you will need 12 of these) where the sun makes a shadow with the tip of the longer original rod. At the end of 12 months, you will see that the short rods make a figure-8 pattern on the ground.

Why does the sun take this strange path? There are two reasons and they are completely independent from each other.

1. The Earth is tilted on its axis 23.5° in relation to the plane of its orbit around the sun.

2. The Earth does not orbit the sun in a circle, but in an ellipse.

It is simply the sum of these two effects that causes the analemma.

It is hoped that with the aid of a few diagrams and animations, the analemma can be readily understood. "

---



Anthony Ayiomamitis of Greece, has the most beautiful images of the Analemma.

http://www.perseus.gr/Astro-Solar-Analemma.htm

"Strange as it may seem, only seven times has someone ever managed to successfully image the solar analemma as a multi-exposure on a single piece of film. For those not familiar with the term, an analemma is the figure "8" loop that results when one observes the position of the sun at the same time during the day over the course of a year. Due to the earth's tilt about its axis (23.45°) and its elliptical orbit about the sun, the location of the sun is not constant from day to day when observed at the same time on each day over the course of a full year. Furthermore, this loop will be inclined at different angles depending on one's geographical latitude.

Since the analemma is considered one of the most difficult and demanding astronomical phenomenon to image, I immediately set out on such a marathon during the summer of 2001 by pursuing a complete set of analemmas from 08:00:00 to 17:00:00 UT+2 (hourly intervals) as well as the special case of the perfectly vertical analemma on the meridian (12:28:16 UT+2)." Read more on this article...

Click to enlarge Read more on this article...

Composite (Delhi)
Hot Dry (Ahmadabad)
Hot Humid (Kolkata),
Moderate (Bangalore)
Cold (Shillong)

Click to enlarge. End of Post Read more on this article...

Extract from:

http://www.glassmagazine.net/articles.php?id=724

“Are all the technical specifications in the ECBC to the satisfaction of the glass industry? Maybe not,” says Satish Kumar, chief of party for India’s energy conservation program, International Resource Group, New Delhi. “However, instead of getting stuck on a number for SHGC [solar heat gain coefficient] and visual transmittance that will be acceptable to the industry, it should be realized that inclusion of aggressive technical specifications is an indication of the will of the government to make changes quickly. ECBC is likely to be in a voluntary mode for the next two to three years, which gives the glazing industry enough time to start gearing up for the mandatory phase of the ECBC.”

“The Commonwealth Games will be hosted in India in 2010 in New Delhi, and more than 400 new hotels will be built, along with several buildings to host the participants,” says Bipin Shah, international coordinator, National Fenestration Rating Council, Silver Spring, Md. “Due to low commercial building stock, there is a shortage of commercial space in New Delhi. Rents are five times than that in Washington D.C.”

However, like any other project, the code implementation comes with its share of problems. Padmanaban lists them: “Lack of trained professionals required to design compliant buildings; perception of increased first cost and delays that a project will have to face in order to be compliant with the ECBC; lack of availability of energy-efficient equipment and materials in the local marketplace; lack of equipment testing and certification; and institutional barriers in enforcing any codes.”

To overcome the issues, the USAID India is working with International Resources Group and its partners to implement an energy efficiency commercialization project, titled ECO 3. “We’ve been working with two, three states,” says Archana Walia, program management specialist, USAID India. “We’ll be developing an implementation plan for the chosen state, and it will need approval from the minister of power,” says Kumar, who is the chief of party of the USAID ECO3 Program.

The Center for Environmental Planning and Technology University in Ahmedabad, Gujarat, has been chosen to house the center of excellence. “The Center for Sustainable Environment and Energy in CEPT University will aim to integrate building design with energy-efficient practices, and bring the engineers, architects and designers up to speed with the latest technology for energy efficiency in buildings through training and workshops,” Shah says.

The land for the center will be provided by CEPT University and the fund for the building is expected to come from the state government. The All India Flat Glass Manufacturers’ Association will provide Rs. 2.5 crores, about $560,000, to buy the machines, Shah says. Sintex Industries, near Ahmedabad, a manufacturer of PVC doors, windows and modular furniture in India, has declared Rs. 1 crore support for CEPT University to start the energy center. This money is expected to be provided over the next five years. Karnataka already has such a center of excellence, Walia says.


http://www.glassmagazine.net/articles.php?id=724 Read more on this article...

http://en.wikipedia.org/wiki/Image:India_wind_zone_map_en.svg

(SVG file, nominally 1639 × 1852 pixels, file size: 349 KB). Click to enlarge.

End of Post
Read more on this article...

The ones who scream and shout, are the ones who intend to profit the most. That, in a few words, is the economical history of mankind.

End Of Post Read more on this article...

NUSA DUA, Indonesia (AFP) - A drama-filled 190-nation conference on Saturday set a 2009 deadline for a landmark pact to fight global warming after an isolated United States backed down on last-ditch objections.

UN Secretary General Ban Ki-moon hailed the so-called Bali Roadmap as a "pivotal first step" towards a new agreement for tackling the peril of climate change, after he had appealed to delegates to show flexibility.

Following gruelling all-night talks the conference launched a process to negotiate a new treaty that will take effect when the UN Kyoto Protocol's commitments expire in 2012.

The deal comes after a year of stark warnings from Nobel-winning scientists, who say that millions of people will be at risk of hunger, homelessness and disease by 2100 if temperatures keep rising at current rates.

The United States, the only major industrial nation to reject the Kyoto treaty, reached a compromise with the European Union (EU) to avoid mentioning any figures as a target for slashing greenhouse gas emissions.

The agreement instead only makes an indirect reference to scientists' warnings that the world must sharply cut back emissions to prevent what could be a catastrophic rise in temperatures.

But on an unscheduled 13th day of talks, the United States said it would not accept the statement as it wanted developing countries such as fast-growing China to make tougher commitments.

Senior US negotiator Paula Dobriansky said she had heard "many strong statements from many major developing country leaders on a greater role in helping to address urgently this global problem."

It "doesn't seem it's going to be reflected in our outcome here in the declaration," she said, telling the conference that the United States would reject the draft.

