If you shade it with some large canopy trees that actually reduce the ambient of your back yard, it would do the trick. Try planting some trees and get back with us in 70 or 80 years with the results.
I have two cents to throw in. I understand the comments AD made about the surrounding radiant heat which is no doubt a factor. However, when you have a unit in direct sun, the metal is going to get very hot and stay hot. So, it seems you have kind of like a mini solar oven encasing the coils. That has to be a factor, too. So, if you can shade the unit in such a way that you are not retaining warm air around the unit, and can keep that metal cooler, it seems to me it has to help the coils exchange heat at least a little.
I *wanted* to believe this same concept, but found out that due to the MASSIVE amount of cuFt per minute air flow there just isn't enough time for the incoming air to be warmed up by the small mass of sun-heated steel in the case. Sure, there is SOME heat gained, but it is infinitesimal. A typical unit moves 170,000 cu ft of air per hour- that's a TON of air moving past the aluminum (?) shell.
For those looking for practical solutions on a HOT day - You have to cool the ambient temperature surrounding the AC unit, and not the unit itself. Here's a working example: Our AC is in direct sunlight. During the 1st HOT day (100+ degrees and insanely humid) of the Jun 2022 heat wave we made the mistake of leaving all of our indoor electronics on, and I even opened the door going into the garage (from the house) so I could keep it cool while I worked out there (which I do regularly). BIG MISTAKE on that day! The indoor temps quickly rose to around 80+ degrees, and the AC unit ran continuously for a couple of hours without making any kind of dent whatsoever. After doing some research I learned a fast solution to my problem - Water the area around the AC unit (NOT THE UNIT ITSELF, or you will corrode it) to reduce the ambient temperature around the unit. Our AC unit is surrounded by mulch, and so I soaked the mulch using the garden hose. I also sprayed down the area of the fence that is 3-10 feet away from it. The unit was still in the sun, and the outdoor temps hadn't changed any, however the temperature in the house immediately started dropping to our set temperature of 74 degrees (It took maybe 20-30 minutes to get there, but each 1-degree drop felt AMAZING). We continued to spray every hour or so, merely as a precaution to help get us through the rest of that particular day, but the AC was QUICKLY able to return to it's normal operation, kicking on and off only when it needed to. In short - You can try to cool the 'AC unit' all you want, but it doesn't change the fact that you are still using the surrounding HOT air to cool with. But with the sun hitting the watered mulch, vaporizing the water, it reduces the ambient temperature that gets sucked into the AC unit, allowing it to do it's job more efficiently.
Nice experiment. I’ve always wondered this. I think most of us who are interested in shading our units would look to adding shrubbery or small trees around our units to help but another factor you have to deal with is increased debris on the units which is a bigger detriment to performance than what you may gain from shading, judging by your vid. Guess I’ll leave my unit clear of any greenery. Thanks!
Ever lean up against the hood of your car in the summer time? Sun heats the metal on the AC. Air drawn over that hot metal heats up. Also, conduction of that heat will eventually reach the coils to some degree. Best place to install the outside unit is on the north side of the house and next best place on the east side. Even a 5 degree increase in air temperature can make a difference. Ever notice that things are cooler in the shade? Ever try to find a parking spot under a tree? Why is that?
1. The unit is actually already shaded...by the metal casing which does not transfer significant amounts of heat into the aluminum/copper lines and compressor down inside. 2. The key efficiency of the unit itself has to do with how well it transfers heat out the top, not how hot the unit is. 3. The only worthwhile external aid to supplement efficiency is lowering the ambient outdoor air temp around the unit. You need to cool the air itself being pulled through the unit. To do that passively requires putting the entire side of the building in shade. You can do it actively, for example when you have a house full of guests and the AC is barely getting things done, by misting a large area around the unit. This isn't something you want to do regularly as city water affects metal/patinas cooling fins much more aggressively than rainwater.
Was thinking of shading my outside unit, but after watching your video decided not to. It seems that not building a shade will save me more money in materials than shading would have in electricity. Excellent video. Thank You...
I am glad to see this, I use to have an evaporative cooler and I believe that shading those does help as your water is cooler VS sun. AC as you mentioned is about the BTUs and operating efficiency not being effected by full sun.
Shade might have more impact on a unit without the sheet metal louvers which are already shading the coil. If you had a test unit with the guards made from welded round bar, it would be interesting to see if it made a difference.
I noticed this as well. In your test, I'm not sure the sun gets down to heat the actual coils. In my units, I do not have the louvers. Thanks for your time and effort looking into this issue.
