How much insulation to add to refrigerator ?

[Warren]

I am building cabinets for my kitchen and have a RV propane/120volt
Dometic 7732 refrigerator that will fit inside an 3/4 pine BC plywood
cabinet (top/sides and bottom/ I have fashoned an airtight plywood
chimney at the rear for venting to the outside. Should I add additonal
insulation to the sides and bottom of the cabinet or not? The cabin is
empty and gets quite hot during the summer months when we are not there.
Or should I just allow the cabin to vent by leaving a high window open
and installing a floor vent for intake of cooler air from under the
cabin? The cabin is 8ft off the ground on pilings.
Whats do you think? I plan on leaving the frig going 24/7/365.
I was thinking of building a cover of some type to install over the door
when we leave.
Thanks for any and all feed back.
Offgridman

 

[George Ghio]

I am building cabinets for my kitchen and have a RV propane/120volt
Dometic 7732 refrigerator that will fit inside an 3/4 pine BC plywood
cabinet (top/sides and bottom/ I have fashoned an airtight plywood
chimney at the rear for venting to the outside. Should I add additonal
insulation to the sides and bottom of the cabinet or not? The cabin is
empty and gets quite hot during the summer months when we are not there.
Or should I just allow the cabin to vent by leaving a high window open
and installing a floor vent for intake of cooler air from under the
cabin? The cabin is 8ft off the ground on pilings.
Whats do you think? I plan on leaving the frig going 24/7/365.
I was thinking of building a cover of some type to install over the door
when we leave.
Thanks for any and all feed back.
Offgridman

Go for it.

 

[Bughunter]

I would consider 1" of rigid polyicocyanurate (sp?) around the fridge.

It has a higher "R" factor, and is much less combustable than styrofoam.
I would "not" use stryofoam because it is highly combustable.

Make provisions in your design for backside access for periodic cleaning and
maintenance.

We had an old Servel in our camp that ran 24/7/365. Kitchen grease combined
with dust and cobwebs accumulated behind the unit, and caused a smoldeing
fire. Fortunately, the fire was confined to the area just behind the fridge,
and did not spread to the rest of the house, but the smoke damage was
considerable. What a mess! It took months until the smell was gone.

It might have been a whole lot more of a problem if there had been
combustables (like styrofoam) nearby.

I'd also line your plywood chimney completely with sheet metal.

I think I'd also consider an inlet at the back of the fridge (floor)
instead of depending upon an open window. Make it squirrel and rodent proof
with some 1/4" heavy wire mesh. A rodent nest could be another source of
fuel for a fire.

I wouldn't bother with a door panel.

my $.02

 

[m Ransley]

A plywood chimney sounds like it wont pass code and will be dangerous
Yes insulate 1-4 inches use the R 7.2 foamboard. refrigerators come wth
apx R 10 to 15 R , but your ceiling should have R35 in zone 5 ? More
will help.

 

[someonesimple]

I am building cabinets for my kitchen and have a RV propane/120volt
Dometic 7732 refrigerator that will fit inside an 3/4 pine BC plywood
cabinet (top/sides and bottom/ I have fashoned an airtight plywood
chimney at the rear for venting to the outside. Should I add additonal
insulation to the sides and bottom of the cabinet or not? The cabin is
empty and gets quite hot during the summer months when we are not there.
Or should I just allow the cabin to vent by leaving a high window open
and installing a floor vent for intake of cooler air from under the
cabin? The cabin is 8ft off the ground on pilings.
Whats do you think? I plan on leaving the frig going 24/7/365.
I was thinking of building a cover of some type to install over the door
when we leave.
Thanks for any and all feed back.
Offgridman

I have the same frig in my cabin. Your suggested installation does not
appear to lend itself to easy inspection / repair. And if your cabin is
like mine - critters get inside and do all sorts of nasty stuff.... Like
build nests near warm areas in the winter........or chew piezo wires.... or
crap on the burner. Under certain conditions soot can build up around the
burner and needs to be cleaned.

I insulated top, bottom and sides with 1 1/2" polyisocyanurate and covered
the exposed insulation with concrete board [I figured drywall might get
pretty dinged up over time]. It uses about 4 lbs of propane a week - which
is a little less than a gallon. I think this is pretty good effeciency all
things considered. And cold beer IS important.

I riveted additional sheet metal to increase the chimney height to a few
inches above the frig and insulation - and placed it at counter height on a
shelf with heavy duty roller bearing draw glides [the double slide, full
extension type] - it's kinda like the upper half of a broom closet. The gas
connection is flexible stainless steel - so the unit can roll out without
kinking the gas line - and I can get a look-see whenever I want without any
heartburn.

It's on an outside wall. In the ceiling I installed a short piece of metal
dryer duct venting into the roof overhang. I finished both terminations
with soffit louvre vents. The distance between the top of the unit chimney
and the ceiling is about 18" and not directly connected. This allows a
little air to come in and a little exhaust to go out. I did some CO tests
after installation and never got a positive reading. I've never had a flame
out due to insufficient oxygen.

 

[Bughunter]

Sounds like a winning design.

 

[Warren]

A plywood chimney sounds like it wont pass code and will be dangerous
Yes insulate 1-4 inches use the R 7.2 foamboard. refrigerators come wth
apx R 10 to 15 R , but your ceiling should have R35 in zone 5 ? More
will help.

I guess my description was not very good. The chimney is really just a
drafting aid for the exhaust gases. The unit is rated for zero clearance
on all sides. The sheet metal lining is a good idea. I will have upper
and lower louvered vents through the back wall to allow for intake and
exhaust. The installation manual says that the vents will allow for
enough room for cleaning etc. The refrigerator seals with foam strips to
the front of the cabinet to isolate the cabin interior. I have carefully
caulked and sealed the cabinet and draft chimney. I will add the foam
board to the sides as suggested. Thanks for the feedback.
Offgridman