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Could you pipe in cold air from outside, so you don't have to use the compressor on your cooler. When it is below freezing outside, you could use this vent on your dairy and produce cooler. And it may even help reduce energy costs on your freezers.
You would have an outside thermostat, that would open and close a door on the vent going outside. So when it is warm, your cooler works just like normal. But you would not need to compressor when the door is open.
would that work?
This has many names depending upon where you come from and what part of the HVACR industry you are in.
"Free cooling"
"Economiser" (not to be confused with screw compressors)
Yes it would work. But remember two vents in and out.
Would only work on a freezer ambient is below freezer temp.
absolutely that would work and has been done before, I've seen a chiller room built beside a freezer which has a tstat starting a fan which blows through a vinyl sock (similar to a wind sock at the airports), when the chiller is down to temp the fan stops and the sock drops and shuts off the vent. I admit this is not the most economical way of running a chiller as the freezer takes the load but it is a quick solution. using ambient air is a good idea for the chiller even if it is below freezing as the air off a bottle cooler evap is normally below 0 anyway to acheive bottle temp of 1 or 2 degrees.:cool:
As Mad said, its well known in AHU and do save a lot of energy when cooling needed in cold ambient.
In dairy product cold storage it will be different, first you need to install air filters, you cant just suck outside air. it have to be clean.
second thing is the amount of air, it have to be equal to the fans capacity.
Third thing is the insulation, you need to open part of the wall to let the air in and another place to let the air out. Fans should be sucking air out of the cold storage.
Last thing is the operation in summer when these openings should be hermetically closed, you don't want to loose in the summer all your energy savings from the winter.
Good idea, not cheap but wort a try.
Calculate how many days per year you can use free cooling, cost of the system and how many KWH you will save.
Bowman316 I have seen it work in a hvac system. I have also seen a cool room cooling system that Paul J describes.It did not work. The room is 30 by 60 feet built in a corner of the cold storage building. The room has 2 motor driven louvers 4 by 4 feet that can be open or closed.The room had two major problems 1 impossible to control the temperature. 2 the amount of warm damp air put a very large load on the evaporater closest to the room. We changed plans and went with a evaporater installed in the room and blocked the louvers.WE now have no temperature control problems. C.D.
316 on rereading your post I realized that for using outside air for cooling you will need a fan or fans to circulate the air for even cooling. C.D.