Override windows air conditioner not working

[dendron8]

Ok so ive read a few posts on this and I thought i understood how top do this.. i have a frigidare 5000btu unit listed here:

https://www.amazon.com/dp/B00W2KG92Y/ref=cm_sw_r_cp_awdb_t1_O80lDbFBZKGTS

I took off the cover and moved the copper temperature sensor out. I bought a night light (replaced the tiny bulb with a larger one that was hot the minute i plugged it in) put an incandescent bulb in, created a "hot box" for the sensor And the light, and cranked it up. I can't seem to get the temp below 62/63. What am i doing wrong?

 

[Bobby_M]

What is the ambient temp in the space you are trying to cool? The air coming out of the AC will only be about 20 degrees colder than the air coming in. The probe override trick just keeps the AC from shutting down the compressor when it's built in thermostat gets satisfied. Most AC thermostats can only be lowered to about 62F so if you want it to cool down to 40, you have to keep the probe above 62F.

Back to the ambient temps... If the room is 83F, measuring 63 coming out of the AC vent means its working. As the room gets colder and colder, you'll see the output temp drop as well.

 

[dendron8]

Interesting. So the return air (the big slotted area just below where the cold air comes out? ) needs to be at 55 if i want the unit to blow 35 air?

 

[applescrap]

Interesting. So the return air (the big slotted area just below where the cold air comes out? ) needs to be at 55 if i want the unit to blow 35 air?

I use window ac too, and love them. They really only spot cool one room. I try to cool more with fans, but each room needs one. I basically have one in each room. I dont know how much you are trying to cool, but 5000 btu, wont do to much. I have two window units in my house and they really only do the room they are in.

You can run them hard and as Bobby said correctly, you are forcing the compressor to stay on, which in theory is also hard on it. I have had mine for years. Every few years I crack them open and clean them with water. The bottom line is I wouldn't expect 5k btu to cool anything smaller than a very small kids room. My son's bedroom is 8k btu and ours is 10k btu. I looked that up and as I suspected they run about 150 dollars new. If it cools a small room with the door shut, which I suspect it does well, you are getting your money worth. No need for that trick I also suspect. Setting it as low as it will go, a temp it will never reach, does the same thing essentially. If you run them when it's too cold they freeze. Or at least I have frozen mine. They are so durable. I got the portable types on groupon for my daughters room and downstairs. They work nice too.

 

[dendron8]

I am trying to cool an insulated box that is 4' x 1' x 2'. When i ran the test, i did not have the box hooked up to the unit.. i guess that's what i need to do.

 

[Bobby_M]

Interesting. So the return air (the big slotted area just below where the cold air comes out? ) needs to be at 55 if i want the unit to blow 35 air?

Correct. It would be a miracle to expect air to drop 50F in a single pass through a 2" wide coil. However, it's a direct feedback loop. In a confined space, that 20F differential starts to make headway. Soon that 63F output air drops the ambient temp to 70F and that going in comes out at 50F. Then the room is cooling to 60F and the air is coming out at 40F and on and on until either your external thermostat is satisfied or the room takes on more external heat than the AC can handle.

The heated override of the built in thermostat is ONLY making sure that the AC's built in thermostat doesn't do anything at all. In this case, you will plug the AC's power cord into an external thermostat/controller such as the Inkbird 308 or the like. That's now the only thing that will cause the AC to turn on and off. Depending on how cold you want that room/space/box to get, you may be better off hardwiring your controller into the compressor wiring so that you can leave the fan running to avoid icing on the coil.

 

[Bobby_M]

I am trying to cool an insulated box that is 4' x 1' x 2'. When i ran the test, i did not have the box hooked up to the unit.. i guess that's what i need to do.

Correct, an AC of that size can only cool a small confined space down to that cold of a temp and it will get there pretty fast once that box is built. You will need an external thermostat to make it stop at 35 or you'll just freeze the coil and it will start warming back up fast.

 

[Bobby_M]

Here's what you actually need to do. Leave the AC's setting to maximum cool on the thermostat and set it to Hi Cool.

Get yourself an Inkbird 308 Wifi (I sell them). Take your lightbulb power source and plug it into the Inkbird's COOLING outlet.