Dobriansky was loudly booed by other delegations. A US environmental activist representing Papua New Guinea said on the floor to rousing cheers: "If you're not willing to lead, please get out of the way."

After repeated verbal lashings, Dobriansky again took the microphone and said that Washington would "go forward and join consensus," to the cheers of the conference.

German Environment Minister Sigmar Gabriel, an outspoken critic of President George W. Bush's climate policy, said he was ready to ask through his mobile telephone for Chancellor Angela Merkel to intervene with the White House.

"I had already typed the SMS after Dobriansky's first statement but then I was able to cancel it," Gabriel said.

"In the end, nobody wanted to have a failure," including the United States, Gabriel said. "We have achieved more than we could have expected previously, but it is less than what is needed to meet the urgency of the problem."

The agreement came after extraordinary scenes in which the head of the United Nations jetted in to make a last-ditch appeal, the UN's exhausted climate chief nearly broke down in tears and chairman Indonesia apologised abjectly for a disastrous procedural mix-up.

"The Bali Roadmap that has been agreed is a pivotal first step toward an agreement that can address the threat of climate change, the defining challenge of our time," a statement from the UN chief said.

Alden Meyer of the US-based Union of Concerned Scientists welcomed the deal.

"What we witnessed today was an incredible drama," he said "I've been following these negotiations for 20 years and I've never seen anything like it."

Hans Verolme of conservation group WWF accused the world of bowing to US pressure and removing a scientific punch needed to fight global warming.

But he also said the Bali talks would inspire environmentalists and activist nations for climate-change negotiations until the end of President George W. Bush's mandate in January 2009.

"We have learned a historic lesson. If you expose to the world the dealings of the United States, they will ultimately back down," he said.

As activists speculated on whether the US U-turn was premeditated, US delegates said they believed from the reaction to their initial statement that developed countries would be serious about climate change.

"There is no question that we have opened a new phase in moving forward together," said senior White House aide James Connaughton. "The time had come to start a new chapter."

Bush has argued that the Kyoto Protocol is unfair as it does not require fast-growing emerging economies such as China, the second largest emitter after the United States, to meet targeted emissions curbs.

In a bid to break the deadlock, the proposed document ditched European calls for an "ambition" of the rich world to cut its emissions by 25 to 40 percent by 2020 from 1990 levels.

And there was no mention of a target of halving global levels of greenhouse gases by 2050 -- a goal that scientists say is essential to limiting the warming to around two degrees Celsius (3.6 degrees Fahrenheit).

http://news.yahoo.com/s/afp/20071215/wl_asia_afp/unclimatewarming_071215103717

End of Post Read more on this article...

40% don't give a damn.

End of Post Read more on this article...

Hourly Load Calculation Analysis Programme for Indian Cities

Vikram Murthy and Rajeev Kakkar, ISHRAE Mumbai Chapter

Rajeev Kakkar is a Technical Consultant (HVAC) by profession, a graduate from I.I.T Kharagpur, and has over 30 years of experience in the field. He is also the webmaster for http://www.hvacindia.com, the Technical advisor for the "Hourly Load Calculation Programme" sponsored by ISHRAE, and faculty for IIE, the "ISHRAE Institute Of Excellence" training programme series conducted by ISHRAE Mumbai Chapter.

Vikram Murthy graduated from IIT Kanpur in Electrical enginering in 1975 . He is Director of Univac Environment Systems Private Limited and Trustee of Tropical Airconditioning and Refrigeration Institute , a recognised Training Centre, for Technicians and Engineers. He has 33 years of diverse experience in leading HVAC Contracting Companies , is active professionally and socially , serving ISHRAE as the President of the Mumbai Chapter for 2007 - 2008 and The Rotary Club of Bombay Film City since 1992.


Abstract:

The ability to make sensible decisions regarding the HVAC design with respect to environment and economics is of utmost importance. Air-conditioning load calculations in India have been carried out using single day peak load manual calculations. The commercially available tools for load calculations are either too simple to be used for professional work (low-end packages) or too expensive with long and difficult learning curves. In a recently concluded research project, ISHRAE and ASHRAE India Chapter have developed a database of the hourly values of climatic parameters. The next step obviously was to develop an Hourly Load Calculation Programme.

Key words: hourly load calculation programme; HLCP; cooling loads; EnergyPlus; ECBC; building energy simulation; hourly weather data


Preamble:

Considering the fact that there is an urgent requirement of a validated HVAC sizing programme which uses BIS Design Day Standards and also provides hourly outputs using the heat balance equations found in EnergyPlus (and as adapted from BLAST), the development of HLCP as an ISHRAE project has been timely. The ability to make sensible and well-based decisions regarding not only the prediction of energy consumption in a building during the conceptual and design stage, but also to be able to finally size the HVAC system, both with respect to environment and economics, is of utmost importance.


Current Methodologies:

Currently, HVAC sizing loads is carried out mainly by manual and spreadsheet methods based on the de-facto standard of calculating instantaneous heat gains using methods developed by Carrier, and based on tabulated empirical ETDs (Effective Temperature Differences) for fenestration, walls and roofs, apart from a myriad of programmes developed by individuals, which have not really been validated. The current methodology also adopts use of design day weather data based on simultaneous peak occurrences of DB temperature and WB temperature, and whose validity and source is not known and has been lost in antiquity.


Weather Data:

In 1999 the Tata Energy Research Institute (TERI), http://www.teriin.org/ developed a set of hourly Indian weather data sets for 52 stations from measured sequences of climatic data from 1981 to 1992 based on the concept of "coincident" temperatures in line with and in the format as published in the ASHRAE Handbook of Fundamentals, 1997. With the availability of WeDCo hourly and DesignDay weather data, and with the virtually simultaneous availability of a stable version of the EnergyPlus simulation engine, an opportunity arose to create a cooling load programme using WeDCo weather data as an input to EnergyPlus.

As EnergyPlus is more of a "black box" with a shell for input, which is more suitable for research rather than day-today sizing calculations, it was logical to propose and deliver a HVAC sizing programme with a GUI to serve the needs of the community in India.