Thank you. I was going to do all kinds of construction to shade my outdoor gas pack. But now I see the money I would have spent would outweigh any benefit to the operation of the unit...👍
I have a 7' by 9' shade sail sitting over my AC condenser unit, suspended horizontally between four steel shepherd hooks. I initially positioned the shade sail to rest on the top of the condenser (with the unit off), then cut out a hole just slightly larger than the diameter of the circular discharge channel. While I have no objective data to report, I can definitively say that 1) the discharge air is noticeably warmer after providing full shade to the unit 2) the run time is significantly reduced. I also noticed that the concrete slab that the unit is sitting on is considerably cooler. Finally, I can say that my overall energy usage (measured in KwH) is lower this month than it was at the same time last year, despite the fact that temperatures are much warmer this year.
When I have customers that state power usage is higher/lower than normal, I just have to sigh. There are far too many variables. From what you say about the increase in discharge temp, I would have to say you have made a change that has made the unit less efficient. If you were reducing the load on the A/C unit , the discharge air would be lower, not higher. Not trying to beat you up, A/C just does not work that way. GFM
@@grayfurnaceman I agree, there's too many variables. But I think your own work misses a lot of variables as well. In particular, it seems like you are getting 'snapshot data', only looking at minutes or maybe hours. And it looks like you're making guesstimate averages off your instruments, which are showing pretty choppy data. You need to look at full days, at the minimum. I'd love to see: - a multi-day run, measuring the total power usage at the AC - with (and then without) the biggest sun shield you can make for $100 - with (and then without) misting nozzles located every 4 feet around the perimeter of said sun shield I don't have data, but I think that combination would be worthwhile for many people. Better where the humidity is low and the water isn't brine, for sure. Are you in the Spokane area? You should have pretty low humidity.
@@darrenstensland5301 On the multi day run, you might, emphasis on "might" be able to get good numbers in some of the Southwest states in high summer, but here, not a chance. Again, too many variables. I think you are concentrating in the wrong area. Insulation, attic fans, shading windows are all methods that will have far more effect. I will be doing a revisit on the misting issue in the near future, as we have a heat wave going on here in Spokane. GFM
My conditions are the 4 ton heat pump is on the roof in 120F in the shade/140+ on the metal of the unit in direct sun. Shading the unit has a much bigger effect in these conditions I am sure. I built a shade by cutting a circle in a square of plywood the same as the fan outlet and bolted it on using the hold down screws that suspend the fan grill. This isolates the air from the sides so they cant suck hot discharge from the fan. The plywood overhangs the unit all the way around so Sun can't hit the unit directly after about 9 am all the way to Sunset. You can feel the evaporative fins are way cooler than when in full sun.
Your test is flawed, you have to wait until surrounding heat up and cool down.Shading the entire area 10' will cool down radiant heating up building, ground etc. It takes time for things to heat up and cool off. The radiant heat will heat things up and thus higher highside but it's not huge. Take reading same time of day on different days with no clouds. The tarp needs to be in place the night before, then next cloudless day, no tarp from sun up.
The problem with your method is there are no 2 days the same. The only way to have the same temp and radiant heat is to use the same day. Not only the same day, but the same time as close as possible. In my opinion, any radiant heat is dissipated quite rapidly. Also, any heated air will rise and not be part of the issue. Your comment is appreciated but we will just have to disagree. GFM
The EPA study goes on to state, “Field measurements have shown that through shading, trees and shrubs strategically planted next to buildings can reduce summer air conditioning costs typically by 15 to 35 percent, and by as much as 5 percent or more in certain specific situations. Simply shading the air conditioner-by using shrubs or a vine-covered trellis-can save up to 10 percent in annual cooling-energy costs.” You guys don't understand radiant heat. Stand on roof in full sun vs your lawn. It heats up surrounding area so higher highside. Moving a tarp up and down is not the same.
That would be the ultimate test as that's what really matters. I insulated an exhaust vent pipe which runs through my garage and the air temperature coming out increased two degrees which is pretty significant.
Awesome test! Obviously it wouldn't be practical to test this, but approximately how much of a difference would it make to run refrigerant lines through a hot attic vs a comparatively cool crawlspace? Sometimes there isn't an option, but would it matter? Thanks
I had my unit place on the side of the house where it would only get sun from morning until about 2pm. Then the house itself shades the unit during the hottest part of the day.
I think you'd need to shade an area larger than just the unit. The point would be to reduce heat gain in the thermal mass surrounding the A/C unit. In your case, the fact that the surrounding area is grass probably helps more than anything else. Desert landscaping might benefit more from shading than would grass lawns.
The point of the video is shading of the unit is of little value. Certainly if you shaded the entire side of the structure, there would be a small difference in air temp around the unit. But the efficiency increase is in the low single digits. GFM
@@grayfurnaceman Based on what you also came up with in your mist/sprinkler tests, that seems to be pretty certainly the case. You'd probably have to do all day tests and then account for daily temperature changes to know what the real practical difference is. All told it comes down to the total number of BTUs the sun might add, and that is surely a small fraction of the total BTUs involved. Thanks for doing the testing.
