Hello,

This is my first time to the forums here, hopefully you guys can help me out.

I have a Stainless Steel Nema 4X enclosure that is 84"H 24"D 48"W. I was trying to size a Thermo Electric Heat Exchanger from a supplier. I have ~ 500 Watts in my enclosure, with direct sunlight, external temperatures of 105F and Delta P required of Degrees (Max internal Temp 90F).

The supplier stated with R12 Insulation and there 2500 BTU Exchanger i can achieve 16Degrees Delta; however, there 2500 BTU exchanger is not C1Div2 rated so i have to use there 1500 BTU Heat Exchanger.

Now im no genius but if i have 2 heat exchangers, i would have a cooling capacity of 3000 BTU? But when they performed there magic calculation that they wont tell you how they get they said with the two 1500 BTU Heat Exchangers i would only get 10 degrees Cooling.....


Does this sound right to you, because i use to work for a company that supported Telecom and while i wasnt an engineer or involved in sizing air conditioners i dont be worked with some of the people on occasion and dont recall an stipulation or anything about having more heat exchangers lower the cooling capacity.


I know its harder and harder to increase Delta P and thers a point you wont get above ~ 25 degrees Delta P but if i have 2 x 1500 BTU heat exchangers should they not at least make up the cooling capacity and capability supplying at least the same minimum amount of Delta P as a 2500 BTU Unit?

These Heat Exchangers are new for us using, we normally use Vortec Coolers and don't experience problems. But i tell you chasing this tail has made me wake up at 3 AM this-morning and here i am typing on this forum. The attempt of this has become futile, mundane, and down right aggravating. Hopefully someone here can shine some light in a fashion i can understand why i don't get at-least the same cooling capacity out of a 17% increase in BTU Cooling Ratings.

- Thanks.