Interfaces and tools:

The commercially available tools so far for energy analysis and load calculations were either too simple to be used for professional work (low-end packages) or too expensive with long and difficult learning curves (high-end packages).


HLCP, hourly Load Calculation Programme:

HLCP is simplified zone-by-zone method for calculation of HVAC cooling loads for sizing of equipment specifically for Commercial buildings, based only on numerical inputs. HLCP uses the "Purchased Air" system type in EnergyPlus which is itself implemented based on the ASHRAE cooling sizing method and the cooling design load calculations are carried out using the standard ASHRAE Heat Balance method. That solves the issue of validation. HLCP is not just a graphical user interface for the EnergyPlus simulation engine; rather, it's an interface to calculate hourly loads. Post-processing of the data also takes care of the hourly latent loads. The user interface has been kept free of icons, with tabs and buttons in plain English, so that even the average HVAC engineer is able to use HLCP after a few trail runs. The interface has been designed as a tabbed wizard, again for ease of use, without unnecessary clutter of providing options which may really not be relevant for an HVAC sizing exercise.

HLCP can do what manual or spreadsheet HVAC sizing programmes cannot. That puts HLCP right in the path of the ECBC. In all likelihood, energy simulation interfaces built over EnergyPlus, such as DesignBuilder will be prominently used for compliance with the ECB code, during the Feasibility and Site Planning phase, and the Outline Design Phase of the building. During this stage, it would be necessary for the building to comply with the ECB code, and at this stage the Architect would have a much greater say than the HVAC designer. As the building design moves to the Scheme Design and from there to the Detailed Design, it is the HVAC engineer who will most likely call the shots.


ECBC and HLCP:

On 27th May 2007, The Bureau of Energy Efficiency, India, BEE, released the Energy Conservation Building Codes ECBC, for Commercial Buildings. One of the clauses in the ECBC (apart from the clauses which specify the U values for walls, roofs and fenestrations), is that "The equipment capacities for the standard design shall be sized proportionally to the capacities in the proposed design based on sizing runs; i.e., the ratio between the capacities used in the annual simulations and the capacities determined by the sizing runs shall be the same for both the proposed design and standard design. Unmet load hours for the proposed design shall not differ from unmet load hours for the standard design by more than 50 hours."


Conclusion:

This really means that it would be a wise step to compare the energy simulation loads with the design loads in parallel, as the building design moves from the feasibility and site planning stage to the detailed design stage, so as to ensure that this requirement of the ECBC is met without any ambiguity. The use of a building energy simulation programme in conjunction with HLCP, using the same weather data and the same simulation engine, in this case, EnergyPlus, would ensure compliance.

Further Information on HLCP can be found at: http://hvacindia.com/hlcp/


References:

[1] ASHRAE Handbook of Fundamentals 1997

[2] Proceedings of the 23rd National Renewable Energy Convention, pp. 284-289,
edited by R L Sawhney, D Buddhi, and R P Gautam. Indore: Devi Ahilya
Vishwavidyalaya.
Extract: http://static.teriin.org/division/eetdiv/reta/docs/abs12.htm

[3] Review of Inside Design Conditions in Air Conditioned Spaces, by N. S. Hukmani, The
Air Conditioning and Refrigeration Journal, January 2004.
http://www.hvacindia.com/journals_20042005/2004jan/article05.html

[4] Weather Data & Design Conditions For India,
booklet published by ISHRAE and AIC

[5] InputOutputReference.pdf, 2007
EnergyPlus documentation.

[6] Carrier Systems Design Manual

[7] Weather data - ISHRAE
http://www.eere.energy.gov/buildings/energyplus/cfm/weather_data3.cfm/
region=2_asiawmo_region_2/country=IND/cname=India

[8] EnergyPlus: The Merger of BLAST and DOE-2, 1998 - Dru Crawley
http://eetd.lbl.gov/newsletter/CBS_NL/nl18/energyplus.html

[9] What outside Design Conditions should I use in calculating a heat load?

[10] ECBC 2007
Read more on this article...

Key sentence:

"Run it again"

End of Post
Read more on this article...

Or maybe, HLCP has landed on the Eagle!

"Indian Interface to EnergyPlus: HLCP Hourly Load Calculation Program HLCP (Hourly Load Calculation Programme) is a graphical user interface for design-day and hourly load calculations for Indian cities, meant to be used with the EnergyPlus simulation engine. HLCP is a for-purchase program. For details, please go to http://www.hvacindia.com/hlcp/ "

http://gundog.lbl.gov/dirun/28nov.pdf

End of Post

Read more on this article...

WINDOW 5.2 is a publicly available computer program for calculating total window thermal performance indices (i.e. U-values, solar heat gain coefficients, shading coefficients, and visible transmittances). WINDOW 5.2 provides a versatile heat transfer analysis method consistent with the updated rating procedure developed by the National Fenestration Rating Council (NFRC) that is consistent with the ISO 15099 standard. The program can be used to design and develop new products, to assist educators in teaching heat transfer through windows, and to help public officials in developing building energy codes.

http://windows.lbl.gov/software/window/window.html

THERM is a module of the WINDOW+5 program under development by LBNL. WINDOW+5 is the next generation of the WINDOW software series and is being developed for the Microsoft Windows™ operating environment. THERM's results can be used with WINDOW's center-of-glass optical and thermal models to determine total window product U-factors and Solar Heat Gain Coefficients.

THERM is a state-of-the-art, Microsoft Windows™-based computer program developed at Lawrence Berkeley National Laboratory (LBNL) for use by building component manufacturers, engineers, educators, students, architects, and others interested in heat transfer. Using THERM, you can model two-dimensional heat-transfer effects in building components such as windows, walls, foundations, roofs, and doors; appliances; and other products where thermal bridges are of concern.

http://windows.lbl.gov/software/therm/therm.html
End of Post Read more on this article...

Time Magazine has named the San Francisco Federal Building one of its 2007 "Best Inventions of the Year" winners in the architecture category. Its citation noted that the building is "really a machine for delivering sunlight and fresh air to the people who work there." EnergyPlus was used to model the building's energy efficiency features. End of Post Read more on this article...