I am curious about a couple of things. While the pressure may be close... is there any difference in the electrical amp draw? Other question I have is when was the condenser thoroughly cleaned? A dirty condenser will always have same problem regardless of any shade/sun, wtc… the coil could not work efficiently regardless. Clean the condenser twice (both indeoor and outdoor coils) and I think threse two questions would resolve this debate. Thanks!
The reason I am asking is because I remembered having a contractor change out a condenser for a friend. The old condenser and new is same two ton. The old and the new unit is roughly the same SEER 9 and 10 but they are like 25 years difference. The old one was pulling nearly 19 amp power draw and the new one pulled only 9 amp. They were both R-22 unit. This was an interesting observation.
thought experiment: could putting an air-source heat pump condenser in an underground bunker (fruit cellar?) make it viable more often as a primary heating source in cold weather? could the cost of building and operating a bunker system be cheaper per btu than a ground source system? could a solar panel array with storage power this?
I have lived in the high desert of Ca, and it does appear that the sun is different there. However, it is mostly an illusion. Temperature is not BTUs GFM
Its all about BTUs, Radiant heat from the sun can certainly make you feel warm (at least on one side), but does it add a large amount of BTUs? My contention is that the area warmed is too small to be of consequence. GFM
Like the experient. I am using the airco much more for heating than cooling (i live higher north i guess). When the airco was installed it was put on the North side of the house so its always in the shade. So I was wandering if putting the airco in the sun would make a difference with heating the house. Looking at your experiment, probably not. It might help a bit if the sun hits a larger area and the airco sucks in the air over that area (e.g. flat part of the roof).
My condenser was directly exposed to the sun (Coleman brand). I ziptied some louver vent / return air grill in front of the fins which inhibits the air minimally but blocks the sun when oriented downwards. My temperature from supply vents at the second floor with air infinity booster fans dropped from minimum of 60 degrees to minimum 56-58 degrees. I think the sun exposure factor is minimal unless your fins/coils are exposed and get heated up by the sun.
There are far too many variables here to make any judgement. Condenser fans work on very small air pressures. Any blockage can be important. Reduction in air temp could be due to an increase in head pressure from the louvre installation. In any case, take the junk off the condenser and let it breathe. GFM
try doing this experiment in Phoenix where the July temperature is around 115 deg daily - i have been keeping my a/c under a cantilever umbrella for several years (the umbrella is like 5 feet above the a/c unit so does not block the air flow) - without the umbrella you cannot even touch the housing on the a/c - with the umbrella you can - i think shading it in places like Phoenix absolutely help the unit (don't have numbers like you had)
I also have lived in desert areas (high desert in Ca). Nothing metal set in the sun could be touched. However, temperature is not heat volume (BTU). The amount of heat is very low. 10# of sheet steel using a specific heat of .120 BTU per # raised from 100 to 180F equals 90 BTU. A 5 ton A/C is 60,000 BTU. GFM
@@grayfurnaceman that's good info and thanks (the umbrella probably does nothing then other than make me feel better haha - i do keep it up high to not block the air venting out of the top of the unit) - i am not an a/c repairman (do have a background in electronics though) - it is pretty interesting (been watching numerous videos on how the techs measure various areas which catches my attention - still learning the terms) - one thing i also don't do is run my a/c that hard - only 80 degs during the day (79 at night) - i know a lot of folks run them at like 67 which i feel is too hard on the unit and shortens their life (i want the unit cycling on/off - not running constantly)
@@tonybaker8971 I have never understood the tendency to set the temp well below what you would want to have it in the winter. And anything lower than 70F you run the risk of freezing the evap coil. GFM
HELP ME Understand. Not much of an A/C guy, however, in the heat the supply inside was 59degrees and the return was 78degrees. But in the shade, the supply was 55 degrees and the return 74 degrees. That tells me the a/c in the house is colder in the shade and it will not take long to cool down, thus saving you money in electricity. Am I interpreting this correctly? Yes the Head pressure is the same, but if the air is colder then the A/C will not be on as long. Is this true?
The temp variations inside the structure are dependent the actual load. Not the performance of the air conditioner. What we are testing here is the performance of the air conditioner. The performance of the air conditioner is exhibited by temp drop across the indoor coil. The return air temp has nothing to do with performance of the air conditioner. GFM
Well this is good to know. We have two units at this 2016 house on the side that gets a lot of sun during the day. But the discharge air is actually not that hot at all (if that means anything).
