Copper coil pipe in chest freezer to heat exchange radiator

[SoakedUp]

How efficient in cooling do you think copper pipe coiled up in a 5cuft chest freezer fed to a 12v pump and heat exchange radiator with a 12v fan would be to keep a small solar room cool?

Would there be any problems with the pipes freezing inside the freezer or would the moving water prevent that from happening? I’m trying to keep a small solar room under 90 during hot 110 degree summers in the Southern California desert.

 

[DThames]

No room for a small AC unit?

 

[SoakedUp]

No room for a small AC unit?

It’s more the power usage required to run a AC and the hole required in a wall. It’s in a shipping container and I don’t want to cut a hole into the steel wall at this time. Trying to find an alternative way.

A chest freezer uses 100w plus small fan 50w and small pump 20w, I can stay under 180w.

An AC unit is going to be minimum 5-600watts.

I’m just not sure how much cooling I’ll get from the freezer.

 

[42OhmsPA]

Thinking out loud...
Won't the heat generated by the freezer compressor warm the space? Won't the freezer draw more power because of the increased cooling load from the coil? Won't you have condensation issues?
Consider a mini split?

 

[SoakedUp]

Thinking out loud...
Won't the heat generated by the freezer compressor warm the space?

Yes, slightly.

Won't the freezer draw more power because of the increased cooling load from the coil?

Max draw of the freezer is 100w. So it will continuously pull 100w instead of cycling on and off

Won't you have condensation issues?

Typical 5-15% humidity in the summer at my location. I’m not too worried about condensation but it’s always something to consider.

Consider a mini split?

I have. And still am. The main problem with a mini split is the power usage and the hole required in the container wall to feed the lineset out to the condenser unit which I’m trying to avoid.

 

[Sky-HHI]

You are just moving heat around, from the room, to the freezer, back into the room from the heat made by the freezer. You will only make the room hotter. you need to remove the heat to the outside , that is what an AC unit does. It transfers heat from inside the room to the outdoors.

 

[Darren67-72]

Your idea is a good thought. I agree, you will need a way to get the hot outside. Perhaps 2 small holes for the copper pipe to go outside and another heat exchanger. You are basically making your own mini split. ?

 

[fourtytwo]

I used something similar to cool a wine rack many years ago but I put the whole reservoir tank (of glycol mix of course) in the freezer so it had a lot more surface area. The wine rack was right next door heavily insulated with 2" polystyrene but still needed lots of copper pipe in its heat exchanger. Circulation was by grid washing machine waste pump. Efficiency!! whats that lols........

 

[Bluedog225]

I get not wanting a hole in the conex. But getting the compressor outside the conex will help efficiency. You could put underneath and have small copper pipe holes in floor.

No idea what kind of cooling you would get.

A much more off the shelf idea is a two hole portable air con. Not a single hose version. The conex floor is 1.25”. Holes are easy to patch well and permanently. Higher consumption but it will be on most during the heat of the day when sun is out.

And 6” holes for vents in conex are a good idea for small, constant airflow if the AC doesn’t work out.

Or a boxed in inverter window unit venting through floor. Though not ideal. Would need big hole.

 

[DThames]

Yes, slightly.

Max draw of the freezer is 100w. So it will continuously pull 100w instead of cycling on and off

Typical 5-15% humidity in the summer at my location. I’m not too worried about condensation but it’s always something to consider.

I have. And still am. The main problem with a mini split is the power usage and the hole required in the container wall to feed the lineset out to the condenser unit which I’m trying to avoid.

Without any math, most would know right away that any heat removed by a freezer would be added back by the freezer running if it is in the same space. Like Wile-coyote blowing on the sail with the fan.

 

[SoakedUp]

I actually

I get not wanting a hole in the conex. But getting the compressor outside the conex will help efficiency. You could put underneath and have small copper pipe holes in floor.

No idea what kind of cooling you would get.

A much more off the shelf idea is a two hole portable air con. Not a single hose version. The conex floor is 1.25”. Holes are easy to patch well and permanently. Higher consumption but it will be on most during the heat of the day when sun is out.

And 6” holes for vents in conex are a good idea for small, constant airflow if the AC doesn’t work out.

Or a boxed in inverter window unit venting through floor. Though not ideal. Would need big hole.

I actually already fed two 1” flexible conduit through the floor for the solar dc wire feed and then another for AC out. If I do an air conditioning unit like a mini split I was going to drill a 3” hole in the floor to feed the line set out. Still not ideal but easier to patch than the Corten steel wall if I want to move stuff or change my plans.

I’m still not sure about power usage of a AC unit. I’d need a bigger inverter and more batteries. I only have 1 SOK 206ah and a Victron 12/1200. While it does power my cabins MR. Cool 12k btu mini split I installed, it’s pushing the limits of the current equipment. Pulls about 1200watts on start up and then drops to about 5-600watt. I’m assuming it would stay closer to 1000watts during the higher summer temps.

 

[Checkthisout]

Are you trying to keep equipment cool?

Without insulating that thing, you need an exhaust fan. A puny little freezer isn't going to do anything.

A 15k BTU a/c unit would be useless as well if that thing is in the direct sun.

 

[Deltasierra]

To be efficient you have got to use the cooler night air to make a storage cooler, the opposite of a storage heater. Circulate Cool air through an insulated stack of concrete blocks at night, in the day circulate that through the inverter space