The Google of 3D

Friday, September 28, 2007

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...

Posted by Kaks at 9:56 PM 0 comments  

What Outside Design Conditions should I use in calculating a heat load?

Tuesday, September 25, 2007

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...

Why the Global Warming Potential of a refrigerant should figure in your decision.

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...

Posted by Kaks at 9:10 AM 0 comments  

New age Refrigerants

Monday, September 24, 2007

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...

Designing Effective Powerpoint Presentations

Tuesday, September 18, 2007

Posted by Kaks at 6:38 PM 0 comments  

DesignBuilder 3-D CFD




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...

Check your posture


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...

Posted by Kaks at 10:57 AM 0 comments  

The search for the Holy Grail of CMS systems

Saturday, September 15, 2007

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...

Posted by Kaks at 5:10 AM 0 comments  

Ugrading the existing Society static html website.

Sunday, September 9, 2007

Currently, the website is in static html, and requires editing of html pages to update content.
It does not have the features which are so neccessary today, such as RSS feeds.



I am proposing to upgrade the Society website using WordPress, a free blogging engine, and the basic Kubrick theme since this theme is very stable, and easy to customise as per our needs.

A few useful sites to browse to achieve this aim would be:

WordPress download:
http://wordpress.org/download/

Installing WordPress:
http://codex.wordpress.org/Installing_WordPress

5 minute install:
http://wordpress.org/docs/installation/5-minute/

Step by Step WordPress Installation:
http://www.gnc-web-creations.com/wordpress-installation.htm

Customise your webtheme:
http://www.vandelaydesign.com/blog/design/customize-your-own-wordpress-theme/


Read more on this article...

Posted by Kaks at 3:32 AM 0 comments  

HLCP - The simple test case, IP and SI

The IP example:




Click to enlarge


The almost equivalent SI example:






Read more on this article...

Posted by Kaks at 1:52 AM 0 comments  

DesignBuilder, first one of the block.




Interested in whole building energy performance, including HVAC? Look no further. Download a 30 day trial version of DesignBuilder and check it out for yourself.



DesignBuilder is one of the first whole building energy performance simulation programmes, including simplified models of HVAC systems, and uses the validated EnergyPlus simulation engine.

http://www.designbuilder.co.uk/

Designbuilder has a great demo here:

http://www.designbuilder2.co.uk/tutorials/DesignBuilderDemo.htm

DesignBuilder offers a 50% discount for educational institutions.

Read more on this article...

Posted by Kaks at 12:42 AM 0 comments  

HLCP Help file specifications

Thursday, September 6, 2007

HLCP requires that a suitable graphical help file be provided.

The Help file is a combination of still screenshots with text boxes, and short animated screen captures, for each "How To" for HLCP, basically to focus on how to get things done, rather than explain everything. Information needs to be presented in a logical manner so that the work flow is clear.



Since it is presumed that the user is familiar with HVAC Load calculations, there is no link to any "Reference" as such, but brief introductionary details shall be provide in text boxes on static screens to explain certain features such as "Project Masters", Schedule Masters", etc. which may be new to the HVAC engineer experienced only in manual Heat Loads .

To meet this end, an sectionalised HTML Help file, each section being a mix of static screenshots with dialogue boxes giving explanations, and short animated swf flash screen captures, which show an animated mouse cursor actually performing a certain task

The final file shall be a set of swf files, linked to HTML files, which can be accessed through the menubar of HLCP or even ported to a website.

"Wink" shall be used to create the animations, and "Shalom Help Maker v 0.6.1" shall be used for the compiled help file.

Download links here:


Wink

http://www.debugmode.com/wink/download.php


Shalom Help Maker

http://www.danish-shareware.dk/soft/shelpm/

You will need the compiler files for turning your project (the shp file and images) into a help file.