I'm not an AC professional, but I don't understand how measuring the pressures are an effective way to quantify the actual benefit. Where the rubber meets the road would be to determine if there is an increase in cooling output and decreased up time. If the condenser is cooler, then I'd presume heat can be more readily expelled and the AC may not need to run as long. And if it is a package unit, the air flowing through the unit can be more effectively insulated from the exterior heat if it is shaded.
I am an A/C professional and how you determine if, it fact, you have reduced BTUs is by the head pressure of the unit. Higher BTUs that the unit must move, equals higher energy use. GFM
@@yournightmareracing1754 Variations in return temp are common throughout the day and during the on and off cycle. When the unit starts, return tends to be higher than at the end of the cycle. If there is no difference in temp drop, there is no difference performance. GFM
the answer is dont add shade with the hopes of energy savings. but if a shaded area is available during installation go ahead and place condenser there to make a miniscule change that may become $50 savings over 20yrs. lol
@@grayfurnacemanI believe heartcharm says that due to your readings of supply and return air. On your video it shows it being cooler when it is shaded. So wouldnt colder air going into your home reduce the A/C from being on the whole time thus saving you money?
@@JD-gm9op In a word, no. The difference in return air temp is a difference in load, not performance of the outdoor unit. Load changes constantly, so return air temps change. GFM
I just want to make a comment, it's not really a criticism but may appear so. But in all these tests you are running I think are starting out biased because your system is already operating at peak performance. The misting , the shading, these things to know if they work, need to be tested on AC units that are not already working at peak performance. I don't use any of them, but I know for an absolute fact I have seen on commercial units where maintenance people will literally run a hose of water on the unit to improve the performance on a really hot day. So I would have to assume that while it's not practical, clearly it provides a benefit in certain conditions. I would gather shading may potentially also provide some benefit. I really like your channel though. I have done a lot of proof of concepts in IT so I definitely understand testing equipment. You can't improve upon something unless it's operating under a certain threshold.
You are right. A properly operating air conditioner cannot be improved upon. If you were using an A/C from the 1970s, you may be able to improve its operation. GFM
I would think that shade and or water would only show a benefit with temps over 100 degrees, I have an older big widow unit that is shaded but when Texas summers get over 100 with low humidity it will almost quit cooling, I only have to spray it down once and not a lot to make it happy.
In AZ in my development Concrete walls are built FOOT around the Condensers leaving only a foot space. ( one side open). Keeps out the sun except on the top. This video puts that to rest.
Dude, your answer is in the beginning, you had the head pressure at around 350PSI then when the sun was on it to was around 430PSI.... Your answer is the appropriate shading dose help.... Also you should also wait about 1/2 an hour to an hour...
@@grayfurnaceman that's what the shade is suppose to reduce..... Everyone knows if its a hot day you don't sit in the sun, you sit under the shade.... Same applys to your ac :)
If you shade it with some large canopy trees that actually reduce the ambient of your back yard, it would do the trick. Try planting some trees and get back with us in 70 or 80 years with the results.
LOL
COMEDIAN
Lol what a joke. shading doesn't do anything.
Actually discharge pressure is slow the it's works mini split ac work
Carl McCoy lol. He might be 6 feet under by then.
Yeah I think you need to cool the air going in not just the unit. Air condition your air conditioner.😁😁💕🎆
I love that you take on these questions that many of us wonder about but don't really test.
I have two cents to throw in. I understand the comments AD made about the surrounding radiant heat which is no doubt a factor. However, when you have a unit in direct sun, the metal is going to get very hot and stay hot. So, it seems you have kind of like a mini solar oven encasing the coils. That has to be a factor, too. So, if you can shade the unit in such a way that you are not retaining warm air around the unit, and can keep that metal cooler, it seems to me it has to help the coils exchange heat at least a little.
I *wanted* to believe this same concept, but found out that due to the MASSIVE amount of cuFt per minute air flow there just isn't enough time for the incoming air to be warmed up by the small mass of sun-heated steel in the case. Sure, there is SOME heat gained, but it is infinitesimal. A typical unit moves 170,000 cu ft of air per hour- that's a TON of air moving past the aluminum (?) shell.
For those looking for practical solutions on a HOT day - You have to cool the ambient temperature surrounding the AC unit, and not the unit itself.
Here's a working example: Our AC is in direct sunlight. During the 1st HOT day (100+ degrees and insanely humid) of the Jun 2022 heat wave we made the mistake of leaving all of our indoor electronics on, and I even opened the door going into the garage (from the house) so I could keep it cool while I worked out there (which I do regularly). BIG MISTAKE on that day! The indoor temps quickly rose to around 80+ degrees, and the AC unit ran continuously for a couple of hours without making any kind of dent whatsoever.