The reason for this solution (which is the only one that will work) is that the AC's fan will run continuously to keep coil freezing to a minimum. When the inkbird is calling for cooling of the box, it will turn your lightbulb on and fool the AC into thinking it just got really hot in the room and will engage the compressor. You may still have icing problems over time so you'll have to do a defrost occasionally.

 

[mongoose33]

Last year I bought a window air conditioner (5000btu) to use to try to cool a ferm closet. I was able to get it down to about 50 degrees. This, however, was while it was in the window, so it was dumping waste heat outside. If the air conditioner is inside and that waste heat is partially being drawn back into the air conditioner, it's going to have a harder time.

 

[Bobby_M]

Last year I bought a window air conditioner (5000btu) to use to try to cool a ferm closet. I was able to get it down to about 50 degrees. This, however, was while it was in the window, so it was dumping waste heat outside. If the air conditioner is inside and that waste heat is partially being drawn back into the air conditioner, it's going to have a harder time.

It would mostly be based on how well insulated and sealed the chamber is.

 

[dendron8]

Thanks bobby, i do already have an inkbird wifi (Amazon for $35!). I have three other inkbirds that control my kegerator, my keg ager (freezer) And my ferm chamber (fridge).

I already have the box built (styrofoam and tuct tape) and I'll let you know how it goes. Thanks for the help so far!

Here's what you actually need to do. Leave the AC's setting to maximum cool on the thermostat and set it to Hi Cool.

Get yourself an Inkbird 308 Wifi (I sell them). Take your lightbulb power source and plug it into the Inkbird's COOLING outlet.

The reason for this solution (which is the only one that will work) is that the AC's fan will run continuously to keep coil freezing to a minimum. When the inkbird is calling for cooling of the box, it will turn your lightbulb on and fool the AC into thinking it just got really hot in the room and will engage the compressor. You may still have icing problems over time so you'll have to do a defrost occasionally.

 

[mongoose33]

It would mostly be based on how well insulated and sealed the chamber is.

Well, not in this case. I built a little "closet" to enclose my Spike fermenter, hoping to reduce ambient around the fermenter so it could crash to lower temps. Put the air conditioner in the window, had the fermenter and "closet" right next to it to get the air blowing into the closet.

Measured at 50 degrees using a Thermopen MkIV.

It would vary during the day depending on outside temps, but only getting 62 degrees strikes me as pretty weak unless it's drawing very warm air back into the input vent.

Here's the "closet." It was made of 2'x4' 1/4" pegboard, so the air going in would have a place to exit.

BTW, that experiment ended when I wasn't able to drop the temp very much more than I had been. Guess what? When you're blowing 50-degree air into the "closet" it's simply warming things up that are lower than 50 degrees.

My last hope for this is to make a "closet" out of 2" foamboard. No air conditioner, just something that hopefully would isolate the fermenter from ambient. The only thing holding me up from doing that is finding a way to cut the sections perfectly square. Yeah, there are hot wire methods and such, but I want something where I don't have to build something just to get the pieces to build something.

 

[dendron8]

That did it! (And yes this is $10 worth of styrofoam taped with a $13 roll of tuct tape)

Ive got some air cracks to fill but the thing cooled down from > 90F to 50F in about two minutes. Yippee!

 

[applescrap]

Well there you go. Coils probably wont even freeze if it's that efficient. Idk. Super clever solution.

 

[Bobby_M]

Well, not in this case. I built a little "closet" to enclose my Spike fermenter, hoping to reduce ambient around the fermenter so it could crash to lower temps. Put the air conditioner in the window, had the fermenter and "closet" right next to it to get the air blowing into the closet.

Measured at 50 degrees using a Thermopen MkIV.

It would vary during the day depending on outside temps, but only getting 62 degrees strikes me as pretty weak unless it's drawing very warm air back into the input vent.

Here's the "closet." It was made of 2'x4' 1/4" pegboard, so the air going in would have a place to exit.

BTW, that experiment ended when I wasn't able to drop the temp very much more than I had been. Guess what? When you're blowing 50-degree air into the "closet" it's simply warming things up that are lower than 50 degrees.

My last hope for this is to make a "closet" out of 2" foamboard. No air conditioner, just something that hopefully would isolate the fermenter from ambient. The only thing holding me up from doing that is finding a way to cut the sections perfectly square. Yeah, there are hot wire methods and such, but I want something where I don't have to build something just to get the pieces to build something.