We have all heard of Willis Haviland Carrier as the engineer and inventor, and who is known as the man who invented modern air conditioning. At the age of 25, he devised his first important invention, a system to control heat and humidity for the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, and was eventually made the head of the Buffalo Forge subsidiary named Carrier Air Conditioning Company in his honor.

Not many may have heard of Gintautas “Gint” Povilas Mitalas.


Photo courtesy IBPSANews

Gint was born in Lithuania in April 1928. In 1953 he went to the University of Toronto to study mechanical engineering, graduating with a BASc in 1957 and an MSc in 1959. Gint joined the staff of the National Research Council of Canada in 1959 to work in the Division of Building Research, where he was part of a small group that was exploring ways to improve the accuracy of the calculation of heat transfer through walls. In the early 1960s he used an analog computer to simulate the heat flow through walls and roofs. Later he shifted his effort to using digital computers for calculating heat gain through walls and roofs. This led to the Response Factor approach, and finally to the Z -Transfer Function method that was adopted by ASHRAE. He became a member of ASHRAE in 1966.

Gint presented two papers at the highly successful “First international symposium on the use of computers for environmental engineering related to buildings” that was held in Washington, DC in 1970.

IBPSA makes awards for outstanding work in the building performance simulation field. It was first awarded in 1991 to Gint Mitalas for his outstanding service and lifetime accomplishments in building simulation.

He passed away in Ottawa, Canada on 13 May 2005.

Gint shall be remembered for his pioneering work on energy simulation which has lead to the current revolution in whole building energy simulation software.
End of Post Read more on this article...

With the release of EnergyPlus 2.1, there's been a very interesting announcement in connection with Google SketchUp and the weather data convertor, which now produces KML output for Google Earth.

A beta version of building simulation within SketchUp is planned n the next few weeks. In the first release in early 2008, users will be able to draw their building, paint the surfaces with thermophysical properties, select default building type information, schedules, and HVAC systems, and simulate the energy performance of their building — all within SketchUp.

WeatherConverter now produces KML output (for Google Earth) of latitude, longitude, elevation, and a few climate statistics for locations in a list processing run.

Several other interfaces are under development—including two from China and India. These are likely to be announced shortly on; http://www.energyplus.gov/ep_interfaces.html

EnergyPlus V 2.1 is now available at no cost from the EnergyPlus web site http://www.energyplus.gov
End of Post Read more on this article...

As part of a project announced Tuesday, the Internet search leader and its philanthropic arm will pour hundreds of millions of dollars into a quest to lower the cost of producing electricity from renewable energy sources such as wind and the sun.

If Google realizes its goal, the cost of solar power should fall by 25 to 50 percent, co-founder Larry Page said in an interview.

"If we achieve these goals, we are going to be in the (electricity) business in a very big way," Page said. "We should be able to make a lot of money from this."

http://www.tech2.com/india/news/general/google-expands-into-alternative-energy/
22785/0?utm_source=dailynewsletter&utm_medium=email

End of Post
Read more on this article...

EnergyPlus "Most Wanted!"

http://gundog.lbl.gov/dirpubs/wanted.pdf

HLCP "Young Turks!"

http://picasaweb.google.com/hlcp.support/HLCPTeam

End of Post Read more on this article...

Update:

It is done!!

Name: HLCP - Hourly Load Calculation Programme
Date of Birth (DD/MM/YYYY)
22/11/2007
Time of Birth (24Hrs Format)
4:39:0
Place of Birth
Mumbai,Maharashtra,India
Latitude (Degree/min/(North/South))
018/58/N
Longitude (Degree/min/(East/West))
072/50/E
Time Zone
5.5
DST Correction
0
Moon sign: Pisces

And I'll be ready to ship HLCP!! The last bug has been captured, the screens are clean, the colours are bright again, and the software is well obfuscated. :)End of Post Read more on this article...

Ellen Brown, November 5th, 2007

Excerpt:
"During the recent bank credit crisis in August 2007, the central banks of the United States, Europe, Canada, Australia and Japan collectively extended a $315 billion credit line to commercial banks. This credit was created out of nothing – something central banks assume the right to do as "lenders of last resort" – and the sums advanced were huge.6 For comparative purposes, a mere $188 billion would have been enough to repair all of the 74,000 U.S. bridges known to be defective, preventing another disaster like that in Minnesota in July 2007. The Carbon Trust, a well-known UK company dedicated to cutting carbon emissions, is responsible for reducing emissions by nearly 2 million tons per year on a 2007 budget of only £115.9 million (about $240 million U.S.). If central banks can create hundreds of billions of dollars to save floundering private banks, governments can create comparable credits to adapt to climate change, an even more pressing problem."

Read more

http://www.webofdebt.com/articles/energy-costs.php Read more on this article...

A short demo of a GUI for EnergyPlus developed by Gurneet Singh.

http://cbs.iiit.net/resume/2002batch/gurneet/cad/demo/EnergyGSdemo.html

End of Post Read more on this article...

Update: The final HLCP Help file dated 20th November 2007 has been uploaded to www.hvacindia.com/hlcp/


Finally, a detailed 74 page Help file in pdf format (1.6 mB) uploaded for download to:

http://hvacindia.com/hlcp/

Screen animations coming soon. First copies of HLCP, the Hourly Load Calculation Programme (using the EnergyPlus engine), developed by ISHRAE to be shipped on Teusday, the 20th of November 2007. End of Post Read more on this article...

By Christopher Booker and Richard North

"Mann's hockey stick was just what the IPCC wanted. When its 2001 report came out it was given pride of place at the top of page 1. The Mediaeval Warming, the Little Ice Age, the 20th century Little Cooling, when CO2 had already been rising, all had been wiped away.

But then a growing number of academics began to raise doubts about Mann and his graph. This culminated in 2003 with a devastating study by two Canadians showing how Mann had not only ignored most of the evidence before him but had used an algorithm that would produce a hockey stick graph whatever evidence was fed into the computer. When this was removed, the graph re-emerged just as it had looked before, showing the Middle Ages as hotter than today.