Help Compiler

http://www.danish-shareware.dk/soft/shelpmbeta/helpcompiler.zip


A preliminary broad index for the various Sections of the Help file is given below. (Note that within these sections, there would be sub-sections, i.e., that for each section, we may need subdivided sections to cover all aspects.

The proposed sections (index) of the HLCP Help.

Index for HCLP Help file.

Introduction to HLCP
What is HLCP?


Starting HLCP
Accessing the Getting Started pdf file
Accessing the FAQ pdf file


Defining a Building

The HLCP Environment
The Menubar
The tab bar
Getting Help

The user files
eplusout.csv
PostProcess.csv

projectname_input.csv
projectname_postprocess.csv
projectname.pdf

What is a Project
Starting a new Project
Opening an existing Project
Filling in Project Details
Saving a Project
Deleting a Project
Deleting a Project Master
Deleting a Schedule Master

Projects Tab

Selecting the units
Location / Weather Tab
Selecting the location
Selecting the Weather Data source
Selecting the City
Selecting the Range

Project Master tab

Project Masters Tab
What is a Project Master
Creating a new Project Master
Loading an existing Project Master
Saving a Project Master

Select the Project Master tab
Selecting a U value for the Project Master
Adding / deleting a value in the Project Master
Changing default safeties

U value calculator

Opaque U value calculator
What is the opaque U value calculator
Film coefficients
Maximum number of layers
Order of layers
Units

How to create a new opaque Construction...
How to select and transfer an opaque Construction...
How to delete an opaque Construction
How to add a U value directly
Exiting the U value Calculator

How to create a new window Construction...
How to select and transfer a window Construction...
How to delete a window Construction
How to add a U value directly*
Exiting the U value Calculator


Shedule Master tab

What is a Schedule Master
Creating a new Schedule Master
Loading an existing schedule Master
Saving a Schedule Master

System Details tab

What are System Details
Adding a new System
Deleting a System
Duplicating a system
Inside Design Conditions
Bypass factor
System multiplier

Zone Details tab

Defining a new Zone
Entering basic Zone details
Drawing a Zone
Saving a Zone

Entering Wall/ Partition details
Entering Window details
Entering shade (external to window) details
Entering Blinds / Drapes details
Entering Door details
Entering Floor details
Entering Flat Roof/Ceiling details
Entering Skylight details
Entering Gable Roof details

Internal Loads tab

Entering Occupancy details
Entering Infiltration details
Entering Heat Recovery details
Entering Ventilation Air details
Entering Equipment details
Entering lighting details

Input Summary tab

Reports tab

What are seasonal loads
What are monthly loads
What are hourly loads

Selecting the output type required.
Adding a monthly time period
Adding a hourly time period

The Run tab

Save and Simulate
Save and Simulate Later

The Outputs Tab

The Seasonal load output
Accessing the output csv files

The Error window

Read more on this article...

Posted by Kaks at 1:09 PM 0 comments  

HLCP: Some possible user errors that I've documented.

Useful as a common error list in HLCP documentation.


List of Likely Errors in data Entry:

While an extensive Help file, with animations has been provided, you may still face a few user errors. A list of possible common errors are given below. If you face errors while executing HLCP, check this error list first before contacting:



1. If you are seeing the Seasonal Load pdf output has lengths, breadths and areas far larger than they should be, (especially a multiple of 3.28 for lengths, or 10.76 for areas), it could mean that you are working in the SI units thinking that you are working in IP units, and vica versa.

2. If you see a severe or fatal error in the error screen, then possibly you did not "save" all schedules.

3. If you do not see the schedule populating a drop-down list, then you did not "save" all schedules.

4. Always "exit" HLCP after doing a calculation, and re-start HLCP to prevent faulty threading. If for any, reason, you still face errors, re-boot. This is not merely a "file" that you are dealing with. These are database "tables" and such problems occur sometimes, due to open threads (processes) and open tables, causing a conflict. It does not mean it's a bug.

