Every year I install this sunsail to shade my ac unit.
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There's no radiator, it's a heat exchanger.
You have two sections in your heat exchanger. One part wants the cooling agent cold so it can effectively imterchange heat from your room into the cooling liquid. The other part wants the cooling agent hotter than the air outside so it can effectively dissipate the heat to the outside. To achieve that the liquid gets compressed. On the cold side it gets cooled with airflow.
I don't think sunlight will change anything significant in that mechanism.
I think it’ll have an effect. If you think of the cross section of the piping in the condenser (radiator in the outside unit shown in photo), you have heat trying to transfer from the fluid on the inside diameter, through the pipe wall, then to the air surrounding the outer diameter.
Heat has to flow from hot to cold, so ideally you have a gradient from hot to cold going from inside to outside.
But suppose the sun intensely heats that pipe wall and it ends up higher than either fluid on either side of it. Now you’ve got heat flowing from the wall to both inside and outside.
Not saying that ever happens, but every degree warmer that the pipe wall is, is a slow down in the heat transfer rate. Less of a gradient for the heat flow.
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Have you been able to quantify how much more efficient your unit is because of the shade?
wrote last edited by [email protected]I have an emporia energy meter. While I can't answer your question exactly, I have sprayed mine with a hose during the hottest part of the day and watched the power usage drop a decent amount. So I imagine as long as the shade wasn't too expensive it'll pay for itself.
Sprayed it down with the hose again. Pic added showing energy usage drop. Doesn't last long from water, but does show it not working as hard when cooler.
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For now.
The fun thing about HOA’s is that they can change and are absolutely dynamic. You never know when Karen’s crew is going to come into power.
Oh, they also changed the bylaws so that further changes to the bylaws require 75% approval from all homeowners in the neighborhood. Karen's crew is going to have to do a lot of work if they want to make any significant changes.
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I'm glad it's working out for you, but fuck if I'm about to pay some self appointment group to tell me what kind of fence or shed is unacceptable for me to own on my own property.
If I want to plop down a shopping container on my own front lawn, anyone who doesn't like it can kick rocks.
And that's why I'm glad there are properties without an HOA because I don't want to have to see the shit you put on your front lawn.
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I think it’ll have an effect. If you think of the cross section of the piping in the condenser (radiator in the outside unit shown in photo), you have heat trying to transfer from the fluid on the inside diameter, through the pipe wall, then to the air surrounding the outer diameter.
Heat has to flow from hot to cold, so ideally you have a gradient from hot to cold going from inside to outside.
But suppose the sun intensely heats that pipe wall and it ends up higher than either fluid on either side of it. Now you’ve got heat flowing from the wall to both inside and outside.
Not saying that ever happens, but every degree warmer that the pipe wall is, is a slow down in the heat transfer rate. Less of a gradient for the heat flow.
That makes sense. I was completely focused on only the device.
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While they both interchange heat, the principle of evaporators and radiators is different.
The condenser and the evaporator are both evaporators
Did you add that to prove yourself wrong?
probably just a brain fart - they've both heat exchangers.
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Shading the condenser unit keeps it cooler and increases it's efficiency and helps keeps my electricity costs down. The sail is high enough and mesh like so that it doesn't trap the hot air. In fact it creates a slight wind tunnel effect. The shade it provides lasts during the hottest part of the day and a tree helpfully blocks the sun for the remainder. The unit is never in full sun this way. Keeping the weeds and other debris away from the unit so that it gets good airflow and cleaning the condenser every year also help with the units efficiency.
You're blocking 300-500 W of solar radiation on a heat exchanger that runs 20-100% of the day. So yeah you're definitely going to get some improvements. Most notably it will run less often because it isn't dealing with the excess heat.
AC units SHOULD be designed for 100% duty cycle. But we all know that nothing is really capable of that - even industrial stuff. So if your shade reduces the duty cycle by a few percent, you might increase the longevity of the unit by an order of magnitude.
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probably just a brain fart - they've both heat exchangers.
wrote last edited by [email protected]Yes they have, but not every heat exchanger is a radiator.
I mean, youll get your point across and people will understand you, but coming all like "I hate to be that guy.." they should at least be correct.
Downvoting me and upvote the wrong information doesnt change reality. Lemmy is so much worse in that regard than reddit.
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I have an emporia energy meter. While I can't answer your question exactly, I have sprayed mine with a hose during the hottest part of the day and watched the power usage drop a decent amount. So I imagine as long as the shade wasn't too expensive it'll pay for itself.
