Sun Shades on Air Conditioning is worthless - Part I

[Xringer]

I have a small roof over my Sanyo mini-split. It's does cooling and heating. The roof keeps snow and ice from covering the coil ( & air input).

There is no air flow restriction. After my house is at setpoint, the Sanyo uses very little power to keep us cool. My Plasma TV uses more kwh.

The installation manual says NOT to install the unit in sunny areas, if there is a shaded area available.

Direct sun light on the unit does seem to help during the heating season. It defrosts faster too.

[turtlemann14]

shading does help for start up as long as it can get plenty of air also fine mist would help as well but, may cause it to clog up (from dust the water traps)

[turtlemann14]

shading does help as long as it can get plenty of air also fine mist would help as well but, may cause it to clog up (from dust the water traps)

[skarpes]

Yeah, that is "ridiculous"....(as is your spelling!)

[hackfreehvac]

@skarpes

Wow, you found a grammar mistake I didn't catch before encoding the video.

That changes everything.

Unless you were just kidding. Hard to tell.

[fixinggrace]

I had one brain surgeon who built a wooden roof over his A/C condensor to "protect" it from falling ice. It caused a leak at the service valves.

[hackfreehvac]

@fixinggrace

Gotta love the engineers, but a brain surgeon? LOL!

[michaelmerritt45]

seen worse unit 2' from 6 dryers outlet had screen around coil matiance man made it and washed it weekly 3 poped caps later moved the unit. You can tell some people something till blue in face.But they are smarter than tech .

[9020powrmax]

Been better to plant a BIG shade tree on the roof!! LOL!

[amit85]

what if you place a patio umbrella next to the air conditioner? it should be high enough off the ground to let air flow but still protect it.

[rtdem]

only a jacka** would mount a ac on a roof top; az = millions residential roof top ac unit. shading a unit is good science. shade keeps the whole unit cooler the cooler the entire unit the more efficient it will cool the air. You are correct that any "shaded air" wll b used up quickly; shaded air is not the point. keeping the temp of the entire unit to minimum is the point

[JuryDutySummons]

The sun can dump a considerable amount of energy onto a small area. Reducing the amount of energy being contributed by the sun from entering in the system is sound science... It would be interesting to see the efficiency gains from shade on the AC.

Loss of airflow on the other hand... well, that's gonna kill any gains 10 times over.

[wolfofworld]

Maby the home owner went to RSI.

[hyvahyva]

HA! I love that... the Ruud doesn't even let the sun shine on the coils in the first place due to the way the casing is built, so it's just completely ridiculous.

My grotty old Lennox lets the sun hit the black aluminum coils. It doesn't seem to affect it at all.

[darkmaster388]

Actually it does make a difference, however the difference usually way to slim....it's not cost effective.

That's why you don't get a new air conditioner with a sun shade from the manufacturer.

[jpjnet]

Anyone have anything to say about direct solar gain to the exterior air handler section of the unit(s)? This is the real reason to shade them, (without restricting air flow of course) not lowering the surrounding ambient air temperature. Measurable efficiency gains are not negligible in my book.

[eggman9713]

Or you could just use a split system like 99% of the homes up here.

[pabbananna]

please help me understand as I have a window AC unit in 100% sun all day. If you could make a shade that didnt restrict airflow (like a shade on a gooseneck way above the coils) would it not help? We have a 5500btu unit and it doesn't get cold at all. Any tips? How about putting a small 12v computer fan on the coils to help with air circulation?

[birdhunter317]

Ah, ruud,rheem or weatherking unit

[PutSome5tankOnIt]

'Shading' an AC with shrubbery is not the worst idea, as long as the plants are at least 12" away from the unit. Natural hedges and such reduce the ambient air temperature around a condensing unit. They also act as a buffer to absorb sound.

RTUs don't benefit so much from sunscreens. Most of these tend to restrict air flow into, and out of, package units.

Homeowners should reduce heat/sun gain on the entire home, before blaming the AC system.

[Mal3volution]

I agree; *those* shades aren't doing a bit of good, because they're restricting airflow. One that does NOT restrict airflow will help.

[hackfreehvac]

I don't even think shade from a small sun screen will do any good even if it DIDN'T restrict air. Just think, 5 seconds after start up, all the "shaded air" is all used up and it's just drawing in air from it's surroundings anyway! LOL!

[TheBrassHole]

I agree with you, and I think the people doing this to these units in the video are morons. The one thing I have found though, is that when units are in full sun, the metal housing is so hot you cant even touch it. But I agree the best thing you can do is keep your coils clean and check refirdgerant. nice vid. 5 stars.