It is hard to recall any scientific thesis ever being so comprehensively discredited as the "hockey stick". Yet the global warming juggernaut rolled on regardless, now led by the European Union. In 2004, thanks to a highly dubious deal between the EU and Putin's Russia, stage four of the story began when the Kyoto treaty was finally ratified."

"If global warming does turn out to have been a scare like all the others, it will certainly represent as great a collective flight from reality as history has ever recorded. The evidence of the next 10 years will be very interesting." End of Post

http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2007/11/04/eaclimate104.xml
Read more on this article...

Last year I replaced all the windows in my house with that expensive double-pane energy efficient kind, and then today, I got a call from the contractor who installed them. He was complaining that the work had been completed a whole year ago and I still hadn't paid for them. Hellloooo,...........just because I'm blonde doesn't mean that I am automatically stupid. So, I told him just what his fast talking sales guy had told me last year, that in ONE YEAR these windows would pay for themselves! Helllooooo? It's been a year! I told him. There was only silence at the other end of the line, so I finally just hung up. He never called back. Guess I won that stupid argument. I bet he felt like an idiot. End of Post Read more on this article...

India: be the party pooper (Editorial)
By Sunita Narain

US President George Bush played host to a party of the top polluters of
the world called to discuss climate change. He exhorted his guests that
the world needed to act and called for a "new approach" to reduce
emissions. But if you think that he has changed his mind about the
science which has established the reality and urgency of climate change,
think again. Or if you think he has changed his position that his
country will not take on commitments to cut emissions because the
American lifestyle is not open to negotiation, think yet again and again.



The Bush meeting was strategic: first, it was an attempt (and a
successful one) to club the rich countries, who have been old and big
polluters, with the emerging countries-China and India. The meeting was
to remove the difference between the two categories-those who need to
make deep cuts in their emissions and those who need the space to grow.
If the Indians (and the Chinese) were looking for a place at this high
table of polluters, they certainly got their wish.

There is nothing new about Bush's position on climate change. In fact, I
would go so far as to say that there is nothing different about his
position from that of the previous Democratic government led by Bill
Clinton and Al Gore.

This is nothing more than recent history repeating itself. It is
predictable and it is dangerous for the climate and for our common future.

What Bush did should not surprise us. The US has been steadfast: it will
take action (whatever that means) only when it includes all big
polluters, including China and India.

I remember clearly the events in Kyoto in 1997, when the emissions
treaty was being finalised to set legally binding targets on
industrialized countries. That week all the stops were pulled out. The
phones buzzed between the White House and the prime minister's office.

The US made it clear that it wanted "meaningful participation" from
India and China. Its intransigence meant that all other governments
(those of the European Union to Japan) had to work hard to play
matchmaker to get the Chinese and Indians to bend so the US could sign
up to the treaty.

But what the Indian government did by accepting the Bush party invite
now should surprise us. I do accept that its position also remained
steadfast at the recent meeting. It did inform its host that the world
needed to act on the basis of historical contributions to the stock of
greenhouse gas emissions in the atmosphere. And that India's per capita
emissions are negligible compared to those of the flatulent US or the
developed European countries. But believe me when I say this is nothing
other than posturing: rhetoric without any substance.

The fact is that we have agreed tacitly to join the membership of the
polluters-only club. In this way we have blurred (if not altogether
removed) the distinction-followed in all global agreements-between
countries which need to take action first and those who need the
ecological space to grow. But this is just one part of a much bigger
problem.

We have also asserted our right to development without insisting that
the US should take on deep and obligatory emission targets, for all our
sake. We have agreed to this ultimate marriage of convenience-not to ask
the us to commit so that we can get off the hook. We will all take on
"aspirational" targets, Bush said at the meeting. Let us understand this.

This is the ultimate and deadly bribe to seduce India and China: we will
not allow the Europeans and others to push us into legally binding
targets. This way is better: voluntary commitments and no targets.

Just think. This is a way in which we will all go to hell together. The
fact is that the world needs to act. It needs to act decisively and
urgently. We can already see the repercussions of a mere 0.7°c increase
in global temperatures in terms of melting glaciers and extreme weather
and rain events. Just think what it will be like when the world sees, on
average, an increase of 1.5°c, which is now inevitable because of the
stock of emissions already in the atmosphere, or 2°c, which is the best
we can get if we are responsible. The Bush way is disastrous. It must
not be acceptable.

But we are hypocrites. We laid the foundation stone for this Bush
conclave when we agreed to join the Asia-Pacific Partnership on Clean
Development and Climate, which was launched by the US administration
just under two years ago. This partnership had just one aim: to break
the multilateral processes built around legally binding commitments by
proving that voluntary action agreed by the major polluting nations
would be effective. Many meetings down the line, the partnership has led
to nothing concrete on the ground. But then who cares?

But we have to care. Climate is too serious a business to be made a joke
out of, as is done by the US president and his administration. We need
to explain to the rich world why it needs to act decisively and cut its
emissions and how it needs to change its lifestyle. We need to show how
we can participate meaningfully in a strategy to avoid future emissions.

We also need to say how this can be done through providing emission
rights for all; effective technology transfer and hard funds to pay for
transition into low-carbon growth options.

We must make it clear that we are not unwilling and reluctant partners
in this climate endgame. We are players and we are serious. Bush's party
is not ours to enjoy.

Read editorial online >>
http://www.downtoearth.org.in/cover_nl.asp?mode=2

To comment, write to >> editor[AT]downtoearth[DOT]org[DOT]in

Read more on this article...

The goal of Simupedia is to provide qualified information about building simulation to different stakeholders of the built environment, with focus on energy consumption, thermal comfort, room airflow, daylighting and environmental impact. Based on practise in design of real buildings Simupedia shows that building simulations - as a new, innovative approach in the planning process - are superior to the standard way of planning. End of Post. Read more on this article...

Dr. Vishal Garg of the International Institute of Information Technology in Hyderbad, India, has created an EnergyPlus tutorial aimed at architects and engineers who are familiar with the basic concepts of energy simulation and HVAC systems. The tutorial out-lines the procedures for modeling a small room using EnergyPlus, including instruction on how to run the simulation, and how to interpret the output files. The output presents both heating and cooling energy consumption so the user may experiment with size, orientation, material properties, location, etc., and compare heating/cooling energy usage. End of Post. Read more on this article...