After doing some research I learned a fast solution to my problem - Water the area around the AC unit (NOT THE UNIT ITSELF, or you will corrode it) to reduce the ambient temperature around the unit. Our AC unit is surrounded by mulch, and so I soaked the mulch using the garden hose. I also sprayed down the area of the fence that is 3-10 feet away from it. The unit was still in the sun, and the outdoor temps hadn't changed any, however the temperature in the house immediately started dropping to our set temperature of 74 degrees (It took maybe 20-30 minutes to get there, but each 1-degree drop felt AMAZING). We continued to spray every hour or so, merely as a precaution to help get us through the rest of that particular day, but the AC was QUICKLY able to return to it's normal operation, kicking on and off only when it needed to.
In short - You can try to cool the 'AC unit' all you want, but it doesn't change the fact that you are still using the surrounding HOT air to cool with. But with the sun hitting the watered mulch, vaporizing the water, it reduces the ambient temperature that gets sucked into the AC unit, allowing it to do it's job more efficiently.
Thank you for using science to determine the correct answer to this ongoing question. Your channel is very helpful.
Nice experiment. I’ve always wondered this. I think most of us who are interested in shading our units would look to adding shrubbery or small trees around our units to help but another factor you have to deal with is increased debris on the units which is a bigger detriment to performance than what you may gain from shading, judging by your vid. Guess I’ll leave my unit clear of any greenery. Thanks!
Ever lean up against the hood of your car in the summer time?
Sun heats the metal on the AC. Air drawn over that hot metal heats up.
Also, conduction of that heat will eventually reach the coils to some degree.
Best place to install the outside unit is on the north side of the house and next best place on the east side.
Even a 5 degree increase in air temperature can make a difference.
Ever notice that things are cooler in the shade?
Ever try to find a parking spot under a tree? Why is that?
1. The unit is actually already shaded...by the metal casing which does not transfer significant amounts of heat into the aluminum/copper lines and compressor down inside.
2. The key efficiency of the unit itself has to do with how well it transfers heat out the top, not how hot the unit is.
3. The only worthwhile external aid to supplement efficiency is lowering the ambient outdoor air temp around the unit. You need to cool the air itself being pulled through the unit. To do that passively requires putting the entire side of the building in shade. You can do it actively, for example when you have a house full of guests and the AC is barely getting things done, by misting a large area around the unit. This isn't something you want to do regularly as city water affects metal/patinas cooling fins much more aggressively than rainwater.
Was thinking of shading my outside unit, but after watching your video decided not to. It seems that not building a shade will save me more money in materials than shading would have in electricity. Excellent video. Thank You...
I am glad to see this, I use to have an evaporative cooler and I believe that shading those does help as your water is cooler VS sun. AC as you mentioned is about the BTUs and operating efficiency not being effected by full sun.
Shade might have more impact on a unit without the sheet metal louvers which are already shading the coil. If you had a test unit with the guards made from welded round bar, it would be interesting to see if it made a difference.
I noticed this as well. In your test, I'm not sure the sun gets down to heat the actual coils. In my units, I do not have the louvers.
Thanks for your time and effort looking into this issue.
Thank you. I was going to do all kinds of construction to shade my outdoor gas pack. But now I see the money I would have spent would outweigh any benefit to the operation of the unit...👍
Thanks for all you do. I have learned alot form your vids.👍👍
Welcome
GFM
Thanks for test. Agree.
I have a 7' by 9' shade sail sitting over my AC condenser unit, suspended horizontally between four steel shepherd hooks. I initially positioned the shade sail to rest on the top of the condenser (with the unit off), then cut out a hole just slightly larger than the diameter of the circular discharge channel. While I have no objective data to report, I can definitively say that 1) the discharge air is noticeably warmer after providing full shade to the unit 2) the run time is significantly reduced. I also noticed that the concrete slab that the unit is sitting on is considerably cooler. Finally, I can say that my overall energy usage (measured in KwH) is lower this month than it was at the same time last year, despite the fact that temperatures are much warmer this year.
When I have customers that state power usage is higher/lower than normal, I just have to sigh. There are far too many variables.
From what you say about the increase in discharge temp, I would have to say you have made a change that has made the unit less efficient. If you were reducing the load on the A/C unit , the discharge air would be lower, not higher.
Not trying to beat you up, A/C just does not work that way.
GFM
@@grayfurnaceman I agree, there's too many variables. But I think your own work misses a lot of variables as well. In particular, it seems like you are getting 'snapshot data', only looking at minutes or maybe hours. And it looks like you're making guesstimate averages off your instruments, which are showing pretty choppy data. You need to look at full days, at the minimum. I'd love to see:
- a multi-day run, measuring the total power usage at the AC
- with (and then without) the biggest sun shield you can make for $100
- with (and then without) misting nozzles located every 4 feet around the perimeter of said sun shield
I don't have data, but I think that combination would be worthwhile for many people. Better where the humidity is low and the water isn't brine, for sure. Are you in the Spokane area? You should have pretty low humidity.
