Shielding an A/C Compressor/Condenser Unit

[Wayne Boatwright]

Our A/C Compressor/Condenser is only shaded by the shadow of our house until about mid-morning. The rest of the day it sits in direct sunlight. We live in the AZ desert where our summer temperatures are typically 110°F and above by early afternoon.

Natural shade from trees or shrubs are not a practical solution, both due to the location of the unit and the time it would take for the plants to grow to a useful size.

I would like to construct something that would shield the unit from the intense sun, yet also provide adequate air flow for the unit. Air is drawn in through all 4 sides and exits through the top.

I would like to do this as economically as possible, but I don't even have a clue where to start.

All ideas welcome...

TIA

[Red Green]

Wayne Boatwright wrote in news:Xns9C5899982DB28wayneboatwrightatari@69.16.185.250:

How about putting a lattice enclosure around it on 2 or 3 sides?

You can get lattice sheets and construct something to your liking or you can get sections or fencing with lattice. Not sure about the sections type but I've see a very dense lattice in sheets at Lowes.

Go to Lowes webside and search Lattice for some ideas.

Of course when the sun is directly overhead it's still an issue but possibly can minimize with lattice.

Keep in mind to construct it so the HVAC service people can get at it easily. Consider somewhat removable panel(s) by using screws in key access areas or maybe hinges.

Just some initial thoughts...

[ilbebauck]

982DB28wayneboatwrightatari@69.16.185.250:

BINGO on the lattice suggestion ; it will be the lowest cost solution, easy to assemble and install, and effective . Dont put it too close to the condensor coils...leave at least 6 inches clearance. Make sure there is no obstruction on the a/c discharge ; most manufacturers suggest at least 8 ' . If youre interested in getting a bit more capacity out of your a/c unit during scorcher days and at the same time drop the amp draw of the unit...consider spraying a fine mist of water over as much of the condensor coil area as practical ; but run the water thru an inline filter so you dont get alot of sediment and scale buildup on the condensor. If you go online, you can find ready-made systems that you simply hang on the side of the a/ c unit and water sprays out thru small holes in tubing. It really works good in hot and dry climates as you get evaporative cooling of the air air entering the condensor coils in addition to cooling of the freon in the tubes directly from conduction. Just use an inline water filter if you choose to go this route. Good luck.

[Wayne Boatwright]

On Thu 30 Jul 2009 03:56:03p, Red Green told us...

I think that's an excellent idea, especially joining the panels with hinges. We also get very strong winds, and as the unit sits rather close to the exterior house wall, I could also hinge it to the house on one side and and possibly eye hooks or something similar on the other side, maing the unit easily accessible for service. Attaching a piece across the top would certainly help, too. I would definitely allow ample space between the lattice and the unit itself for adequate air movement.

Thanks for a great idea!

[Stormin Mormon]

Dunno how this would look. Some kind of a frame with mylar space blanket. Reflect the sun. Or, you could get a portable clothesline, and hang a couple of bedsheets all the time. They also make dining canopy, but that would tend to keep the heat in.

Spraying water on the coils, that's likely to leave minerals which will eat away the coil.

The portable clothes line might be tacky looking, like leaving the plastic wrap on your table lamps. But it could help.

[harry k]

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There have been threads in the past on shading a compressor/ condenser. Altho it seems to go against common sense it seems that there is no benefit to doing it. The compressor works on the air passing through it, not on the ambient conditions around it. Might be some gain on initial start up but not after that.

Harry K

[Tony Hwang]

Hmmm, Patio umbrella.

[Wayne Boatwright]

On Thu 30 Jul 2009 08:47:21p, Tony Hwang told us...

Probably a good idea in some areas, but we've lost 3 to the high winds just this summer. :-)

[Red Green]

harry k wrote in news: [e-mail]:

Dunno Harry. Wayne wanted to do something and I just tossed my .02 at it. Leave the deeper logistic on this one to r&d :-)

[Wayne Boatwright]

On Thu 30 Jul 2009 08:40:59p, harry k told us...