Geolus Search - a 3D geometry search engine with real benefits
If you know two parts are similar a world of possibilities opens.

Check it out here. (Registration required). End of Post Read more on this article...

The weather data in use earlier, was not the "coincident" data. As an example, for any outside design Dry Bulb temperature, the corresponding Wet Bulb temperature was no the Wet Bulb temperature occurring simultaneously at that Dry Bulb temperature. In all probability, it was also a maximum Wet Bulb temperature for the particular season in question.

For years, Indian HVAC engineers have been using legacy weather data for Indian cities whose origins are not known. In 1999, the Indian Society of Heating, Refrigerating and Air-Conditioning Engineers (ISHRAE) http://www.ishrae.org.in, in association with Tata Energy Research Institute (TERI) http://www.teriin.org/ , developed a set of Indian weather data, based on the concept of "coincident" temperatures, in line with and in the format as published in the ASHRAE 1997 Fundamentals Handbook.

The set of weather data was created in TMY2 format, a commonly used format in the industry, and was developed for use in Building hourly load, and Building energy simulation programmes.

In 2004 the weather data set was converted to the EPW format as is used by EnergyPlus, an energy simulation engine, and uploaded to and made available to EnergyPlus users.

The "mean coincident Wet Bulb temperature", on the other hand, means the wet bulb temperature occurring at that particular dry bulb temperature, and in that particular 5 degree F interval.

For the first time, the research carried out by ISHRAE and TERI provided users with the "coincident" temperatures.

In addition, the design weather data was classified into three categories, viz; 2%, 1% and 0.4%. annual frequency of occurrance.

The design values represent the value that is exceeded on average by the indicated percentage of the total number of hours in a year (8,760). In other words, the 0.4%, 1.0%, and 2.0% values are exceeded 35-, 88-, and 175-hrs per year respectively.

The weather data for a particular city, at 2% annual frequency of occurance means that for 2% of the hours in a year, (i.e., (2/100) * 24 * 365 = 175 hours), the temperature will be above the temperature in question for 175 hours in a year. (A year has 8760 hours).

For example, for the city of Mumbai, the legacy Summer outside design conditions being considered so far have been 95 deg F and 83 deg F. Compare this with the 2% Dry bulb temperature, and Mean coincident wet bulb temperature from the new weather data, which is 92.3 deg F and 75.2 deg F, figures which are considerably lower than the legacy data.

It is also understood that the air-conditioning system would now be designed such that it was likely that for around 2% of the days in a year, the outside conditions would be higgher than the design conditions. This is acceptable practice for comfort air-conditioning and could result ni considerable savings in initial equipment costs and running loads.

If slightly more stringent conditionas are desired, then the 1% values could be considerd, and for very stringent industrial applications, the 0.4% values could be considered.

While earlier, outside design conditions were provided under the sub-heads of "Summer" "Monsoon" and "Winter", these sub-heads do not exist in the new classification based on annual occurances. Instead for calculating instantaneous space loads for Summer outside conditions, one would usually use the Cooling DB temperature / Mean coincident WB temperature while in Monsoon one would use the Cooling WB temperature / Mean Coincident DB temperature. (For Winter one would use the Heating Db temperature / Mean coincident Wet bulb temperature.

Merely following the above over-simplified rule blindly, however, could lead to serious errors in design.

Consider the situation for a 100% outside air application, (or for a treated air application, or even for an application where the outside air ventilation loads are high):

Assuming that the design is being carried out for the city of Mumbai, we list out the enthalpies of air for both the outside design conditons under investigation.


Design Conditions Comparison

City: Mumbai
Annual frequency of occurance: 2%

Design DB with Mean Coincident WB Design WB with Mean Coincident DB



In the first case for Design DB and mean coincident WB, the enthalpy of the outside air is 38.53 Btu/lb, and would be exceeded for a period of 175 hours as explained earlier.

In the second case for Design WB and mean coincident DB, the enthalpy of the outside air would exceed for a far greater number of hours than in the first case.

Had the outside design conditions been selected as the DB temperature and mean coincident WB temperature, there would have been serious under-sizing of the equipment and the systemw would have been pushed to its limits for a far greater number of hours.

Rajeev Kakkar
Read more on this article...

Ted has a very interesting podcast on R-22 and related refrigerants, and selecting a new refrigerant for home use and general climate change topics.

http://mediacloud.libsyn.com/tedg332/CI5.mp3

You can near more of Ted's wonderfully modulated podcasts at :

Carbon issues podcasts

End of Post Read more on this article...

R-22 (HCFC-22) is the most widespread refrigerant being used in India for room air-conditioners, split air-conditioners, packaged air-conditioners and reciprocating central plant systems. R-22 (HCFC-22) is currently also being used in a large proportion of positive displacement compressor based chillers and in some larger tonnage centrifugal chillers. These uses predate the Montreal Protocol, but will be phased out as part of the overall HCFC phase-out. In the U.S., HCFC-22 cannot be used in new equipment after Jan 1, 2010.

So what's so special or different in the new refrigerants, such as R-407C and R-410A that make them different from the user-friendly R-22?

R-22 is a HCFC, i.e, a Hydro-Chloro-Flouro-Carbon, that contains chlorine, and which when released in the atmosphere, causes ozone, O3 to be converted to O2, and thereby depletes the Ozone layer.

However, R-22 has zero potential to increase global warming.

R407C is one of the HFC blends that is intended for HCFC-22 replacement, but it is zeotropic and not suited for use in a flooded evaporator. R-407C has been used in reciprocating chillers with direct expansion evaporators.

R-407C Contains R-32, R-125 and R-134a (23/25/52 by weight in %).