View attachment 636158

The failure here is directly related to the pegboard. You don't need to vent this enclosure because the air conditioner works on a mostly closed system. Air is sucked in on the lower portion, blown over a cold coil and returned out at the top. If your closet was fully sealed except for the spot where the AC face penetrates into it, you could get that closet easily into the 30's to the point where you wouldn't need any interior cooling. Again, the AC is only capable of dropping the air temp by 20F. In a small closed system, the input air will continue to fall until the whole system freezes solid or a thermostat stops it.

 

[mongoose33]

The failure here is directly related to the pegboard. You don't need to vent this enclosure because the air conditioner works on a mostly closed system. Air is sucked in on the lower portion, blown over a cold coil and returned out at the top. If your closet was fully sealed except for the spot where the AC face penetrates into it, you could get that closet easily into the 30's to the point where you wouldn't need any interior cooling. Again, the AC is only capable of dropping the air temp by 20F. In a small closed system, the input air will continue to fall until the whole system freezes solid or a thermostat stops it.

I'm going to have to respectfully disagree. Unless you have a way for the air to move through, you're not going to be able to blow much in. The pegboard holes also allowed for the air to flow out from all around and not just create a feedback loop or a channel through which the air flowed and didn't affect the rest.

In other words, it would be like trying to blow up a balloon where there was no place for the air to go.

 

[Bobby_M]

I'm going to have to respectfully disagree. Unless you have a way for the air to move through, you're not going to be able to blow much in. The pegboard holes also allowed for the air to flow out from all around and not just create a feedback loop or a channel through which the air flowed and didn't affect the rest.

In other words, it would be like trying to blow up a balloon where there was no place for the air to go.

Emphatic no. The AC is meant to run a closed loop in the environment in which it is deployed. You're not blowing air IN. You're sucking air out, cooling and then returning it. If you run an AC in a very small bedroom, do you think that you need to leave the door open? The air is coming from inside the room.

If you still think I'm crazy, don't take my word for it. Take a window AC apart and discover how it works. Too much work? Take the front cover off and turn it on. Put a piece of cardboard or paper against the evaporator coil and watch it get sucked right to it. That's because the fan is pulling room air through the evaporator coil to cool it off before blowing it out at the top back into the room.

 

[day_trippr]

I might be missing something here but if the evaporator side and the condenser side of an AC unit were moving the same air in a closed space why would it ever cool?
Clearly convention says the condenser side is external to the space being cooled by the evaporator side.

Or is this a question of how the evaporator side air flow is managed?

Cheers!

 

[Bobby_M]

Right. To further explain; A window AC is a box with two isolated sides. The side facing outside has the compressor and condensor coil. The side facing inside the room has the evaporator coil that gets cold. There is a single fan motor in the middle with fan blades on both sides of the split system.

 

[mongoose33]

Emphatic no. The AC is meant to run a closed loop in the environment in which it is deployed. You're not blowing air IN. You're sucking air out, cooling and then returning it. If you run an AC in a very small bedroom, do you think that you need to leave the door open? The air is coming from inside the room.

If you still think I'm crazy, don't take my word for it. Take a window AC apart and discover how it works. Too much work? Take the front cover off and turn it on. Put a piece of cardboard or paper against the evaporator coil and watch it get sucked right to it. That's because the fan is pulling room air through the evaporator coil to cool it off before blowing it out at the top back into the room.

You're not crazy, but the air conditioner wasn't inside the closet. It was in the window, blowing cold air into a small opening a the top of that closet. It wasn't drawing air back in from the closet, but from ambient. There had to be a way for that air to also leave the enclosure.

I got the environment inside that closet down to 50 degrees, which is about what was coming out of the air conditioner. It wasn't enough to allow me to get the fermenter down to 32.

 

[Bobby_M]

You're not crazy, but the air conditioner wasn't inside the closet. It was in the window, blowing cold air into a small opening a the top of that closet. It wasn't drawing air back in from the closet, but from ambient. There had to be a way for that air to also leave the enclosure.

I got the environment inside that closet down to 50 degrees, which is about what was coming out of the air conditioner. It wasn't enough to allow me to get the fermenter down to 32.

OK, but why didn't you allow the air to be drawn back in to the AC from the closet? I was saying that's how you COULD get it to work the way you wanted. It sounds like the part I'm missing may be that the window AC wasn't just being used for this project but was actually there to cool the room and you were hoping to piggy back this usage off it.