Perhaps, although one would think that if temperatures measured in both full shade and full sun vary by as much as 8-10 degrees in adjacent areas, that it would lighten the load on the unit if it were shaded.

[Stormin Mormon]

I read a couple years ago. About a study of this, using two identical houses. Condensor on sun or shade side. They did conclude not enough difference. Still, my experience tells me that things in the sunshine are hotter. And, that's got to make some difference.

I hope Wayne has an AC service company chemically clean the outdoor unit. That will make much more difference than shading.

[sligoNoSPAMjoe]

Yea it would be good to sheld the unit from the sun, but likey not as much good as you might think. Partly because anything you provide is likely to also block air circulation and because it really does not add as much to the heat load as you might think.

The A/C unit is likely light colored or metalic. It will tend ot reflect more heat than most serfaces of your home. It also is a very small area compared to the roof, walls and windows of your home.

My suggestion is to make some effort, but don't over do it and don't block air ciruclation or it will likely reduce overall efficency.

[Bob F]

That temp measured in sun is a static thing. Start moving air with a fan and it quickly disapates. The savings by shading the heat exchanger will be pretty small.

A louvered lid over the unit would probably be the best way to shade it if this is really wanted. Angle the louvers toward the north. The air passes through, the sun is stopped. The sides are open for full air flow.

[jamesgangnc]

[Dave]

I live in Phoenix and tried the water on the condenser trick and it did nothing to help with cooling, at least not on the inside of my house. My A/C unit ran just as long to cool the house and the air coming out of the vents was no cooler.

I saw no benefit and wasted precious water in the process.

My limited knowledge of how A/C condensers work tells me that the ambient temperature of the coils is not significant so long as the gas coming in on the inlet side is changed to liquid on the output side.

[Stormin Mormon]

High temps mean higher pressures, and higher amperage.

[Ed Pawlowski]

The water would make a difference in a marginal unit. Properly sized, the heat carrying ability of the system will take care of the house.

[Lp1331 1p1331]

Wetting the condenser has much less effect on newer high efficiency units than it did on typical units 25-30years ago, because the condenser coils on the newer ones are so much larger.I have seen new 1.5 ton units that were physically larger than antique 4 or even 5 ton units. I have checked the amp draw right after washing the condenser on numerous units, and left the amprobe on it until it dried and the system stabilized. The smaller the condenser coil is, usually the more the amperage goes up as it is drying. Recently did that on a fairly new 16 SEER, and there was very little differnce between wet and dry. This was on a day that was probably in the high 90s. Granted, when you get up in the 115+ range, the difference would be much larger. There are/were several "hybrid" units that are what amounts to a cross between a swamp cooler and a regular air cooled condenser, made mainly for the AZ area. Freus (sp?) is one. There was one called ACll or AZll or something like that, but I think they are no longer around. On them, they were really a swamp cooler, with a serpentine coil of copper tubing in the water trough that the Freon went through to be cooled . It was technically a water cooled condenser with a cooling tower. I think it was one of those things that looked good on paper, but---. Actually I heard they worked fairly well, but were maintainence nightmares This whole subject has been discussed in here several times over the years. There was research done by some outfit in Florida a while back (don't remember who/what it was) but their test result showed there was a very slight gain by shading, but it was not significant. Larry

[benick]

Asked the HVAC guys at the jobsite today and they chuckled and said it doesn't make a damn bit of difference...FWIW....

[Wayne Boatwright]

On Thu 30 Jul 2009 04:08:06p, [e-mail] told us...

innews:Xns9C5899

Thanks, yes I was thinking about 6" clearance from each side of the unit. Since the latice panels are usually 8' tall, I might just forego putting any top on it and depend on the height of the latice panels.

As to using a mist on the coils, unfortunately it would be very impractical here in AZ. We have some of the hardest water in the country where I live and without a water softener in addition to the filters, the mineral buildup would quickly clog the fins on the coils.