Should I shade my outdoor air conditioner unit to lower my electric bill or cause the compressor to work less?

Question

Somewhere I heard that if you erect some sort of "shade" over your unit without restricting air flow, it can help with your electric usage by causing the compressor not to work as hard. I know that keeping the fins flushed out does help and I flush them out about 4 times a year. I keep the grass and other plants away from the unit, however, there is nothing to give it any shade. I live in Corpus Christi, TX and we have high heat as well as high humidity. I have done everything to the inside of the house to prevent air loss. Now I am checkout outside. With the exception of a NEW unit, what do you think? Thank you for your time and consideration in answering this question.

Answer 1

I have been affiliated with most of the manufacturers as contractor, wholesaler and manufacturer's tech rep over the last 48 years.  It's pretty much universal that any condenser that discharges it's air upward has a minimum overhead clearance of 60 inches.  Even that may cause hot discharge air to re-circulate back into the unit.  This will cause the system operating pressures to be abnormally high, the compressor will be forced to work harder against these higher pressures, and it will cost more electricity $, not to mention that you'll shorten the life of the compressor and need to replace it a lot sooner.

It sounds like you're doing the right things; don't try to push your indoor temperature more than 20 degrees below outdoor temps.  Going from 68 inside to 95 outside can literally knock you off your feet, especially if you forget something, run back in, then out again.  Rapid temp changes in a short space of time can cause dizziness and nausea (been there).  Keep the indoor and outdoor coils clean, block any air leaks in the ductwork joints, use a programmable t/stat for set-back in summer and winter.  So long as you control the humidity, the indoor temp can be higher in summer and lower in winter, and still feel comfortable.

Answer 2

I agree with Mark the improvement would be minimal because you would only be cooling the houseing.But it should help some if the unit is on a roof or the SW side of the house.Years ago some one sold a water mister to do the same thing but You don't hear about them any more (probably because of high water cost/mold/calcium etc)

Answer 3

I have actually tested this theory. This was on a window unit though. I had a window unit in a window that would not cool the room. The air coming out was just slightly cool. The unit was in the afternoon sun. I decide to see if the sun was too much for the unit, so I tried a test. I hung a piece of wood about 2 feet in front of the unit to block the sun. It worked. The air coming out of the unit dropped to a much colder temp. Here's the catch. As the previous person mentioned, you can not put something too close to the unit. It will not be able to breath and you will defeat the purpose. You want the shrub or screen as far away as possible, but still block the direct sun. Don't put something closer than a couple of feet.The unit must be able to circulate air around it's self and If you plant a shrub, make sure you keep it trimmed well away from the unit. I use Rose of Sharron. It's very fast growing, loves the sun and can be cut back regularly without harming the bush. Once established, the Rose of Sharron grows 3 ft a year in Missouri.

Answer 4

Well, I have been in this field for a long time. And there have been several debates on if the shade helps the unit or does not help the unit. Honestly, I feel that it would be such a minimal affect on the outdoor system will help lower your elec. bills. Some things that can help lower your elec. bill are set your t-stat a few degrees higher, as long as you dont constantly shut the unit off and on, the humidity will diminish. a 75 inside temp with a 95 outside and 70% humidity will keep your  house comfortable, also keep that filter clean....that is the biggest issue we run into. But do not I repeat do not cover the outdoor unit over the top within 3' foot, this will cause the unit to work much harder and that will cause your unit to increase demand on your elec. bill.