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Validated, easy to use HVAC Loads, Piping and Ductwork Design Software Tools

We know the feeling of suspicion and mistrust to existing software tools because the tools conceal algorithms behind nice user interfaces and provide no evidence of the accuracy of the results.

 

-What are the algorithm limitations?

-What is the accuracy of the results?

-Does it take into account such and such aspects of the process at hand?

 

To make your HVAC design pleasant and effective we developed new software tools meeting the following criteria:

-The tool calculation methods go through rigorous validation procedure allowing you to see if the accuracy meets your requirements. The calculation outputs have been matched against the sample calculations provided by the sources of the methods. Click here to see the validation test summary of the training and reference guide 'A to Z HVAC Design for Engineers'

-Module code is completely exposed. You can trace every line of the entire chain of the calculations and see the formulae used and their results

-User interface is based on the all-familiar MS Excel. This gives you the flexibility to customize your work and link the tool to your own spreadsheets

-Modular approach. The modules cover virtually all tedious and error prone calculating procedures related to the HVAC Systems Design. If you require, as an example, to size a water piping system, simply obtain the module 'Water Flow' with no prerequisites to other components (see complete list of modules we offer under 'Products' menu).

Link the modules into a comprehensive computing system, no need for manual input data transferring and editing the calculations any more. For example, if the architect changed the window type, simply change the U-value in the module interface as needed and immediately obtain the new size of all air-handling unit elements, ducts, even piping serving the spaces with new windows. This approach significantly reduces the time and dramatically improves accuracy in everyday engineering.

Module 'Design Loads'

ParameterTest sourceUnitsActualSimulatedDeviation
Solar irradiance Single-room example, p.30.32 /1/ Btu/h/ft2 205.4 205.4 0%
Solar-temperature same oF 156 156.4 0%
Lighting cooling load same Btu/h 1122 1123 0%
Wall cooling load same Btu/h 602 572 5.2%
Cooling load of windows without blinds same Btu/h 5636 5542 1.4%
Cooling load of windows with blinds same Btu/h 4310 4254 1.1%
Room heat loss same Btu/h 8495 8513 -0.2%

Module 'Water Flow'

Friction loss rates in ft w.c./100ft at 60oF water flow rate 10 US gal/min
Duct diameter, in.Test sourceSource valueBy module (Galvanized steel)By module (Uncoated carbon steel)
¾ Friction chart /1/ 25.0 23.9 20.8
1 same 7.0 7.04 6.32
1 ¼ same 1.8 1.79 1.65
1 1/2 same 0.9 0.83 0.78
Duct diameter, in.Test sourceActualBy module (Galvanized steel)By module (Uncoated carbon steel)
2 Friction chart /1/ 19 19.06 16.27
2 ½ same 7.2 7.69 6.69
3 same 2.5 2.56 2.28
4 same 0.52 0.65 0.6
Average deviations for using galvanized steel and carbon steel are 0% and -11%, respectively. Chapter 2 /1/ states that the module’s formulae are more accurate than the chart.

Module 'Psychrometrics'

ParameterTest sourceUnitsActualPredictedDeviation
Atmospheric pressure Chapter 6 /1/ In. Me 29.921 29.921 0%
Dry-bulb temperature same oF 100 100 0%
Wet-bulb temperature same oF 65 65 0%
Humidity ratio same lb/lb 0.0052 0.0053 -2%
Enthalpy same Btu/hlb 29.8 29.8 0%
Relative humidity same % 13 13 0%
Specific volume same ft3/lb 14.22 14.25 0%
Dew-point temperature same oF 40 40.3 -1%

Module 'Thermal Comfort'

ParameterTest sourceUnitsTest #1Test #2Test #3Test #4
Metabolic heat production Appendix D /4/ met 1.1 1.1 1.1 1.1
Insulation of clothing same clo 1.0 1.0 1.0 1.0
Indoor air temperature same oC 19.6 23.9 25.7 21.2
Indoor air temperature same % 86.0 66.0 15.0 20.0
Mean radiant temperature same oC 19.6 23.9 25.7 21.2
Air velocity same m/s 0.1 0.1 0.1 0.1
Actual PMV same -0.5 0.5 0.5 -0.5
PMV by module -0.47 0.49 0.54 -0.45
Actual PPD same 10% 10% 10% 10%
PPD by module 10% 10% 11% 9%
Metabolic heat production Appendix D /4/ met 1.1 1.1 1.1 1.1
Insulation of clothing same clo 0.5 0.5 0.5 0.5
Indoor air temperature same oC 23.6 26.8 27.9 24.7
Indoor air temperature same % 67.0 56.0 13.0 16.0
Mean radiant temperature same oC 23.6 26.8 27.9 24.7
Air velocity same m/s 0.1 0.1 0.1 0.1
Actual PMV same -0.5 0.5 0.5 -0.5
PMV by module -0.46 0.55 0.52 -0.46
Actual PPD same 10% 10% 10% 10%
PPD by module 9% 11% 11% 9%

Module 'Air Flow'

Duct diameter, in.Test sourceUnitsActualBy moduleDeviation
26 Chapter 35 /1/ Inch w.c./100ft 0.08 0.08 0%
22 same same 0.195 0.190 3%
18 same same 0.50 0.52 -4%
14 same same 1.99 1.85 7%
Average deviation is 1.5%.