5. If you face errors, please clearly define the error, and if possible attach a screen-shot (by using the "PrtScr" key on your keyboard, and send your query to "hlcp.support@gmail.com" It will be answered promptly. Only queries related to the working of the progamme shall be answered, not queries related to the theory of calculating cooling loads.

6. We expect values entered to be in a reasonable range, and that unusual values are not entered, so that the programme functions normally. Be especially careful of entering values null "0" values (in lengths for example), or negative values. There are no user entries which are negative.


7. If the hourly load is taking an unusually long time, please note that 8760 hour hourly loads will take time due to the extensive post-processing involved. To improve calculation times, increase the RAM. ensure that you have installed HLCP on a machine which has components rated higher than the "minimum" mentioned.


8. Just after a simulation, HLCP seems to hang. I am unable to click any tab.

This happens sometimes, because just after a run a small window pops up with the text "Successfully Completed"" and the OK button needs to be clicked. This small window sometimes is hidden behind the HLCP screen. In Windows XP, minimise all screens by pressing "ctrl d" and then maximise the small window and click "OK".

9. If you have made a mistake of not entering an item in the Project Master, and therefore do not see it in the dropdown box, remember, you cannot go back to the Project Master, add a new item, and expect it to become visible in the dropdown box! you wuold be forced to start the Project all over again. So, do fill up the Project Master correctly, and don't forget to SAVE it.
Read more on this article...

Posted by Kaks at 1:00 PM 0 comments  

EnergyPlus utilities

In the process of working on HLCP, I came across a few utilities which proved to be very useful during testing. These utilities can also be used on the .eso and .dxf files generated for the project by EnergyPlus through the HLCP interface.



xEsoView


xEsoView is a file viewer for Energy+ .eso output files. xEsoView uses the Qwt extension of the Qt toolkit from Trolltech Inc.

http://xesoview.sourceforge.net





DrawEzPlus


DrawEzPlus is a 3-D rendering tool that reads the geometry data in an EnergyPlus input file and uses a set of OpenGL commands to render the building objects. Two key steps are involved. First, the E+ input file is parsed and all vertices data is extracted into a temporary file, organized by type of building object. Second, the temporary file is processed by a set of OpenGL utilities that produce renderings of the 3-D data.

To Download DrawEzPlus 1.1, click here.
Courtesy: The Deringer group

Read more on this article...

Posted by Kaks at 12:23 PM 0 comments  

HLCP Version 1.0 brochure text preview (Beta)

Wednesday, September 5, 2007


HLCP has been developed and promoted by ISHRAE, "The Indian Society of Heating, Refrigerating and Air Conditioning Engineers".


HLCP, Hourly Load Calculation Programme.

HLCP software enables calculations of design day and hourly cooling loads from user entered data.

FREE upgrade to Version 1.1 for purchasers of Version 1.0!

Highly subsidised pricing by ISHRAE.


INPUTS

Engineer-friendly numerical inputs through an easy tabbed Windows graphical user interface.
Help file with screenshots for step-by-step guidance for inputs available in both pdf and html formats.


OUTPUTS

Output available in pdf format for Design Day loads.
Output available in Microsoft Excel or csv format for for 288 hour and 7680 hourly loads.


Why HLCP*?


FEATURES

Friendly graphical user interface.
WeDCo and BIS (Bureau of Indian Standards) design conditions.
Uses the validated Energyplus simulation engine which is based on heat balance method.
Self-shading of the building.
Wall and roof tilts.
Window external shading and reveal effects.
Treated fresh air.
Design Day cooling loads.
288 hour monthly cooling loads.
7860 hourly annual loads.
Schedules for occupancy, lighting and equipment.


WEATHER DATA

WeDCo Hourly weather data for 58 stations.
WeDCo Design Day weather data, 2%,1% & 0.4% for 58 stations.
ASHRAE Hourly and Design Day weather data for 8 stations.

