# testing of precooling condenser via evaportive



## doggone (Oct 10, 2011)

Thought you fellow HVAC pros might find this of interest.

First I have been testing the effect that precooling both the intake air through the evaporator and condenser coils of 8,000 and 10,000 BTU R22 window air conditioner having an EER of 9.8 typical of bargin window ACs you see at the home clubs.

I use a low resticion ( you san see through it) evaporitve pad to precool the intake air. The coils stay bone dry we do not spray water on the coils.

Well today in Arizona at 90F and 12% Rh ( we still have some 95F days left out here) we reduce the watt draw of a "8,000 BTU) AC from 850 watts to just 655 watts and we reduce the evaporator discharge temp by 7 to 8 F to the room to 42F This really increases the effective cooling by at least 1,000 BTU.

Using the presooler I reduce the air temp from 90 F ambientTo 64F for the intake air to both the evaporator and the condenser coils.

The math :

9000 BTU / 655 watts = 13.7 EER or 15.6 SEER not bad for a $99 window AC??

I will be this ona 3 1/2 ton SEER 7 central AC I expect to reduce the 6700 watt draw by a big number.


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