View Full Version : Evaporative condenser cooling make an old dog bark

18-02-2016, 04:33 AM
I retrofitted a 45 year old 3 1/2 ton split AC unit that had a SEER of 8 when built with a large ...16 SQ FT evaporative precooler to the air intake to the small 5 SQ FT condenser.

I got this old dog to run at the same amps as a new 13 SEER American Standard packaged 31/2ton unit that has 18 SQ FT of condenser coils ... 18.6 amps at 220v and the new unit uses a scrol compressor while the old dog had a new piston Copeland compressor 2 years ago.

At 82F ambient the old dog will deliver 46F air to the home in just 10 minutes . The condensing temp is only 87F measured at the condenser coil exhaust side.

The air to the condenser is cooled from ambient to about 62F from precooling.

Anyone else had similar results from precooling an old dog.

Any danger to slug the compressor when condensing at such a low temp?

21-02-2016, 11:15 PM
If you live in a dry climate putting evaporative pad cooler around the condensor is an easy trick to raise efficiency provided your fan can pull enough static pressure and the coils are protected from added moisture in the intake air...there are also kits sold which use high pressure water atomizers to release a mist around condenser intake...the downside of adding humidity to air is that the dirt will cement up inside the condensor finds..

I have a samsung 18K split which is barely enough during summer nights of Riyadh as night time temps hoover at 46-48C. I put a make shift cooling pad behind it with a trough of water which is filled and then it is sucked up the pad by capillary action....makes a difference in performance but I was seein too low pressures so had to add some refrigerant..