@@darrenstensland5301 On the multi day run, you might, emphasis on "might" be able to get good numbers in some of the Southwest states in high summer, but here, not a chance. Again, too many variables.
I think you are concentrating in the wrong area. Insulation, attic fans, shading windows are all methods that will have far more effect.
I will be doing a revisit on the misting issue in the near future, as we have a heat wave going on here in Spokane.
GFM
My conditions are the 4 ton heat pump is on the roof in 120F in the shade/140+ on the metal of the unit in direct sun. Shading the unit has a much bigger effect in these conditions I am sure. I built a shade by cutting a circle in a square of plywood the same as the fan outlet and bolted it on using the hold down screws that suspend the fan grill. This isolates the air from the sides so they cant suck hot discharge from the fan. The plywood overhangs the unit all the way around so Sun can't hit the unit directly after about 9 am all the way to Sunset. You can feel the evaporative fins are way cooler than when in full sun.
It has to be none over a full day nay a matter minutes
Your test is flawed, you have to wait until surrounding heat up and cool down.Shading the entire area 10' will cool down radiant heating up building, ground etc. It takes time for things to heat up and cool off. The radiant heat will heat things up and thus higher highside but it's not huge. Take reading same time of day on different days with no clouds. The tarp needs to be in place the night before, then next cloudless day, no tarp from sun up.
The problem with your method is there are no 2 days the same. The only way to have the same temp and radiant heat is to use the same day. Not only the same day, but the same time as close as possible. In my opinion, any radiant heat is dissipated quite rapidly. Also, any heated air will rise and not be part of the issue. Your comment is appreciated but we will just have to disagree.
GFM
The EPA study goes on to state, “Field measurements have shown that through shading, trees and shrubs strategically planted next to buildings can reduce summer air conditioning costs typically by 15 to 35 percent, and by as much as 5 percent or more in certain specific situations. Simply shading the air conditioner-by using shrubs or a vine-covered trellis-can save up to 10 percent in annual cooling-energy costs.” You guys don't understand radiant heat. Stand on roof in full sun vs your lawn. It heats up surrounding area so higher highside. Moving a tarp up and down is not the same.
@@publicmail2 The EPA also claims 410A is a better, more efficient refrigerant than R22, and look how that has gone LOL
Video #3? Shade AC. Take inside vents blowing temperature. Then sun the AC and take vent temperature readings again.
That would be the ultimate test as that's what really matters. I insulated an exhaust vent pipe which runs through my garage and the air temperature coming out increased two degrees which is pretty significant.
Awesome test! Obviously it wouldn't be practical to test this, but approximately how much of a difference would it make to run refrigerant lines through a hot attic vs a comparatively cool crawlspace? Sometimes there isn't an option, but would it matter? Thanks
As the suction line is insulated and the liquid line is very small, I would think the difference would be small.
GFM
@@grayfurnaceman That's pretty much what I thought, thanks for confirming.
I had my unit place on the side of the house where it would only get sun from morning until about 2pm. Then the house itself shades the unit during the hottest part of the day.
I think you'd need to shade an area larger than just the unit. The point would be to reduce heat gain in the thermal mass surrounding the A/C unit. In your case, the fact that the surrounding area is grass probably helps more than anything else. Desert landscaping might benefit more from shading than would grass lawns.
The point of the video is shading of the unit is of little value. Certainly if you shaded the entire side of the structure, there would be a small difference in air temp around the unit. But the efficiency increase is in the low single digits.
GFM
@@grayfurnaceman Based on what you also came up with in your mist/sprinkler tests, that seems to be pretty certainly the case. You'd probably have to do all day tests and then account for daily temperature changes to know what the real practical difference is. All told it comes down to the total number of BTUs the sun might add, and that is surely a small fraction of the total BTUs involved. Thanks for doing the testing.
Thanks for taking the time to do this! I’ve always wondered and now I know!!
I am curious about a couple of things. While the pressure may be close... is there any difference in the electrical amp draw? Other question I have is when was the condenser thoroughly cleaned? A dirty condenser will always have same problem regardless of any shade/sun, wtc… the coil could not work efficiently regardless. Clean the condenser twice (both indeoor and outdoor coils) and I think threse two questions would resolve this debate. Thanks!
The reason I am asking is because I remembered having a contractor change out a condenser for a friend. The old condenser and new is same two ton. The old and the new unit is roughly the same SEER 9 and 10 but they are like 25 years difference. The old one was pulling nearly 19 amp power draw and the new one pulled only 9 amp. They were both R-22 unit. This was an interesting observation.
indoor coil? you mean inner coil?
Well, at least I don’t feel as bad now about the compressor being on the sunny side of the house.
Glad it helped.