The use of substitute refrigerants such as R407C and 410A, while having zero potential to deplete the Ozone layer, create a new set of issues which must be understood. The following sections explain these issues in layman's terms:

The Ozone Depletion Potential
The Global Warming Potential
Zeotropes and Non-Zeotropes
The lubricating oil issue
The Glide problem
The Heat Transfer Coefficient (HTC) issue
The Servicing issue
The Toxicity issue
The Flammability issue
The Training issue


The Ozone Depletion Potential:

R-22 refrigerant is allowed to be used in the USA till Jan 1st 2010 and till 2030 in India, as per the Montreal Protocol. Leaked refrigerant is not the sole cause of depletion of the ozone layer. The Ozone Depletion Potential (ODP) of R407C is 0, while that of R22 is 0.05.


The Global Warming Potential:

The 100 Year ITH Global Warming Potential in (kg CO2/kg) for the refigerants are similar:

HCFC-22 1,700 1,500
R-407C 1,530 1,525

GWP:

"The Global Warming Potential (GWP) of a gas relates the cumulative (integrated) warming over time caused by the emission of the gas to the cumulative warming caused by the emission of the same mass of CO2. The two basic factors that drive the GWP value are the “radiative forcing” (the infrared absorption of an incremental amount of the gas in the atmosphere) of the gas and the rate of decay of the gas in the atmosphere, compared to CO2. There are uncertainties in establishing quantitative values for both radiative forcing and atmospheric decay rate for both the fluorocarbons and CO2. As a result the IPCC estimated that the accuracy of the GWP values is+ 35%. As new data has been and continues to be developed, GWP values have been revised and are subject to future revision. A detailed presentation of the methodology for determining GWP is contained in [IPCC [2001]. The fundamental importance of GWP values to this study is that it permits the warming impact of fluorocarbon emissions to be compared to the warming impact caused by energy consumption (and the associated CO2 emissions) for the various applications that make use of HFCs."

Fluorochemical 100 Year ITH GWP (kg CO2/kg)
TEWI-3 Appendix B Climate Change 1995 WMO 19993 Climate Change 2001

HCFC-22 1,700 1,500 1,900 1,700

R-407C 1,530 1,525 1,984 1,653


Reference:
http://www.arap.org/adlittle/appendixb.html


Zeotropes and Non-zeotropes:

R407C is a non-azeotropic (zeotropic) refrigerant mixture of Contains R-32, R-125 and R-134a (23/25/52 weight-%) and exhibits a quite different condensation phenomenon from those of R22.


The Lubricating Oil issue:

R-22 refrigerant requires that the lubricating oil in the compressor may be mineral oil, whilst for R-407C, specifically synthetic Polyolester or POE oils need to be used, as R407C does not contain chlorine, and therefore cannot dissolve mineral oil.While these oils are considered to be superior oils, less liable to breakdown, however they are more hygroscopic – they must therefore be kept from contact with air as far as is practical.


The Glide problem:

Unlike R22, R407C is a mixture of three refrigerants, which boil at different temperatures. As a zeotrope, R407C exhibits a phenomenon known as ‘glide’, that is changing state (evaporating or condensing) over a range of temperatures. 'Glide' has an adverse effect on the performance of conventional, mixed flow, shell and tube heat exchangers. For best performance, R407C should be used in plant with counterflow plate heat exchangers. 'Glide' can also increase the risk of freeze-up, in the event of a loss of flow or a localised restriction in the evaporator.

Since R407C is a zeotrope, the mixture will fractionate should a leak occur from a part of the system that contains both vapour and liquid. Service techniques have to be adapted in the light of this characteristic. After a significant leak, a moderate loss of refrigerant R407Cwill require the entire charge to be removed, before the system can be pressure tested, repaired, and fully re-charged. In short, systems will no longer be able to be topped up.


The Heat Transfer Coefficient (HTC) issue:

"In this study, condensation heat transfer coefficients (HTCs) were measured on a horizontal plain tube, low fin tube, and Turbo-C tube at the saturated vapor temperature of 39 °C for R22, R407C, and R410A with the wall subcooling of 3–8 °C. R407C, a non-azeotropic refrigerant mixture, exhibited a quite different condensation phenomenon from those of R22 and R410A and its condensation HTCs were up to 50% lower than those of R22. For R407C, as the wall subcooling increased, condensation HTCs decreased on a plain tube while they increased on both low fin and turbo-C tubes. This was due to the lessening effect of the vapor diffusion film with a rapid increase in condensation rate on enhanced tubes. On the other hand, condensation HTCs of R410A, almost an azeotrope, were similar to those of R22. For all refrigerants tested, condensation HTCs of turbo-C tube were the highest among the tubes tested showing a 3–8 times increase as compared to those of a plain tube."

Reference


The Servicing issue:

"Clean installation practices, effective leak testing and de-hydration and the weighing of additional refrigerant requirements remain vital. But all of these procedures have long been associated with R22 and indeed any other refrigerants."

"Concerns have been expressed that a moderate loss of refrigerant will now require the entire charge to be removed, before the system can be pressure tested, repaired, and fully re-charged. In short, systems will no longer be able to be topped up. Once again, this is no different to the procedures required with R22 but supports the case for ensuring that the system is leak free at installation.

There are seriuos issues relating to the use of R407C refrigerant, especially when servicing work needs to be carried out at site post-installation. The vendor has to ensure that:"
It will however be necessary to add R407C as a liquid, to ensure that the correct mix is added.

"In operation, R407C provides a number of indications that, if applied to R22 would indicate that the system were overcharged. Although slight, the following changes may be anticipated:

Higher head pressure
Lower compressor superheat
Lower refrigerant temperature difference across the condenser.
Also there may be frosting at the evaporator inlet."


Equipment

1. All equipment used with the new refrigerant and oil must be compatible.
2. Vacuum pump should be compatible however provided that oil is regularly changed it can be universal.Leak testers that rely on a reaction with chlorine (i.e. halide) will not work with R407C.
3. Gauges should be universal however do provide a means of contamination between oil types. Purge and blow through with OFN if in doubt.
4. Reclaim unit – dedicated to refrigerant.
5. Reclaimed refrigerant cannot and should not be re-used, which is difficult for the customer to monitor.
6. R407C has to be charged in the liquid state. This implies that some sort of chilling device (usually ice), would be required in case the unit needs to be re-charged at a site.
7. The condensing pressure of R407C is about 10% higher, providing a derated performance. Guage manifolds for service must be suitable for this higher pressure.
8. R407C being an HFC refrigerant, is extremely susceptible to mixing of impurities (oil, water, pipe during brazing) as compared to R-22 refrigerant.