 

[Stand]

I am confused about this. You could definitely get it down to 32 if you didn't have the holes venting.

Is the AC unit for the room as @Bobby_M suspects?

 

[Bubman]

It sounds like the part I'm missing may be that the window AC wasn't just being used for this project but was actually there to cool the room and you were hoping to piggy back this usage off it.

Exactly!!!

Like trying to cool you kitchen by leaving the refrigerator door open

 

[mongoose33]

OK, but why didn't you allow the air to be drawn back in to the AC from the closet? I was saying that's how you COULD get it to work the way you wanted. It sounds like the part I'm missing may be that the window AC wasn't just being used for this project but was actually there to cool the room and you were hoping to piggy back this usage off it.

The arrangement of the foundation meant I couldn't get the enclosure close enough to do that, not without building some chutes or something to channel the airflow.

I actually bought the air conditioner from WalMart specifically to do this. When it didn't suffice, I returned it. Satisfaction guaranteed. I wasn't satisfied.

I thought about keeping the air conditioner to cool the garage generally, but decided against it.

 

[Bobby_M]

The arrangement of the foundation meant I couldn't get the enclosure close enough to do that, not without building some chutes or something to channel the airflow.

I actually bought the air conditioner from WalMart specifically to do this. When it didn't suffice, I returned it. Satisfaction guaranteed. I wasn't satisfied.

I thought about keeping the air conditioner to cool the garage generally, but decided against it.

Oh well. It would have worked with a sealed foam box, tightly abutted to the entire front of the AC. Literally, exactly like you were hoping. You were so close.

 

[Stand]

It's too bad really because this is a pretty neat idea. If I had a window in my garage I'd probably give it a try. Having the ability to control the size of the chamber as well as keep the heat outside of the garage/house is just slick.

 

[Dland]

I thought most AC units will not cool that low, hence the somewhat pricey Coolbot solution, for using AC to cool a cold chamber.

I'm working on a AC based glycol chiller right now. (just need to get a properly sized cooler at this point). Anyway, I bypassed and removed the all the control electronics, so it is on full blast any time it is plugged in. Intend to use a 308 inkbird to switch it on & off when cooling is needed.

 

[Bobby_M]

I thought most AC units will not cool that low, hence the somewhat pricey Coolbot solution, for using AC to cool a cold chamber.

I'm working on a AC based glycol chiller right now. (just need to get a properly sized cooler at this point). Anyway, I bypassed and removed the all the control electronics, so it is on full blast any time it is plugged in. Intend to use a 308 inkbird to switch it on & off when cooling is needed.

the very first post in the thread shows the poor man's coolbot solution. Actuating the compressor by turning on a heat source coupled to the AC's thermostat probe. I also gutted my AC glycol unit but a little cartridge heater or lightbulb taped to the probe would have done it too. The one thing the coolbot does do well is sense ice on the evap coil which I believe restricts the unit from coming on again until the ice melts.

 

[Dland]

I also gutted my AC glycol unit but a little cartridge heater or lightbulb taped to the probe would have done it too.

The unit I used was remote control only, w no remote, I did screw around with bypassing the temp board, but soon realized getting rid of all but the 120V circuit was simplest option. Why rely on all that micro circuitry when it does not even need to be in the loop?

Edit: If the AC unit is to be run by another controller like an inkbird 308, all one needs hooked up is compressor, fan and capacitor.

 

[augiedoggy]

I'll share what I know... an ac unit lowers the temp in one pass up to 20 degrees ... It does not work any harder or less to make the air colder in one pass like the common misconception. it just keeps recycling the same air over and over taking it down 10-20 degrees per pass theoretically. Many fridges and cooler setups work the same way.
How cold you can get a chamber with one after tricking the units temp probe and causing it to cycle on and off longer more often for a longer amount of time until the desired temp is reached like a coolbot does. This all depends on the amount of insulation the chamber has. if the chamber is too big or the insulation value too low the smaller ac unit cant overcome these losses quick enough and will not be able to do the job without icing up while trying.

