Airflow between keezer and cabinet...why?

[MonkeyWrench]

Is a fan needed?

Is a gap enough?

Is the gap even needed?

What's the purpose? Will the keezer sweat without it?

I've read through tons of builds, I probably just over looked the reasoning behind this.

Thanks all!

 

[DrDarwin]

It's all about heat management. If the hot side of the compressor coil system isn't on the back, it's embedded in the sides and front. In frost-free freezers there is also a heating cycle which melts the frost off of the internal chilling coils. In both cases, the system gets hot, and can be damaged without proper airflow.

If using the recommended gap (3" - 6" in most cases) for a particular freezer, the air has to be able to escape the side of the system. Hot air will collect if it doesn't have a path up the sides of the freezer and into whatever room it's in to dissipate. If I understand your second question, a gap between a wood shell and the side of a freezer is not enough alone, unless that gap goes from "floor to ceiling" if you will.

Oftentimes people building keezers will circumvent open sides by installing a fan or fans so that the hot air can be forced out of the system, and the freezer won't overheat.

 

[Mrott]

Based on my understanding of its purpose, a freezer works by taking the heat out of the inside, and moves it to the outside of the freezer. The heat is moved to the skin of the freezer as a disbursement method, then the natural air flow around the freezer helps to remove said heat to keep the skin at a cooler, consistent temperature. By not providing a gap and/or adequate airflow, the skin will retain its heat which will make the compressor work harder to keep the contents cold thereby overworking and shortening the lifespan of said compressor.

Now, on the flip side of that, there are people that have glued wood straight onto the outside of the chest freezer and reported no problems.

In my personal (non-professional) opinion, since the freezer is designed to keep the contents...well...frozen... and you're using this as a keezer so you're going to maintain an internal temperature of 38-42 ish the freezer will not be working as hard, or cycling as often to maintain a warmer temperature. In turn, it will naturally not be working as hard, so if you were to increase the load on the freezer (by not providing a space between the skin and shell) then it might be only increasing the load to what it would be doing to maintain a normal frozen temperature. So at that point it's just a matter of how much energy you want to be consumed.

Of course I have no hard evidence or statistics to back up my opinion, but it is what it is and I'll offer it free of charge with the waiver that if you follow it and it f*cks something up, don't blame me.

As for the fan, it just helps to circulate said air past the skin in the void between the skin and shell.

Hopefully this more or less answers your questions.

 

[DrDarwin]

Mrott's got it right with his non-professional opinion. It's a thermodynamics problem.

A freezer basically works by removing heat from the inside and putting it on the outside. It does this by compressing a fluid on the hot side, and allowing it to expand on the cold side. The hotter the hot side is, and the colder you want the cold side, the harder the compressor has to work (longer really). The damage that can be caused to the freezer is from overworking the compressor.

 

[MonkeyWrench]

I do understand refrigeration systems, guess I don't know exactly how chest freezers are built.

Basically, you would only NEED to have an air gap where the condeser coils are? Right?

So lets say the condeser coils are in the back or bottom, you really could just glue the wood directly to the skin of the freezer on the front and sides, no?

 

[DrDarwin]

I do understand refrigeration systems, guess I don't know exactly how chest freezers are built.

Basically, you would only NEED to have an air gap where the condeser coils are? Right?

So lets say the condeser coils are in the back or bottom, you really could just glue the wood directly to the skin of the freezer on the front and sides, no?

Chest freezers have many configurations, but yes, if the coils are on the back it would be fine if you glued wood directly to the sides of the freezer.

 

[JuanMoore]

I do understand refrigeration systems, guess I don't know exactly how chest freezers are built.

Basically, you would only NEED to have an air gap where the condeser coils are? Right?

So lets say the condeser coils are in the back or bottom, you really could just glue the wood directly to the skin of the freezer on the front and sides, no?

Correct, but the condenser coils in most chest freezers run just under the skin around all 4 sides of the freezer. This is why drilling through the sides or back is not advised. I covered the front and sides of my keezer using thin copper sheet with a mesquite frame. This way it looks like a piece of furniture, but can still shed heat effectively. If I were going to use all wood, I'd either use a very thin veneer or panelling, or create a gap and install fans to circulate the air.

 

[ellijo89]

yes that should be correct. Since if they are on the back or bottom then there shouldn't be any in the walls. As long as the coils have air circulating around them should be golden . On a side note screw thermodynamics lol

 

[MonkeyWrench]

Great, thanks for the input.

I'm going to inspect my freezer tonight and see what I can find. If the condenser is accessible (by removing back/bottom) I'd like to clean it for piece of mind anyways. I just picked up this 14cf freezer this weekend for $75.

 

[MonkeyWrench]

Guess I figured out why.

I plugged in my "new" freezer and using my Raytek checked temp all over the skin. There were areas that went from ambient of 64 to over 85 within 5 min. The entire skin seemed to raise a few degrees with certain areas being warmer than others, so looks like the condenser is spread out over the whole outer surface of this particular freezer, which is a 14cf Roper.

So yep, looks like an air gap is going to be needed, maybe a fan as well, wouldn't be a bad idea.

I was thinking these were more like a fridge, just with the condenser attached to the inside of a skin so the skin acted like a heat sink, I was partially right, I was just assuming that skin was the back or bottom, not the entire surface.