Stations covered:

Ahmedabad, Akola, Allahabad, Amritsar, Aurangabad, Bengaluru, Barmer, Belgaum, Bhagalpur, Bhopal, Bhubneshwar, Bikaner, Chennai, Chirtadurg, Dehradun, Dibrugarh, Gorakhpur, Guwahati, Gwalior, Hissar, Hyderabad, Imphal, Indore, Jabalpur, Jagdelpur, Jaipur, Jaisalmer, Jamnagar, Jodhpur, Jorhat, Kolkata, Kota, Kurnool, Lucknow, Mangalore, Mumbai, Nagpur, Nellore, New Delhi, Panjim, Patna, Pune, Raipur, Rajkot, Ramagundam, Ranchi, Ratnagiri, Raxaul, Saharanpur, Shillong, Sholapur, Sundernagar, Surat, Tezpur, Thiruchchirapalli, Thiruvananthapuram, Veraval, Vishakhapatnam

Developed and promoted by ISHRAE, "The Indian Society of Heating, Refrigerating and Air Conditioning Engineers".


* Product suitable for installation on a single machine.

*For educational purposes only


Trademarks:

BIS© is a copyright of Bureau of Indian Standards

Microsoft, Windows, MS Word, MS Excel, and MS PowerPoint and/or other Microsoft products referenced herein are either trademarks or registered trademarks of Microsoft Corporation.

Intel© is a copyright of Intel Corporation.

EnergyPlus© 1996-2004 is a copyright of The Board of Trustees of the University of Illinois and The Regents of the University of California through the Ernest Orlando Lawrence Berkeley National Laboratory. All rights reserved. EnergyPlus is a trademark of the United States Department of Energy).

Sales Contact:

ISHRAE Mumbai Chapter
ishrae_m@vsnl.com

HLCP support:

hlcp.support@gmail.com

Webpage:

http://hvacindia.com/hlcp/

Read more on this article...

Posted by Kaks at 1:22 PM 0 comments  

HLCP FAQ

HLCP has been developed and promoted by ISHRAE, "The Indian Society of Heating, Refrigerating and Air Conditioning Engineers".


1. What is EP and HLCP?


EnergyPlus (EP) is a simulation engine. Normally it is used in conjunction with a graphical user interface. HLCP (Hourly Load Calculation Programme) is a graphical user interface for designday and hourly load calculations for Indian cities.




2. What is WeDCo?


WeDCo means: Weather data and Design Conditions for India


3. How do I model Thermal zones? (Courtesy Energyplus, text reproduced from "Getting started.pdf"


This section provides a step by step outline that will help you streamline creating your building models for using HLCP.

Step 1: Checklist before you start to construct your input file:

EnergyPlus requires some information in specified, externally available formats; other information may require some lead time to obtain. The following checklist should be completed before you start to construct your input file.

Obtain location and design climate information for the city in which your building is located. If possible, use one of the weather files available for your weather period run.

Obtain sufficient building construction information to allow specification of overall building geometry and surface constructions (including exterior walls, interior walls, partitions, floors, ceilings, roofs, windows and doors).

Obtain sufficient building use information to allow specification of the lighting and other equipment (e.g. electric, gas, etc.) and the number of people in each area of the building.

Obtain sufficient building thermostatic control information to allow specification of the temperature control strategy for each area of the building.

Obtain sufficient HVAC operation information to allow specification and scheduling of the fan systems.

Obtain sufficient central plant information to allow specification and scheduling of the boilers, chillers and other plant equipment.


Step 2: Zone the systems


In the general sense, there are two types of "surfaces" in EnergyPlus. These are:

1. heat transfer surfaces and
2. heat storage surfaces

The first rule of building modeling is, "Always define a surface as a heat storage surface unless it must be defined as a heat transfer surface". Any surface, which is expected to separate spaces of significantly different temperatures, must be defined as a heat transfer surface. Thus, exterior surfaces, such as outside walls, roofs and floors, are heat transfer surfaces. Interior surfaces (partitions) are heat storage surfaces if they separate spaces maintained at the same temperature and heat transfer surfaces if they separate spaces maintained at different temperatures. A discussion of how to define heat transfer and heat storage surfaces will occur in later steps. In order to correctly "zone" the building it is necessary only to distinguish between the two.