I have 2 walk in coolers one is 9.5ft by 8ft and the other is 8x9 roughly but they are only 70 inches high. I use a 24,500btu ac unit to cool one chamber down to 36 degrees and a 11,500btu unit for the smaller one also at 36 degrees they do this well because the insulation is 5" thick and the coolbot is setup to monitor evap unit temps and cycle/ shut off the unit to prevent it from icing up.
this feature is what makes the coolbot work so well. You can totally accomplish this with two temp controllers working in tandom... one monitoring the ac units evap coil and the other monitoring the chamber temp.

The downside it the part of the ac unit that sticks out the window normally is the part that draws ambient air in the sides and uses it to cool the condensor and pushes this warmed air out the back.. it causes my basement to get rather warm in the summer months were my cooler reside.
you also want at least 2 ft of space all around the sides and back of the ac unit to prevent it from sucking the warm air back into the sides and lowering the efficiency of the unit.

The same principal goes for a gycol chiller... They normally pull air into the unit at the condensor though then across the compressor instead of through the sides and push out through the condensor like a window ac unit (The exception to this rule are penquin chillers which are made from repurposed window ac units) BTW a huge penquin chiller was just released for brewing that is made from a repurposed commercial ice machine.

EDIT I posted this before reading the whole thread and see now that Bobby covered most of it.

 

[augiedoggy]

The unit I used was remote control only, w no remote, I did screw around with bypassing the temp board, but soon realized getting rid of all but the 120V circuit was simplest option. Why rely on all that micro circuitry when it does not even need to be in the loop?

Edit: If the AC unit is to be run by another controller like an inkbird 308, all one needs hooked up is compressor, fan and capacitor.

it will ice up with just one controller unless your using a huge ac unit to cool a tiny chamber... you need a second controller to control the heater that the ac units temp probe sees to prevent icing up. a coolbot is essentually that, two controllers.. one controlling a heater using evap coil temps as reference and the other monitoring chamber temp controlling normal on off control.

 

[augiedoggy]

the output of a cars ac unit is totally different since it uses flaps and fan motor speeds to control either flow or the amount of warm ambient air introduced into the air coming from the vents to make the air blow colder or warmer.

 

[Scrumpy!]

Good discussion that is perfect timing for me. I really appreciate Bobby's explanation of the closed air cycle on the evaporator side of the AC. Augiedoggy clarified the 20 deg drop in increments to round it out.

I have just built a 20 cu ft box under my work table. I have a GE 5K BTU AC ported into one end. I moved the AC's sensor from the evaporator fins to the outside of the box and wired up a cheap enclosure heater to keep it warm. I put a small ceramic heater in the box for fermenting at a controlled temp during winter months when my work-space gets cold. I have an average R of around 15 if I can believe the specs written on the styrofoam and foil insulation I used. I would have liked to get to R 25 as advised by CoolBot but did not have room. My lowest target temp is 35 deg so I can cold crash kegs or carboys. I hoped to control it all with a single ITC-1000.

On my first test run, I found that my AC was cycling every 3 min so I set the compressor delay for 5 min to allow the pressure to equalize before starting a new cycle. This configuration is not working well so far. I am icing when trying to get to temperatures below 50 deg so I will add a second ITC 1000 to plug into the evaporator fins to turn the unit off if it starts to ice. I see that some systems just shut the compressor down and let the fan melt the ice. That system would also have to have compressor delay built in.

The bigger issue is the short cycle time. I can't find any information on where to put the primary temp sensor. I mounted it about 4 ft away from the AC. The AC temporarily cools the air to any target temp in about 70 seconds before it can have much effect on the liquid filled carboys and kegs. The current configuration will take a long time to chill 25 gallons of liquid and take a toll on the AC.

I want to damp that sensor's response so the AC runs longer. Should I shield it with a short length of open ended PVC pipe? Should I move it to be directly below the AC? Should I put it in a small water bath so it responds more like my carboys? Any other ideas would be appreciated.

 

[Dland]

Your idea of a water(or antifreeze) bath for probe might work. My unit is a glycol chiller, not air box, so obviously different story, but the temp probe in glycol does not short cycle.

If you set the controller with a lower target temp with a higher trigger temp differential, you will also get longer runs. The liquid in carboys won't swing that fast, even if air temp has variation of 6-8 degrees.

 

[bracconiere]

i'll admit i just read the first post. but i don't get the lamp on the temp probe. i modded my oven a while back with a 200ohm resistor in series on the temp probe to get it to go lower...

i'd imagine for a A/C you could do something similar, and use the actual temp setting accordingly....