[joestanton1962]

The fact of the matter is that if you have large ductwork (I have a double 90') then if you can shade the duct itself you will avoid the 20 or so cubic feet inside the duct (in my case) from heating up to 130' or so, which is then the first bit of air forced into the house. So if you can reduce that heat to 90 or so maybe you are doing some real good.

[TheBrassHole]

Damn that's good thinking man. I was thinking maybe planting trees around that area as well. So it would be shade but nothing obstructing the intake on the unit? I don't know, what do you think?  Is there a way I could cool down the ducts in my attic? This neighbor hood has no trees at all !!!! But it could take years for my roof to be shaded. :(

[DTownzz]

@hackfreehvac

Wrong, Hack free, it leads to about 5% power savings. And it's not like you 'suck up all the shaded air'. Planting a tree that shades your A/C will pay for itself quickly. Restricting airflow is extremely stupid, but a shade that doesn't do that can be more attractive than just a metal box and it can really make a dent in a power bill.

[hemiownzu]

I bet your head pressure was nice and high. Did it set the relief valve off or overload the compressor?

[hackfreehvac]

That one unit was a Carrier 50YQ or 50QQ and seem almost indestructable and is 5 times as dependable as a NEW Carrier! :p It wasn't high enough to trip off on IP. But did cause higher pressure which equated more energy used. The other unit was a neighbor to one of my customers. I never got to see what it actually did, but I talked to the owner of that unit when he came over to talk to my customer. He was so proud of that sun shade!

[REWYRED]

I helped a friend out that had a bad start cap in his A/C unit, too bad the previous owner of the place planted shrubs tight against the unit to shade and block the appearance of the condenser unit and servicing it was an absolute nightmare! Stupid people I tell ya! (Yes, I installed the new cap properly)! LOL

[hackfreehvac]

LOL cool. It's funny how they think the shrubs will help it. Usually the air restriction makes it worse. Not too mention the service access is crap!

[DTownzz]

@REWYRED

Yeah, that sounds really stupid. Just putting them a couple feet away would have worked much better.

[25HNA6]

When it is very hot outside, I like to wet down the coils with hose water on my heat pump while it is running.

[hackfreehvac]

The water will surely drop the temperature. The only BAD thing about that is depending on the mineral content of the water, it can load up the fins with scale, then reduce air flow. There are a few pictures shown from other techs from coils that had water sprayed on them on a regular basis. If it wasn't for the hard minerals in the tap water, I'd use misters controlled my coil temp to spray my own coil.

[itscool1968]

i do have to admit some of the attempts are down right strange and do nothing but make the unit work harder.

[hackfreehvac]

Exactly.

[worldlinerai]

I once saw on TV about energy saving tips that shading air conditioners from the sun increases efficiency. No explanation why.

[hackfreehvac]

If the entire AREA was shaded, like I mean the entire side of a building without restricting air flow in and out of the air conditioner, you MAY notice a drop in temperature compared to unshaded. However a shade simply errected around the unit like shown will not do jack sh*t. Because once the fan starts and moves all that air in and out, the small amount of shade wont mean anything and the entering air will be the same as what is in direct sunlight anyway.

[killtheglory]

i felt bad one day i had to explain to a customer how dumb spending 5 grand on a marble cover for her 2 condensers was a bad idea. thanks for the site. shows a lot of crap a lot of techs go through on a daily basis.

[hackfreehvac]

No Problem. Glad people appreciate it. :)

These marble covers. Did they cover the fan section? And did she remove them when it was in operation?

[killtheglory]

oh yea it was directly covering the fan section. it was a nice cover but the wrong place.

[mechanicwarrior20]

Well thats a common problem with some people they are just not educated enough about the principles of heat transfer and including common sense!!! But then again can you blame them?

[hackfreehvac]

I guess so. But it's pretty funny. Especially the guy with the Rheem that he went through all that effort to shade which is going to do more harm than good! Then he had all that exposed ductwork on his other side of his home! I think he should have put some effort into that system! I bet it pickes up several degrees of heat running through that round duct above the rooftop in the 120 degree summer!

[mechanicwarrior20]

Owe yeah efficiency what efficiency? LMAO seems a little like dehumidification if you ask me?...

[hackfreehvac]

Dehumidification? You refering to his second RTU that adds the heat back to the supply dict by time it gets to the supply grills? LOL!

[mechanicwarrior20]

Yuppers