A "zone" is a thermal, not a geometric, concept. A "zone" is an air volume at a uniform temperature plus all the heat transfer and heat storage surfaces bounding or inside of that air volume. EnergyPlus calculates the energy required to maintain each zone at a specified temperature for each hour of the day. Since EnergyPlus performs a zone heat balance, the first step in preparing a building description is to break the building into zones. The objective of this exercise is to define as few zones as possible without significantly compromising the integrity of the simulation.

Although defining building zones is somewhat of an art, a few general rules will keep the new simulation user out of trouble.

The inexperienced building modeler may be tempted to define each room in the building as a zone, but the thermal zone is defined as a volume of air at a uniform temperature. The general rule then is to use the number of fan systems (and radiant systems) not the number of rooms to determine the number of zones in the building. The minimum number of zones in a general simulation model will usually be equal to the number of systems serving the building. The collection of heat transfer and heat storage surfaces defined within each zone will include all surfaces bounding or inside of the space conditioned by the system.

1. Notice that Zones 4 and 7 include two rooms that are not adjacent to one another but are served by the same system. Because the air temperature in the two spaces is maintained at the same uniform temperature, the two spaces, though separated spatially, may be defined as a single zone. For our purposes, we will define them as separate zones.

2. Notice that Zone 1 and Zone 2 are served by the same fan system and could be defined as a single zone with 7650 cfm of conditioned air supplied to the space. The space was split into two zones because the designer expected higher solar loads on the South and West sides of the wing and wanted to examine the distribution as well as the magnitude of the load in the space.

When the building was zoned our objective was to define as few zones as possible.


Step 3: Prepare to Construct the Building Model:


Working from blueprints or sketches and following the guidelines in Step 2, the building zones were determined. It is recommended that the engineer sketch the building with its zones. Surface dimensions should be included in the sketch. Additional geometric and surface information is required before an input file describing the building can be constructed.

Compile surface and subsurface information.:

Building information:

Building North Axis: This syntax simplifies building geometry specification by designating one wall of the building as the building's north pointing axis. The building model North axis is measured from true (compass) North. Surface facing angles (see surface information below) are then specified relative to the building north axis.

Zone information:

Wall height: This is entered once. All walls are assumed to be the same height. If the height for a given wall differs from the specified height, the wall length should be adjusted by the user to give the correct equivalent area. In certain conditions this may not be possible and you will need to resize each wall accordingly.

Surface information:

1. Base Surface Type: Heat Transfer/Heat Storage Surfaces may be of the following types: wall, floor, roof, internal mass, or subsurface.

2. Construction: The type of construction of the surface (see previous table).

Subsurface information:

1. Subsurfaces are Windows, Doors or GlassDoors
2. Area: Area of the subsurface.
3. Reveal: For windows only, the distance it is inset from the outside surface of a wall.

Step 4: Finally Compile Internal Space Gain Data:



4. What are the outputs available from HLCP?

HLCP has three distinct and exclusive types of outputs.

Type 1:
Design loads - Design loads for summer, monsoon and winter based on WeDCo ambient design conditions. available as a pdf output, and also as a csv output.

Type 2:
Monthly loads - hourly loads are calculated for a 12 representative days corresponding to the 12 months of the year. Data for these 12 representative days are extracted from WeDCo. Available as a csv output.

Type 3:
Hourly loads are calculated for the user selected period (days). available as a csv output.


5. What HLCP would not do?


Dynamic Simulation by changing building parameters such as orientation, etc. (one could always do a kind of "manual" simulation by re-loading data with different parameters).

Input from CAD packages, and interfacing with the same.