Sprayed it down with the hose again. Pic added showing energy usage drop. Doesn't last long from water, but does show it not working as hard when cooler.
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Shading the condenser unit keeps it cooler and increases it's efficiency and helps keeps my electricity costs down. The sail is high enough and mesh like so that it doesn't trap the hot air. In fact it creates a slight wind tunnel effect. The shade it provides lasts during the hottest part of the day and a tree helpfully blocks the sun for the remainder. The unit is never in full sun this way. Keeping the weeds and other debris away from the unit so that it gets good airflow and cleaning the condenser every year also help with the units efficiency.
Interesting. I should see how much sun my units get.
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This is interesting. Gut says that it does increase efficiency. Thing I'm questioning is by how much?
Anybody got numbers or a good educated guesstimate?
https://www.aceee.org/files/proceedings/2002/data/papers/SS02_Panel1_Paper24.pdf
Shading the compressor can help but it can also hurt.
Those units can draw enormous amounts of air. Unless the shading covers a very wide area around the compressor, it's likely to mostly pull in air that wasn't shaded and is still at normal ambient temperature.
If the shading obstructs airflow, it can reduce the efficiency of the unit.
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https://www.aceee.org/files/proceedings/2002/data/papers/SS02_Panel1_Paper24.pdf
Shading the compressor can help but it can also hurt.
Those units can draw enormous amounts of air. Unless the shading covers a very wide area around the compressor, it's likely to mostly pull in air that wasn't shaded and is still at normal ambient temperature.
If the shading obstructs airflow, it can reduce the efficiency of the unit.
Nice source! Thank you kindly.
Planting trees and shrubs close by a condenser may actually reduce system
efficiency due to impedance of effective air movement. We conclude that any savings
produced by localized AC condenser shading are quite modest (<3%) and that the risk of
interrupting airflow to the condenser may outweigh shading considerations. The preferred
strategy may be a long-term one: locating AC condensers in an unobstructed location on the
shaded north side of buildings and depending on extensive site and neighborhood-level
landscaping to lower localized air temperatures.Tracks with the gut feeling. Shade will only marginally improve efficiency but constricting flow definitely hurts. Units are best installed on the North/Northeast sides of houses in the northern hemisphere.
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IIRC, my AC guy said the vertical throw of those units is far higher than that, I wonder if that translates into it sucking in more of it's own air (less efficient, higher cost)? Then again, UV seems to destroy everthing...
This is what I came up with. I'm not seeing any heating of the siding it's hard to tell on the sail as it's in direct sun. Also the unit is just under the corner of the sail so air can definitely get up and around. There's about F10* difference between the siding in direct sun and the condenser.
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Nice source! Thank you kindly.
Planting trees and shrubs close by a condenser may actually reduce system
efficiency due to impedance of effective air movement. We conclude that any savings
produced by localized AC condenser shading are quite modest (<3%) and that the risk of
interrupting airflow to the condenser may outweigh shading considerations. The preferred
strategy may be a long-term one: locating AC condensers in an unobstructed location on the
shaded north side of buildings and depending on extensive site and neighborhood-level
landscaping to lower localized air temperatures.Tracks with the gut feeling. Shade will only marginally improve efficiency but constricting flow definitely hurts. Units are best installed on the North/Northeast sides of houses in the northern hemisphere.
If your unit is a heat pump, are you then paying for that savings in the winter when it doesn't benefit from any solar warmth to help heat your house? If so, I wonder if it is a relatively balanced outcome or if one of the seasons has a bigger impact. I imagine it depends in part on which season is more extreme in your area.
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I have an emporia energy meter. While I can't answer your question exactly, I have sprayed mine with a hose during the hottest part of the day and watched the power usage drop a decent amount. So I imagine as long as the shade wasn't too expensive it'll pay for itself.
Sprayed it down with the hose again. Pic added showing energy usage drop. Doesn't last long from water, but does show it not working as hard when cooler.
Thank you for that visual! And for the new item to research for my home (the meter).
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I just want to say that I heart you. Like a lot.
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If your unit is a heat pump, are you then paying for that savings in the winter when it doesn't benefit from any solar warmth to help heat your house? If so, I wonder if it is a relatively balanced outcome or if one of the seasons has a bigger impact. I imagine it depends in part on which season is more extreme in your area.
I would think so. Another factor would be dropping leaves in the fall and winter so less shade, a good thing, in this case.
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"All this"
Its like 2 eye bolts, some rope, and a mesh sail lmao
If you spend all your time chasing pennies, the dollars are going to float on by. The deeper research says it's better to make sure the unit is clean and maintained than the silly sail.