Reference:
http://www.aquaair.org/R22-R407C-Differences.html


The Toxicity issue:

Refrigerants are divided into two groups according to toxicity:

Class A signifies refrigerants for which toxicity has not been identified at concentrations less than or equal to 400 ppm;

Class B signifies refrigerants for which there is evidence of toxicity at concentrations below 400 ppm.

R-22 is non-toxic, and no data is available about the non-toxicity of R407C below a concentrationm of 400 ppm, implying that R407C is toxic above 400ppm on prolonged exposure, though the toxicity levels of both refrigerants has been defined as A1 based on Safety Group Classification.

Classification of R-407C: R32/R125/R134a (23/25/52)- A1


The Flammability issue:

Refrigerants are divided into three groups according to flammability:

Class 1 indicates refrigerants that do not show flame propagation when tested in air at 21°C and 101 kPa;

Class 2 indicates refrigerants having a lower flammability limit of more than 0.10 kg/m3 at 21°C and 101 kPa and a heat of combustion of less than 19 kJ/kg;

Class 3 indicates refrigerants that are highly flammable as defined by a lower flammability limit of less than or equal to 0.10 kg/m3 at 21°C and 101 kPa or a heat of combustion greater than or equal to 19 kJ/kg.

Mixtures, whether zeotropic or azeotropic, with flammability and/or toxicity characteristics which may change as the composition changes during fractionation, shall be assigned a safety group classification based on the worst case of fractionation.

Reference:
http://www.fluorocarbons.org/en/applications/refrigeration.html


The Training issue:

Train-the-Trainers in Good Practices in Refrigeration Train-the-Trainers in Good Practices in Refrigeration. The Networking activity is managed by the Network and Policy Manager based at UNEP DTIE in Paris, France.
http://www.uneptie.org/ozonaction/news/mpaw.htm

Action pack for Schools:
http://www.uneptie.org/ozonaction/information/mmcfiles/4820-e-EdPack_1_guide_low.pdf.pdf

Check out the R407C - The Engineers Guide. Mitsubishi Heavy Industries
www.3dair.co.uk/download-files/r407c-guide.pdf

Read more on this article...

End of post Read more on this article...

Coming soon.

DesignBuilder CFD has been specifically designed to provide users with a tool that can be used to predict airflow and temperature distribution in and around buildings using the same methods as the general purpose pure CFD packages but at a fraction of the cost and without the need for any specialist knowledge.

Some of the key DesignBuilder CFD features:
3-D CFD grids are generated automatically from model geometry and boundary conditions using algorithms to promote optimal solution convergence.

The CFD engine has been developed around the SIMPLER algorithm, which belongs to one of the most widely used families of CFD solution methods. Turbulence can be modelled using the widely researched and documented k-e model and there are plans to introduce additional models for specific applications.

The interface incorporates tools to enable a wide range of boundary conditions such as supply diffusers, extracts, temperature patches, etc. to be assigned to room surfaces. A component library is also provided to enable radiators, fan-coil units, furniture, occupants, etc. to be located anywhere within the model and automatically incorporated within the analysis.

Boundary conditions can be automatically assigned from a previous EnergyPlus simulation.

3-D CFD results are displayed using the DesignBuilder OpenGL graphics engine providing impressive, easy-to-interpret images and movies of velocity vectors, temperature contours, iso-surfaces, particle streams, etc.

Read more on this article...

There is always a possibility that over the long term, your workstation seating height and the other egronomic details of your table could actually give you a severe backache and spondilytis.

Here's a nifty interactive web application which determines the work station and seating heights based on your height. End of Post Read more on this article...

May have finally come to an end. If you are wondering why the previous post has been struck off, then blame it all on my CSS wizard. I listen intently to what she speaks, and the point was subtly drilled home that a site made in Wordpress was going to look more or less like this blog. A site made by an amateur. A site not befitting the status of the organisation. Which actually summarises to a "Don't be nuts", or even a mere "hah"!.

Open-source Umbraco 3.02 (the current version has been released, and from what I read, this may turn out to be another gem similar to the Dasblog 1.6 engine running www.hvacindia.com .



Umbraco 3.02 build:
http://www.codeplex.com/umbraco/Release/ProjectReleases.aspx?ReleaseId=5136

What can Umbraco do? Basically, everything I want, plus the fact that the it has a flexible template design, and also CSS templates for documents.


Here's a summary:

Create document types with whatever properties you want.
Add/edit content on your site.
Set your XHTML and CSS templates for different document types.
Upload and use photos and other images.
Create a basic membership system, to allow logged in people to view certain sections of your site.
Create separate user accounts with customizable permissions to access the back-end to write, edit and publish content.
Have a multi-lingual site.
Create dynamic navigation and pull your content dynamically (aka showing "latest" items on the homepage).
Have your site consume RSS feeds.

The additional feature of creating a membership system, and create separate user accounts can be a very valuable feature for a Society website, going forward.

Frankly, the thing which really got me excited was the fact that Umbraco was 100% compatible with Windows Live Writer which is Beta 3 now, and looks pretty good.
http://get.live.com/en-us/betas/writer_betas

There are a huge amount of plug-ins available for Windows Live Writer Beta 3 here.

Take a look at Sites running Umbraco 3.x

You need, For local development and production hosting:

A Windows 2000+ computer with an installed web server (either IIS, or other that supports ASP.Net)
Microsoft SQL Server (MSSQL) or Microsoft SQL Server Desktop Engine (MSDE) or SQL Server 2005 Express
Edition.
ASP.Net 2.0 (to run umbraco v.3.x) installed.
Internet Explorer web browser to interact with the CMS back-end (websites created are viewable on any
browser your HTML code supports)

Finally, a website "package" to check out, which would demostrate the amazing power of Umbraco: (rename zip to umb before importing the package).
http://www.creativewebspecialist.co.uk/wp-content/uploads/2007/06/creativewebpackage_v096.zip
Read more on this article...