Moisture adsorption and desorption in building elements, moisture load calculations, load calculations for cold stores, deep freezers (or calculations for DB temperatures below 18 °C, 60% RH and snow conditions).

Radiant heating and cooling systems, passive and solar systems.
Energy calculations, simulations and costs.
Sizing and optimizing cooling equipment.
Any special convolution required by a specific user.
Effect of heat recovery.
Interface with Linux, Macintosh, and link with TRNSYS, SPARK or other programs.
Effect of external shading such as adjacent buildings.


6. What are the features of HLCP over the conventional heat load calculations being used?


Self-shading of the building.
Wall and roof tilts.
Window external shading and reveal effects.
Treated fresh air.
Monthly loads.
Validated simulation engine.
WeDCo and BIS (Bureau of Indian Standards) design conditions.
Heat recovery.


7. Can I do heat loads for multiple buildings?


No. You would need to do separate runs.


8. Can I change the outside design conditions given for various cities?

No.


9. Can I import a CAD drawing into HLCP?


No.


10. What is a "Building", System" and "Zone", "Multiple zones" as defined in HLCP?


Energyplus input is from a thermal model made by the user, from the building geometry inputs. Output is of the thermal model only.

A "zone" is a thermal, not a geometric, concept. A "zone" is an air volume at a uniform temperature plus all the heat transfer and heat storage surfaces bounding or inside of that air volume. EnergyPlus calculates the energy required to maintain each zone at a specified temperature for each hour of the day. Since EnergyPlus performs a zone heat balance, the first step in preparing a building description is to break the building into zones. The objective of this exercise is to define as few zones as possible without significantly compromising the integrity of the simulation.


Geometrical Zones: (Pic courtesy Energyplus)



Thermal Zones: (Pic courtesy Energyplus)




The minimum number of zones in a general simulation model will usually be equal to the number of systems serving the building.

Thermal model:

Sketched by HVAC engineer.
Zone has a common temperature.
Walls have a common height.

Definition:

Building Building has Floors (Systems)
Floor (System) Floors have Zones (Zones)
Zone (Zone) Zone has uniform inside conditions.

Multi-zone (one)1 Building:

Building: "n" Floors (Systems)
"n" Zones

Block load: Single Building only.
One Floor (System)
One Zone

Building should be:
Closed polygon.

Technically speaking, there is no limit to the number of Zones, Surfaces, etc. that EnergyPlus can process. The input routines allocate according to how many of these the user enters. Practically speaking, your simulation may take longer with more complex / larger numbers of these items.


11. Does HLCP consider self-shading from walls?

Self shading on the building walls by other walls, will only be considered if the building is entered as one system and one zone, as would normally be done, for an hourly load calculation, which as it is, is for a single zone only. Else, multiple zones are "unconnected" so to speak, and self-shading is not considered.


12. Can I change the calculated ADP temperature and will it reflect the re-calculated dehumidified air quantity?

Yes.


13. Why do we have to create a "Project Master"?

A Project Master holds all the construction types being used in a building, chosen from the hundreds of constructions that you may created in the U value calculator.

Constructions from the Project Master are then available for selection in drop-down boxes as "construction names" for selection.


14. What is a Schedule Master?

A Schedule Master holds all definitions of schedules for the particular project. Schedule Masters can be saved for use with other projects. See Masters menu.

Refer ASHRAE 90.1,1-1989, section 13 for representative inputs.



15. Could you list out what is not possible with HLCP at this version?

100% fresh air applications.
Moisture transfer applications.
Direct import of CAD data.


16. Why are film coefficients missing from the U value calculator?

EP calculates the film coefficient based on exposure, wind speed and wind direction.


17. What is the time-step being used in HLCP?

1 hour.


18. Can I get some training in how to use HLCP?

Maybe, at a future date, though currently there is no formal training programme put in place by ISHRAE.


19. Can I consider any external wall as a shaded wall?

Yes.


20. How are psychrometric calculations done in HLCP?

Through a purchased DLL from a reputed source.