 

[augiedoggy]

i'll admit i just read the first post. but i don't get the lamp on the temp probe. i modded my oven a while back with a 200ohm resistor in series on the temp probe to get it to go lower...

i'd imagine for a A/C you could do something similar, and use the actual temp setting accordingly....

you need to have a heat source you can turn on and off to override the ac units built in control. and you need a secondary temp control to prevent the icing up of the unit. this is exactly how a coolbot works with a little heater instead of a bulb though.

 

[bracconiere]

you need to have a heat source you can turn on and off to override the ac units built in control

but temp probes just work on a set resistance... if you increase resistance, then it will go lower? that's what i did with my oven, stock it only goes down to 170-200f, now with the 200ohm resistor i can get it down to 90f....just using the stock temp knob....

 

[Scrumpy!]

Thanks for the suggestion. I'll try glycol. No bugs should grow in it and it will not evaporate as fast as water or alcohol.

Your idea of a water(or antifreeze) bath for probe might work. My unit is a glycol chiller, not air box, so obviously different story, but the temp probe in glycol does not short cycle.

If you set the controller with a lower target temp with a higher trigger temp differential, you will also get longer runs. The liquid in carboys won't swing that fast, even if air temp has variation of 6-8 degrees.

 

[Bobby_M]

Good discussion that is perfect timing for me. I really appreciate Bobby's explanation of the closed air cycle on the evaporator side of the AC. Augiedoggy clarified the 20 deg drop in increments to round it out.

I have just built a 20 cu ft box under my work table. I have a GE 5K BTU AC ported into one end. I moved the AC's sensor from the evaporator fins to the outside of the box and wired up a cheap enclosure heater to keep it warm. I put a small ceramic heater in the box for fermenting at a controlled temp during winter months when my work-space gets cold. I have an average R of around 15 if I can believe the specs written on the styrofoam and foil insulation I used. I would have liked to get to R 25 as advised by CoolBot but did not have room. My lowest target temp is 35 deg so I can cold crash kegs or carboys. I hoped to control it all with a single ITC-1000.

On my first test run, I found that my AC was cycling every 3 min so I set the compressor delay for 5 min to allow the pressure to equalize before starting a new cycle. This configuration is not working well so far. I am icing when trying to get to temperatures below 50 deg so I will add a second ITC 1000 to plug into the evaporator fins to turn the unit off if it starts to ice. I see that some systems just shut the compressor down and let the fan melt the ice. That system would also have to have compressor delay built in.

The bigger issue is the short cycle time. I can't find any information on where to put the primary temp sensor. I mounted it about 4 ft away from the AC. The AC temporarily cools the air to any target temp in about 70 seconds before it can have much effect on the liquid filled carboys and kegs. The current configuration will take a long time to chill 25 gallons of liquid and take a toll on the AC.

I want to damp that sensor's response so the AC runs longer. Should I shield it with a short length of open ended PVC pipe? Should I move it to be directly below the AC? Should I put it in a small water bath so it responds more like my carboys? Any other ideas would be appreciated.

You are getting short cycling because the space is so small and the cooling system is oversized. You can mitigate freezing by forcing the fan to run constantly. The best way would be to find the compressor activation wire and running that off the external controller. Where do you have the probe now? Attach it to your fermenter on the side oppposite the AC and put some insulation over it, like a 4"square.

 

[Scrumpy!]

Thanks Bobby,

I moved the sensor so it does not lie in the direct path of the air blast. I also put it in a one pint milk bottle full of water which reduced the fluctuation over each cycle to less than half a degree. I also added another inkbird in series to monitor the evaporator fins, set it at 33 with a 1 degree offset and put in a 7 min compressor delay.

These changes have extended the cycle to 11 min with the AC running for just over two minutes each cycle. The evaporator fins briefly get down to 31.5 deg after the AC shuts down at 33 deg. This has prevented icing so far. With the target temp set to 35 deg, I am down to 41.5 deg with two full corny kegs inside. The external temp is 68 deg.

I wondered if the AC was too big but 5 K BTU is about as small as I could find. If it is not reaching my target overnight I thought I would leave the fan on high but move the dial from high cooling to the midpoint between that and low cooling to see what happens. Will that reduce the load on the compressor and will it compensate for my over capacity?