Ecomodding my fridge

[Christ]

If you've got the "under the fridge" heater/pump setup, one thing you can do is move the fridge to an area of direct airflow, such as near a vent in the floor. The flow will keep the room air moving under the fridge and keep the heat from penetrating into the food compartment.

Likewise, a small computer fan can handle that flow requirement and burns mW, which, since the pump isn't heating the fridge compartment, could nullify some of the power use of the fridge as well, while providing that little bit of heat energy to the house during cooler months, also helping to negate the need for heat by that little bit.

Passivhaus concept.

[jakobnev]

I had already added insulation to it erlier, but the thermostat is dying so it started freezing my food.

I started with 50% cycle and got avg. power down from 68w to 45w.

It held the temp below 8C so now i'm going to try 43% cycle.

[radioranger]

Great topic, i just threw a nice blanket over the top of the fridge after laying a few towels on top , also moved it away from the wall a bit more, and blocked off the radiator right at the base of the wall, if the blanket gets a bit dusty , pretty easy to wash, might be a cool thing for a sewing job, make a quilt to cover the fridge every night or when at work, will report back after this months bill comes in as my house is all LED lit and bill runs around 35 $ now.

[AllenK]

its running without issues. Power consumption down to 50% = 135kWh per year. Have a look here: Make your old fridge green by insulating it

[Cd]

Reviving a long dead thread with some questions.
Is there a rating for refrigerator comressor motors that tell their efficiency ?
I know that you can look at the EPA Energy Star Kwh used and divide by the cubic footage, but I would think this does not really show the efficiency of the compressor itself, since some refigerators are insulated differently.

Is it possible to safely remove a compressor motor and place it somewhere besides UNDER the fridge ??

I'd like to take a medium size refigerator and lay it on its' back to make a chest freezer.

Can you do this with refrigerant in the unit and shut it off and reconnect it again ?

Correct me if I'm wrong, but I got the impression that adding insulation to the OUTSIDE of a refrigerator is not a good idea because of the coils in the walls of the refigerator.
Can you please remind me of what these coils in the walls do ? ( And why adding insulation to the outside is not good )
Would it work better to get a 12 cu ft refrigerator and add cork or coroplast layers on the INSIDE of the refigerator ?
You could also use layers of freezer packs in the walls of the coroplast.

This would of course create a smaller useable space inside. I'm aware of that. I'm just wondering how this all works.

I have read thar a frig that is packed full of food is more efficient than one that is empty, but I also recall getting the impression that a freezer that needs to be deiced because it is completely packed with ice is less efficient.
I'm confused.

I haven't read through all the threads again.
What was the Kwh / Cu ft record that any of you got on your frig mods ?

Lastly, I'd like to ask why chest freezers are not built to be used horizontally.
What I mean by that, is that unlike freezers at the grocery store, commercial chest freezers are square - not a rectangle.
This means you have to stack food, rather than lay it out horizontally.

I'd like to build a super cheap DIY solar refigerator / freezer.

[cRiPpLe_rOoStEr]

Originally Posted by Cd

Is it possible to safely remove a compressor motor and place it somewhere besides UNDER the fridge ??

I'd be more interested on finding another location for the coils, such as above the fridge in order to allow convection naturally increase heat rejection, as they work in a way similar to the condenser of an air conditioner. Just like the split air conditioners now have the condenser mounted remotely.

Correct me if I'm wrong, but I got the impression that adding insulation to the OUTSIDE of a refrigerator is not a good idea because of the coils in the walls of the refigerator.

If it had more clearance from the walls of the refrigerator, adding insulation between the walls and the coils would make more sense than doing it inside the refrigerator.

I have read thar a frig that is packed full of food is more efficient than one that is empty, but I also recall getting the impression that a freezer that needs to be deiced because it is completely packed with ice is less efficient.
I'm confused.

It's always better to leave some space for the air circulate through convection, even if you pack the fridge up near to its full volume.

[Randy]

Originally Posted by Cd

I'd like to take a medium size refigerator and lay it on its' back to make a chest freezer.

Compressors rely on gravity for lubrication, so they should be oriented base-down. I don't think this would work well compared to a chest freezer.

Originally Posted by Cd

Correct me if I'm wrong, but I got the impression that adding insulation to the OUTSIDE of a refrigerator is not a good idea because of the coils in the walls of the refigerator.
Can you please remind me of what these coils in the walls do ? ( And why adding insulation to the outside is not good )

You can use energy to move heat, but you can't just eliminate it. The outside coils dissipate the heat removed from the inside. Note that they aren't always in the outside walls: they're often in outside radiators or fan-cooled condensers.

Originally Posted by Cd

I have read thar a frig that is packed full of food is more efficient than one that is empty, but I also recall getting the impression that a freezer that needs to be deiced because it is completely packed with ice is less efficient.

In general the thermal loss is the same for the same internal temperature, so if everything was equal these wouldn't matter. The "packed full" idea is that the refrigerator is designed to run longer than just cooling down the air inside it. Water has an enormous thermal capacity compared to air so a full refrigerator has a longer run and off time, minimizing the inefficient start-stop parts of the cycle.

An iced-up freezer is less efficient because the ice insulates the evaporator. The refrigerator works to cool the evaporator, so when iced up it's working to cool far below freezing. The "packed full" effect is much, much smaller than this.

[cRiPpLe_rOoStEr]

Originally Posted by Randy

An iced-up freezer is less efficient because the ice insulates the evaporator. The refrigerator works to cool the evaporator, so when iced up it's working to cool far below freezing.

What a PITA it was to defrost a fridge.

[Circlotron]

Originally Posted by Piwoslaw

Put a small fan under the rear coils, blowing upward whenever the compressor is on. This improves the heat exchange efficiency of the radiator, and helps the warm air leave the rear wall faster.

This ^
Got our first fridge in 1980 and while the compressor was running the power consumption was 240 watts. An hours running meter showed long term average it ran 60% of the time. By 2002 I got the urge to do something about it. Put a pair of 90mm computer fans at the bottom of the coils, aiming upward and came on with the compressor. Also inside, a single 90mm fan aimed at the centre of the flat plate evaporator about 15mm away and running continuously. Like a fan forced oven but cold. Temp was set at 4 deg C. With these mods the compressor duty cycle dropped from 60% to 31%. Only snag was the freezer was now not cold enough to keep ice cream hard. Very soft and soggy. Didn't measure the temp in the freezer. Kept it like this till late 2019 when we finally put it out because there was a number of water leaks because of cracks in the plastic interior. One interesting point - the interior fan was a ball bearing type and had run continuously for something like 150,000 hours and was still perfectly good. Low temps definitely makes for long bearing life.