21. People: What does the "Activity Level" describe?

Activity level is the amount of heat generated by one person.
The values are obtained from 2001 ASHRAE Handbook of Fundamentals, page 8.7, Table 4.


22. Curtain Glazing: How can curtain glazing be handled in HLCP

The concept of curtain glazing is akin to a passive trombe wall system, which is a glazing + solid opaque wall. Currently, you would have to model this as a separate zone.


23. Should I measure the outside dimensions of walls, or the inside dimensions?

Size of the wall is always the internal measure, although we look at the wall from outside when describing vertices. As far as the simulation is concerned, the inside and outside measurements are identical from a heat-transfer perspective. So, one could argue that the average of the two is more appropriate to pick up the additional outside heat transfer.


24. What are the outputs available in an hourly load analysis? Could you describe the output of the hourly load calculations?


Through EnergyPlus:

Zone Window Heat Gain[W]
Zone Window Heat Loss[W]
Zone Opaque Surface Inside Conduction Gain[W]
Zone Opaque Surface Inside Conduction Loss[W]
Zone-Total Internal Latent Gain[J](Hourly)
Zone-Total Internal Radiant Heat Gain[J](Hourly)
Zone-Total Internal Convective Heat Gain[J](Hourly)
Zone-Total Internal Lost Heat Gain[J](Hourly)
Zone-Total Internal Visible Heat Gain[J](Hourly)
People-Sensible Heat Gain[J](Hourly)
People-Latent Heat Gain[J](Hourly)
People-Total Heat Gain[J](Hourly)
Lights-Total Heat Gain[J](Hourly)
TaskLights-Total Heat Gain[J](Hourly)
Electric Eq-Total Heat Gain[J](Hourly)
Electric Eq-Radiant Heat Gain[J](Hourly)
Electric Eq-Convective Heat Gain[J](Hourly)
Electric Eq-Latent Heat Gain[J](Hourly)
Electric Eq-Lost Heat Gain[J](Hourly)


Through Post-Processing:


SH (Sensible heat total)
LH (Latent heat total)
BVSH (Bypass value of sensible heat, ventilation air)
BVLH (Bypass value of latent heat, ventilation air)
NBVSH (Non-bypass value of sensible heat, ventilation air)
NBVLH (Non-bypass value of latent heat, ventilation air)
INSH (Sensible heat, infiltration)
INLH (Latent heat, infiltration)
RSH (Room Sensible Heat)
RLH (Room Latent Heat)
RTH (Room Total Heat)
LIGHTFRACT Sensible heat fraction, lights, return air)
GTH (Grand Total Heat)
RSHF (Room Sensible Heat Factor)
ERSH (Effective Room Sensible Heat)
ERLH (Effective Room Latent Heat)
ERTH (Effective Room Total Heat)
ESHF (Effective Sensible Heat Factor)
ISH (Sensible heat, infiltration)
SHR (Sensible heat, heat recovered)
LHR (Latent heat, heat recovered)


25. Are the inputs available as an output file?

Yes, in the form of a comma-delimited file, and a pdf file.

The file structure is as under:

