On Nov 25, 10:20*am, Dave Garland wrote:
Red Green wrote:
Probably cost a fortune to make refrigs that could use piped in air from
outside. And the further south you are the longer the ROI breakeven.

Yes. *I've been thinking of doing that for the last 40 years. *It would
work best if you could build the refrigerator into the house (think
walk-in cooler, but smaller, or the undercounter fridges found in bars).
*You'd need a fan to circulate outside (cold) air in, and dampers to
close off from the outside, and a controller to regulate the dampers &
fan and switch to powered refrigeration when the outside temperature is
warmer than refrigerator-interior temperature. *Ditto for the freezer,
though even in Minnesota there isn't that long a period when outside
temperature stays below 0 degrees F. *(But outside air could be used to
cool the coils of the powered refrigeration and increase its
efficiency.) *For that (in Minnesota) you could avoid much of the
refrigeration energy for maybe 3 months, and get some unknown
improvement most of the rest of the year.

One side benefit is that if you're building the fridge, you're not
constrained to fitting insulation within a thin metal shell, you can
insulate as much as you want. *The dampers and the door would be the
parts that were harder to insulate.

But it does sound like a lot of work to accomplish.

Dave


About 25 years ago I read an article about the guy that built a
supreinsulated freezer with thermal mass in it. He used a heat pipe
to freeze it al winter and it wouel swing through the summer.

Wow this is a long ways from a door bell