Insulation in Cabinets?

[reubenray]

I have read before where hard foam insulation was put into the ceiling and the outside wall of the cabinets to fight the heat some. How was y'all securing it? I am looking at this product Shop Pactiv R4 Unfaced Polystyrene Foam Board Insulation (Common: 0.75-in x 4-ft x 8-ft; Actual: 0.75-in x 4-ft x 8-ft) at Lowes.com.

[MSHappyCampers]

Don't think I've heard of anyone using anything that thick. It would take up a lot of space in the cabinets!

I think most folks that have insulated the cabinets have used the Reflectix. I plan to do that soon!

[reubenray]

Originally Posted by MSHappyCampers

Don't think I've heard of anyone using anything that thick. It would take up a lot of space in the cabinets!

I think most folks that have insulated the cabinets have used the Reflectix. I plan to do that soon!

Is this what you are referring to? If so how is it installed? We have moved our food over to the cooler side to keep the heat away from it.

Shop Reflectix R21 16-in x 25-ft Unfaced Reflective Roll Insulation at Lowes.com

[336muffin]

I have used Reflectix in ALL the overhead cabinets and all lower cabinets as well. Colsets, chest of drawers in bedroom and kitchen. This simple, cheap and easy install has made a difference that is worth it. If you oversize your cuts by a inch it will self support. If it does sag we used a few thumbtacks. Do the big spaces first and work down so to use material better.

[336muffin]

Originally Posted by reubenray

Is this what you are referring to? If so how is it installed? We have moved our food over to the cooler side to keep the heat away from it.

Shop Reflectix R21 16-in x 25-ft Unfaced Reflective Roll Insulation at Lowes.com

Yes that is it but we bought 4ft x 25ft

[MSHappyCampers]

Originally Posted by reubenray

Is this what you are referring to? If so how is it installed? We have moved our food over to the cooler side to keep the heat away from it.

Shop Reflectix R21 16-in x 25-ft Unfaced Reflective Roll Insulation at Lowes.com

Yep, that's it! Great stuff with a lot of uses! You can use something like RV Goop to stick the pieces in place, or some folks staple it!

[CLIFFTALL]

I saw Muffins installation at a rally and copied it . It worked great and didn't take up a lot if room at all.

[bdpreece]

I used 1/2" insulation board R-Tech 1/2 in. x 4 ft. x 8 ft. R-1.93 Insulating Sheathing-320810 - The Home Depot

I cut it about a 1/4 inch larger than the area I was insulating and pushed it in at an angle forcing it to compress as I put it in place on the top of the cabinets. I then cut the back pieces again about 1/4 inch larger than the area put the top against the back wall and forced the bottom into the back wall. They have been there about a year now and have not fallen out yet.

[MSHappyCampers]

Originally Posted by bdpreece

I used 1/2" insulation board R-Tech 1/2 in. x 4 ft. x 8 ft. R-1.93 Insulating Sheathing-320810 - The Home Depot

I cut it about a 1/4 inch larger than the area I was insulating and pushed it in at an angle forcing it to compress as I put it in place on the top of the cabinets. I then cut the back pieces again about 1/4 inch larger than the area put the top against the back wall and forced the bottom into the back wall. They have been there about a year now and have not fallen out yet.

Brian, only problem with that is the R-Value. It is only 1.93. The Reflectix R-Value is R3 to R21, depending on application.

[LadyFitz...]

Originally Posted by MSHappyCampers

Brian, only problem with that is the R-Value. It is only 1.93. The Reflectix R-Value is R3 to R21, depending on application.

The realistic minimum R-value for Reflectix is actually more like R1.2. The only way to get higher R-values from reflective insulation (technically, it is a radiant barrier) is to have a vented air gap on both sides of the radiant barrier ranging from 3/4" to 1 1/2" or more. The higher values are actually an assembly R-value. The higher R-values claims for radiant barriers have been a huge scam that the Feds have only recently started cracking down on.

[MSHappyCampers]

Originally Posted by LadyFitz...

The realistic minimum R-value for Reflectix is actually more like R1.2. The only way to get higher R-values from reflective insulation (technically, it is a radiant barrier) is to have a vented air gap on both sides of the radiant barrier ranging from 3/4" to 1 1/2" or more. The higher values are actually an assembly R-value. The higher R-values claims for radiant barriers have been a huge scam that the Feds have only recently started cracking down on.

I would assume that the R-Value with no air gap would be the R3 that they show. where do you get the R1.2 figure?

[aauummm]

Originally Posted by MSHappyCampers

I would assume that the R-Value with no air gap would be the R3 that they show. where do you get the R1.2 figure?

Actually the R value with no air gap is 1.1 per layer according to Reflectix website (scroll down to the very last line at the bottom of the page). I'll go with the foam board insulation that has an R4 for 3/4 in thick.

About Reflective Technology | What About R-values?

Stay Away from Foil-Faced Bubble Wrap | GreenBuildingAdvisor.com

In places where I've got the space, I may go with this R-6 stuff:
Rmax Thermasheath 3 R-6 1 in. x 4 ft. x 8 ft. Polyiso Rigid Foam Insulation Board-787264 - The Home Depot

[LadyFitz...]

Originally Posted by aauummm

Actually the R value with no air gap is 1.1 per layer according to Reflectix website (scroll down to the very last line at the bottom of the page). I'll go with the foam board insulation that has an R4 for 3/4 in thick.

About Reflective Technology | What About R-values?

Stay Away from Foil-Faced Bubble Wrap | GreenBuildingAdvisor.com

That covers it better than I could. Thanks for chiming in!

[MSHappyCampers]

Originally Posted by aauummm

Actually the R value with no air gap is 1.1 per layer according to Reflectix website (scroll down to the very last line at the bottom of the page). I'll go with the foam board insulation that has an R4 for 3/4 in thick.

About Reflective Technology | What About R-values?

Stay Away from Foil-Faced Bubble Wrap | GreenBuildingAdvisor.com

Actually in places where I've got the space, I may go with this R-6 stuff:

Rmax Thermasheath 3 R-6 1 in. x 4 ft. x 8 ft. Polyiso Rigid Foam Insulation Board-787264 - The Home Depot

Thanks, that's good info! I'm still wondering though if this might be the best thing to insulate the back wall (next to the outside RV wall) of inside storage cabinets. I don't want to use the thick foam insulation.