GFM
thought experiment: could putting an air-source heat pump condenser in an underground bunker (fruit cellar?) make it viable more often as a primary heating source in cold weather? could the cost of building and operating a bunker system be cheaper per btu than a ground source system? could a solar panel array with storage power this?
Good grief, no. Not enough area. Not going to deal with the rest.
GFM
Thanks for your continued science...
I feel like shading the ac unit would do more where i live in the desert averages 120-130f for 3 months.
I have lived in the high desert of Ca, and it does appear that the sun is different there.
However, it is mostly an illusion. Temperature is not BTUs
GFM
What keeps you in such a hot place? That's withering heat.
@@darrenstensland5301 my wife's family, but recently i just moved back to Washington never going back hahaha.
This is very scientific, but I know from experience that I feel much cooler in the shade of a tree than I do out in full sun.
Its all about BTUs, Radiant heat from the sun can certainly make you feel warm (at least on one side), but does it add a large amount of BTUs? My contention is that the area warmed is too small to be of consequence.
GFM
Like the experient. I am using the airco much more for heating than cooling (i live higher north i guess). When the airco was installed it was put on the North side of the house so its always in the shade. So I was wandering if putting the airco in the sun would make a difference with heating the house.
Looking at your experiment, probably not. It might help a bit if the sun hits a larger area and the airco sucks in the air over that area (e.g. flat part of the roof).
I think you have it.
GFM
Did I miss something or was the return air 5 degrees cooler when the AC was shaded? Does that not translate to cooler air in the house?
It does not. Return temp is not a function efficiency. Temp split is the measurement of efficiency.
GFM
My condenser was directly exposed to the sun (Coleman brand). I ziptied some louver vent / return air grill in front of the fins which inhibits the air minimally but blocks the sun when oriented downwards. My temperature from supply vents at the second floor with air infinity booster fans dropped from minimum of 60 degrees to minimum 56-58 degrees. I think the sun exposure factor is minimal unless your fins/coils are exposed and get heated up by the sun.
There are far too many variables here to make any judgement. Condenser fans work on very small air pressures. Any blockage can be important.
Reduction in air temp could be due to an increase in head pressure from the louvre installation.
In any case, take the junk off the condenser and let it breathe.
GFM
try doing this experiment in Phoenix where the July temperature is around 115 deg daily - i have been keeping my a/c under a cantilever umbrella for several years (the umbrella is like 5 feet above the a/c unit so does not block the air flow) - without the umbrella you cannot even touch the housing on the a/c - with the umbrella you can - i think shading it in places like Phoenix absolutely help the unit (don't have numbers like you had)
I also have lived in desert areas (high desert in Ca). Nothing metal set in the sun could be touched.
However, temperature is not heat volume (BTU). The amount of heat is very low.
10# of sheet steel using a specific heat of .120 BTU per # raised from 100 to 180F equals 90 BTU. A 5 ton A/C is 60,000 BTU.
GFM
@@grayfurnaceman that's good info and thanks (the umbrella probably does nothing then other than make me feel better haha - i do keep it up high to not block the air venting out of the top of the unit) - i am not an a/c repairman (do have a background in electronics though) - it is pretty interesting (been watching numerous videos on how the techs measure various areas which catches my attention - still learning the terms) - one thing i also don't do is run my a/c that hard - only 80 degs during the day (79 at night) - i know a lot of folks run them at like 67 which i feel is too hard on the unit and shortens their life (i want the unit cycling on/off - not running constantly)
@@tonybaker8971 I have never understood the tendency to set the temp well below what you would want to have it in the winter.
And anything lower than 70F you run the risk of freezing the evap coil.
GFM
HELP ME Understand. Not much of an A/C guy, however, in the heat the supply inside was 59degrees and the return was 78degrees. But in the shade, the supply was 55 degrees and the return 74 degrees. That tells me the a/c in the house is colder in the shade and it will not take long to cool down, thus saving you money in electricity. Am I interpreting this correctly? Yes the Head pressure is the same, but if the air is colder then the A/C will not be on as long. Is this true?
The temp variations inside the structure are dependent the actual load. Not the performance of the air conditioner.
What we are testing here is the performance of the air conditioner. The performance of the air conditioner is exhibited by temp drop across the indoor coil. The return air temp has nothing to do with performance of the air conditioner.
GFM
Well this is good to know. We have two units at this 2016 house on the side that gets a lot of sun during the day. But the discharge air is actually not that hot at all (if that means anything).
I would like to have it to keep leaves and mowed grass from getting in but that would be a huge enclosure
Thanks for putting this video up, so now I know it's useless, hubby wont have to shade it no more
Afternoon heat is so hot
The amount of air being moved makes the sun's heat a negligible impact.
