Keezer lid/collar build - insulation

[Kerednai]

I would love a second opinion on how I plan to insulate the lid I just created for my Keezer. After a lot of back and forth & help on this forum I decided to create a new lid for my keezer to gain a small amount of extra head space and also have the option of putting my co2 tank outside the keezer. I was restricted by height as I wanted the keezer to be about the same height as another counter in my bar. Anyway I've posted picture of the new lid that was made from 1/4" birch plywood for the top and 2x4 red oak for the collar. We re-used the OEM seal from the original lid. As you can see from the pictures the lid is actually attached to a 3/4" counter which is oversized to allow me to re-use in the future with other freezers & is a more practical counter size for my bar.

What I am planning to do is:
- Use silicon sealant on the inside where the wood joins are.
- Use 2 R-5 foam boards back to back on the top of the lid to be 2" deep and be the equivalent of R-10. Attach to lid and each other with Adhesive.
- Use 1 R-5 foam board on the collar (side). That will end up coming about 1/4" into the freezer area but I don't think that will be an issue.
- Seal the foam joints. Still trying to decide how I want to do this. Maybe a foam compatible caulk or tape to look as neat as possible.

 

[day_trippr]

I used foil faced polyisocyanurate foam board for my custom keezer lid build as well, though just a single 1" thickness for R-6.0 all around. All the edges were covered with sticky foil tape and once all the pieces were dry fitted together as shown here I taped the gaps as well (don't have a picture of that).

That has proven to be adequate as the temperature plot attests - the compressor runs at around a 25% duty cycle, and that's with four small 12VDC fans running 24/7 inside.

fwiw, you can see my extensive custom-lidded keezer build here: https://www.homebrewtalk.com/threads/my-k3-14-8cf-keezer-build.689790/
This is the finished interior with all the plumbing and wiring and lighting...

Cheers!

 

[Deadalus]

There are probably estimates of R-value for both 2x4's and the plywood. Perhaps even for the wood species used but at least for wood thickness. The 2x4 is 6x thicker than the plywood if the plywood 1/4" is not nominal. Maybe 8x if the red oak 2x4 is actual.

 

[day_trippr]

Frankly I wouldn't be too concerned with insulating the lid in general as I suspect there isn't much "cold" lost via the lid as long as it's tight. I've built three keezers over 16 years or so, the first two using Craig's List chest freezers, and the first two just had a simple batt of fiberglass insulation loosely tossed in before the lid liner was fastened down. The current one did have a foamed-in-place lid (which is why I had to make my own) but even that was just a inch or so of blown foam. I suspect the manufacturers do this because it doesn't hurt the performance much and it is cheaper...

Cheers!

 

[Kerednai]

Thank for all the information day_trippr, extremely useful. Its hard to tell from the pictures, but did you put the foil side of the insulation on the inside of the freezer or on the outside against the wood? I believe theoretically its supposed to go on the outside, but I'm not even sure if it would make much difference in this application. I think it would provide a nicer looking face inside the freezer though.

 

[day_trippr]

The Johns Manville foam board I used had foil cladding on both sides, one side reflective silver, the other side white. In this application it doesn't seem likely to make any difference but I put the reflective side "out". I used it specifically for its low moisture absorption as well as its R-value.

Cheers!

 

[Kerednai]

The Johns Manville foam board I used had foil cladding on both sides, one side reflective silver, the other side white. In this application it doesn't seem likely to make any difference but I put the reflective side "out". I used it specifically for its low moisture absorption as well as its R-value.

Cheers!

OK that sounds ideal. Thank you.

 

[Indian_villager]

I would love a second opinion on how I plan to insulate the lid I just created for my Keezer. After a lot of back and forth & help on this forum I decided to create a new lid for my keezer to gain a small amount of extra head space and also have the option of putting my co2 tank outside the keezer. I was restricted by height as I wanted the keezer to be about the same height as another counter in my bar. Anyway I've posted picture of the new lid that was made from 1/4" birch plywood for the top and 2x4 red oak for the collar. We re-used the OEM seal from the original lid. As you can see from the pictures the lid is actually attached to a 3/4" counter which is oversized to allow me to re-use in the future with other freezers & is a more practical counter size for my bar.

What I am planning to do is:
- Use silicon sealant on the inside where the wood joins are.
- Use 2 R-5 foam boards back to back on the top of the lid to be 2" deep and be the equivalent of R-10. Attach to lid and each other with Adhesive.
- Use 1 R-5 foam board on the collar (side). That will end up coming about 1/4" into the freezer area but I don't think that will be an issue.
- Seal the foam joints. Still trying to decide how I want to do this. Maybe a foam compatible caulk or tape to look as neat as possible.

Also seal all your wood joints with HVAC tape.