I've seen evaporative spray systems for condenser coils. Fouling or erosion of the coil or fins can be a problem. Why not put in an evaporative condenser?
Hello - Is it possible/advisable to add an evaporative cooler ahead of a standard residential heat pump?
Basically, I'm trying to precool the air with evaporation before it enters the coils of my outside heatpump.
Seems like a good idea, but I've never seen it. Any know why?
Thanks
David Sprunger
I've seen evaporative spray systems for condenser coils. Fouling or erosion of the coil or fins can be a problem. Why not put in an evaporative condenser?
Texasgrand - thanks for the reply. I already have two standard 3 ton air source heat pump units installed in our home (split systems w/air handlers in the attic). I'm trying to reduce energy costs w/out a lot of $$ in additional equipment, so I'm considering this retrofit idea by building the shroud for both intake fin sections and precolling with evaporation.
Why not just use the evaporative meida and a pump and let the condenser fan do the rest?
You can probably drop the temp to about 5 degrees above the dewpoint. One concern would be reducing the airflow significantly. The fan is designed for open air, no restriction or friction loss. I know in the late 70's this approch was tried by some companies and it resulted in lawsuits. Increased maintenance would also be required.
I did see a spray system on one of the DIY chanels.
Back in the 1980s we used to install a lot of these. Yes, they do slow the air down some, but they gain enough by the lowered entering temp that the net gain is significant. I'd like to give you the brand name, but I think that's against the rules. We did find them rather high maintenance.
Thanks
Mike
Never stop learning.
I saw a new system this week that attaches to a rooftop unit with magnets, covering the condenser coil. It has a wet pad with spray heads and a dry prefilter. The theory is the water evaporates from the wet pad providing the latent heat of vaporization, but does not destroy the condenser coil with contaminants from the water. Lots of added maintenance. Time will tell.
I'm a big fan of water cooled equipment and evaporative condencers. There is an evaporative condensing unit made in Ft Worth that would be my choice behind geothermal. The old redwood atmospheric cooling tower out in the alley was very efficient if you didn't mind the mess.