1 Units;
2 Source of Weather Data, Location, DB Temp Summer, Monsoon, Winter, WB Temp Summer, Monsoon, Winter;
3 System name, Zone name, Rotation;
4 Walls/Partitions, Surface Name, Orientation, Exposure, Temp Diff, Length, Tilt, Construction name, U value;
5 Windows, Surface name, Window Name, Quantity, Length, Reveal, Height, Construction name;
6 Shades, Surface name, Window Name, Shade name, Overhang projection, Overhang elevation, Right fin projection, Right fin offset, left fin projection;
7 Doors, Surface name, Door Name, Quantity, Height, Width, Construction name, U value;
8 Flat roof, Ceiling,Ceiling Name, Length, Width, Area, Tilt, Exposure, Temp diff., Const. name, U value;
9 Gable roof, Roof Name, Length, Width, Height, Area, Tilt, Exposure, Temp diff., Const. name, U value;
10 Gable roof skylight, GableRoof name, Sky Light Name, Qty, Length, Width, Const. name, U value;
11 Floors, Ceiling Name, Length, Width, Area, Tilt, Exposure, Temp diff., Const. name, U value;
12 People, Nos, units, activity, Schedule name;
13 Lighting Flourescent, Value, units, ballast multiplier, Fraction return air, schedule;
14 Lighting incandescent, Value, units, Fraction return air, schedule;
15 Ventilation per person, Rate / quantity, total, units;
16 Ventilation air changes, Rate / quantity, total, units;
17 Treated fresh air, Qty, DB, WB, RH;
18 Equipment Sensible, Total, Diversity Factor, Fraction lost, Units, Schedule;
19 Equipment latent, Total, Units, Schedule;
20 Infiltration, Value, Units;
21 Schedule Occupancy, value, value, etc.;
22 Schedule Lights, value, value, etc.;
23 Schedule Equipment, value, value, etc.;


26. How do I enter numerical data in various units?

Data entry has to be in the units selected.

If SI units selected as default units:

a. Whole meters: xx or xx m
b. Decimal meters: xx.xx or xx.xx m
c. Centimeters: xx cm
d. Millimeters" xx mm

If Inch Pound (IP) units selected as default units:

a. Whole feet: xx or xx '
b. Decimal feet: xx.xx or xx.xx '
c. Feet-whole inches: xx '(space) xx "
d. Feet-Fractional inches: xx'(space)xx-1/xx"
e. Whole inches: xx"
f. Decimal inches: xx.xx"
g. Fractional inches: xx-1/xx"


27. Can I change the safety factors?

Safety factors are user-definable, and can be set as defaults. However the range of values which can be input is as under:

The limits for safety factors are 0 - 20 %.

The default values are as follows.

Sensible load safety = 3%
Supply fan heat gain = 5%
Return fan heat gain = 0%
Return air duct gain = 0%
Latent load safety = 3%
Pump and pipe losses = 0%"
Pump and pipe losses = 0%

(This is a part of the equipment load, not the room load. For centrally air
conditioned systems, the losses are taken to be 3% of the sum of
sensible and latent loads.)

Supply fan heat gains:

Supply fan heat gains could be taken as follows:

Up to 40 mm static pressure, 3%
Between 40 and 50 mm, 5%
Between 50 and 100 mm, 12%
Above 100 mm, 17.5%


28. How many layers can I have in a construction?

A maximum of 10 layers are permitted for layered constructions.

Layers are to be sorted, "Outside" to Inside" by user, unless the construction
is symmetrical, in which case it does not matter. Layers can be sorted


29. Are user-defined materials possible?

User defined materials and constructions are also possible.


30. Is there a limit to the thickness of a material in a construction?

Yes, the limit is 3 metres.


31. What enhancements are expected in version 1.1?

The major enhancements shall be:

1. Return air with plenum.
2. Direct entry of composite U values, and / or ECBC U values.
3. SI output of seasonal loads.
4. At least 6 more cities in the WeDCo database.


32. What is the minimum system requirements?

1. Seasonal and Monthly loads:

Windows® System OS:

* Intel Pentium® IV 1.7 GHz or eq. AMD.
* 512 MB or more of RAM
* 32 MB graphics card.
* 1.0 GB available HD space
* 24x CD-ROM drive
* A 56k or better Internet connection
(for registration only).

2. Hourly loads.

Windows® System XP OS:

* Intel Pentium® IV 2.4 GHz or eq. AMD.
* 1024 MB or more of RAM
* 64 MB graphics card.
* 2.0 GB available HD space
* 24x CD-ROM drive
* A 56k or better Internet connection
(for registration only).
Read more on this article...

Posted by Kaks at 11:53 AM 0 comments