Carrier HAP 4.42 vs 4.2

[aucklander]

Hi all!

I created two identical models, one in version 4.2 and the other in 4.41 of the Carrier HAP software. After checking everything three times, I did not find any difference in the parameters values, but the latest version of the software generates higher cooling requirement than the old version.

What could cause this? Was there a shift in the overall design intent? A colleague of mine and myself designed the same system with the same parameters, and the boss selected the other design as more accurate (old software 4.2) as the cooling load is lower and consequently the required plant is more economic... I checked everything, we are using the same parameters, areas, surface, glazing, etc...

Your help will be appreciated.

 

[HVAC68]

All products (even services and software) are subject to continuous improvement !!! There must have been some bugs in the program, which has got fixed !

HVAC68

 

[GMcD]

Or, as a software product put out by an air conditioning equipment manufacturer who wants to sell more/bigger air conditioning equipment, a few more safety factors got thrown in...Call me cynical.....

 

[ChrisConley]

Any change in ventilation rates? HAP4.42 uses the most current version of ASHRAE 62, if you left the outdoor air rates as default it would have likely lowered the ventilation requirements, and the cooling along with it.

 

[DrRTU]

If you are a registered user, call (800) 253-1794 and the support duty person will call you back. They should be able to explain the difference. Did you save the data file for export then open the data in v4.1? I Did the same process on a few LEED projects re: HAP 4.34 to 4.40 and the numbers did not change. I would go line by line on the Design Load Summary page to see which lines changed. My bet is OA.