Agreed
GFM
I'm not an AC professional, but I don't understand how measuring the pressures are an effective way to quantify the actual benefit. Where the rubber meets the road would be to determine if there is an increase in cooling output and decreased up time. If the condenser is cooler, then I'd presume heat can be more readily expelled and the AC may not need to run as long. And if it is a package unit, the air flowing through the unit can be more effectively insulated from the exterior heat if it is shaded.
I am an A/C professional and how you determine if, it fact, you have reduced BTUs is by the head pressure of the unit. Higher BTUs that the unit must move, equals higher energy use.
GFM
@@grayfurnaceman still it's not measuring the output to the house.
@@truedox The reason I have not measured temperature drop across the indoor coil is there is no difference. I have tested and there is no change.
GFM
@@grayfurnaceman Yet you showed colder output and return with shading. Good luck to you anyway.
@@yournightmareracing1754 Variations in return temp are common throughout the day and during the on and off cycle. When the unit starts, return tends to be higher than at the end of the cycle. If there is no difference in temp drop, there is no difference performance.
GFM
the answer is dont add shade with the hopes of energy savings. but if a shaded area is available during installation go ahead and place condenser there to make a miniscule change that may become $50 savings over 20yrs. lol
I could not have said it better.
GFM
What about the amps
How about 100° days? Like 7 or 8 days in a row.
Im starting to grow Giant Sequoia so I can just shade the whole neighborhood
A Maple might be a better idea.
GFM
I guess as a hvac guy pressures are interesting but I mean just current draw is all I really care about
if there is a way to monitor the coil temperature, I guess the temperature of shaded and exposed coil are same.
There is no practical way to measure coil temp in the field. In fact, it is not necessary as the head pressure is a better measure of btu input.
GFM
I don’t know if it reduces usage I just know that the air in your house will be cooler
Why would you think that?
GFM
@@grayfurnacemanI believe heartcharm says that due to your readings of supply and return air. On your video it shows it being cooler when it is shaded. So wouldnt colder air going into your home reduce the A/C from being on the whole time thus saving you money?
@@JD-gm9op In a word, no.
The difference in return air temp is a difference in load, not performance of the outdoor unit. Load changes constantly, so return air temps change.
GFM
Shading appears not to be a big help and maybe a hindrance if it blocks the breeze.
What about the amp draw on the compressor but I thought that would be in the mix❤😢😮😅
Check the link at the end of the video.
GFM
@@grayfurnaceman 👍 thanks
shade the whole house, but make sure it blocks UV and IR rays lol :))
Yes but lets see in florida where we get 98 to 100 degrees. It may help
I just want to make a comment, it's not really a criticism but may appear so. But in all these tests you are running I think are starting out biased because your system is already operating at peak performance. The misting , the shading, these things to know if they work, need to be tested on AC units that are not already working at peak performance. I don't use any of them, but I know for an absolute fact I have seen on commercial units where maintenance people will literally run a hose of water on the unit to improve the performance on a really hot day. So I would have to assume that while it's not practical, clearly it provides a benefit in certain conditions. I would gather shading may potentially also provide some benefit. I really like your channel though. I have done a lot of proof of concepts in IT so I definitely understand testing equipment. You can't improve upon something unless it's operating under a certain threshold.
You are right. A properly operating air conditioner cannot be improved upon. If you were using an A/C from the 1970s, you may be able to improve its operation.
GFM
Thx. Misting and shading dont seem to help. You could move the entire condensing unit to Point Barrow. Long line length though. :)
Ya I mean direct sun I'm sure is not helpful but if it's worth the effort I don't know
Lol.. should do the measurement comparision from day time vs night time
The comparison would have little value as the temps and solar gain of the structure would not be the same.
GFM
I would think that shade and or water would only show a benefit with temps over 100 degrees, I have an older big widow unit that is shaded but when Texas summers get over 100 with low humidity it will almost quit cooling, I only have to spray it down once and not a lot to make it happy.
thanks for this good sir ...
Welcome
GFM
Too little time difference used
In AZ in my development Concrete walls are built FOOT around the Condensers leaving only a foot space. ( one side open). Keeps out the sun except on the top. This video puts that to rest.
not in the sun ....
"The complaint has been" does not look good from wife :)
Maybe you should listen to her.
GFM
I see a shadow
Nope
Dude, your answer is in the beginning, you had the head pressure at around 350PSI then when the sun was on it to was around 430PSI.... Your answer is the appropriate shading dose help.... Also you should also wait about 1/2 an hour to an hour...
Watch the video. The ambient changed between the earlier part of the day and the late afternoon.
GFM
@@grayfurnaceman that's what the shade is suppose to reduce..... Everyone knows if its a hot day you don't sit in the sun, you sit under the shade.... Same applys to your ac :)
1st.