Ecomodding my fridge

[AllenK]

I did reduce power consumption of my old fridge down to 50% by insulating it myself. Since one year it does run flawlessly. Have a look at my page for details, measurements i took or for comments:

Make your old fridge green by insulating it

Allen

[Cd]

It's not for everyone, but I have been very pleased with the mod I did to the 'fridge in my apartment.
I bought a temperature controlled power switch and have it in my freezer.
I've used it like this for over a year.

[AllenK]

Originally Posted by Cd

It's not for everyone, but I have been very pleased with the mod I did to the 'fridge in my apartment.
I bought a temperature controlled power switch and have it in my freezer.
I've used it like this for over a year.

Did you measure the energy savings by your measurements?
And why did not the thermostat of the fridge do that job?

Greeting. Allen

[pete c]

I have another thought regarding fridge efficiency.

During the summer your fridge is basically a space heater in an area you don't want heated and in many cases, use power to cool. This is horribly inefficient.

the solution is to figure out a way to vent that heat outside.

My fridge has its evaporator (or is it condensor, I always screw the two up) on its rear wall. My thought is to enclose this is an airtight box made of some sort of thin insulated board that you can buy for next to nothing at HD. Half inch thick or so should do. Use duct tape to hold the seams together and make it air tight. Place an input duct near the floor and an exhaust duct near the top. You could make these ducts out of the same material. Box out the sheet rock on an exterior wall so that when the fridge is pushed against the wall, it fits into these holes. On the outside wall, you would have to trim it out with some sort of ventilated cover.

I believe there would be sufficient airflow thanks to the natural chimney effect when the fridge is running.

During the summer, you'd get rid of that unwanted warm air. During the winter, you would be venting away wanted heat, but, the fridge itself should run quite a bit more efficiently due to the cold outside air running across the coils.

An even better solution for cold temps would be a figure out a way to pipe that cold air directly to the fridge. I actually like Pioslaw's solution of placing frozen water bottles inside. So simple it is brilliant. I will do this next winter.

Another thought I had was to figure out a way to plumb some sort of heat exchanger to use cold potable water on it's way to the water heater. There are a few potential problems such as what do you do when there is not enough hot water demand to carry away all that heat, but, there are solutions. Also, I am not sure how a fridge's coil would like being submerged in the heat transfer liquid, most likely water.

[Piwoslaw]

Originally Posted by pete c

My thought is to enclose this is an airtight box made of some sort of thin insulated board that you can buy for next to nothing at HD. Half inch thick or so should do. Use duct tape to hold the seams together and make it air tight. Place an input duct near the floor and an exhaust duct near the top.
[...]
I believe there would be sufficient airflow thanks to the natural chimney effect when the fridge is running.

How about a chimney on the back of the fridge? - EcoRenovator.org

Originally Posted by pete c

During the summer, you'd get rid of that unwanted warm air. During the winter, you would be venting away wanted heat, but, the fridge itself should run quite a bit more efficiently due to the cold outside air running across the coils.

Why not disconnect the duct from the hole in the wall and have the warmer air help heat your kitchen?

Originally Posted by pete c

An even better solution for cold temps would be a figure out a way to pipe that cold air directly to the fridge.

Why pipe it? If the outdoor temp is in the right range, then just unplug the fridge, pack your stuff in a basket and put it outside. You can't get lower than using no energy.

Originally Posted by pete c

I actually like Piwoslaw's solution of placing frozen water bottles inside. So simple it is brilliant. I will do this next winter.

Not frozen water, just plain liquid water. Only add thermal mass (and decrease the volume of unused space), no phase-change stuff. Over at EcoRenovator, Daox did an experiment with putting water jugs outside to freeze and then moving them to the fridge. Yes, it reduced the refrigerator's energy consumption slightly, but in essence it was removing heat from the house, so the heating system had to work a little harder to make up for that.

Originally Posted by pete c

Another thought I had was to figure out a way to plumb some sort of heat exchanger to use cold potable water on it's way to the water heater.

This has been done, but I'm not sure if the gains are worth the effort.

The bottom line is: A refrigerator is often thought of as a space heater. This is true, but not to the extent that most people think. The radiator coils get warm, but most of that is the kitchen's heat which permeated through the insulation into the fridge. The only extra heat comes from the energy used to run the compressor (and the lightbulbs). So if you move that heat outdoors, you generally have a heat pump, specifically an air conditioner. You are pumping your house's heat outdoors. Good during cooling season, bad otherwise.

Now, since the only new heat produced by a refrigerator comes from running the compressor, then it would be best to reduce compressor use (or get a more efficient, scroll type compressor). This can be done by adding insulation - the longer it takes a given amount of heat to seep into the fridge, the less often the compressor will be needed.

Once you have better insulation and/or added thermal mass, you can put it on a timer to keep it from turning on for longer periods, eg at night or during the day when no-one is at home. You should keep track of the temperature inside, though, to make sure nothing spoils.

[pete c]

Some interesting points, Pioslaw.

I think the one idea that definitely makes sense is venting the warm air outside during the warm months. Using the cold outside air to cool the coils in the winter is debatable because of its net effect on cooling the entire house. My gut feeling is that you are probably best off to just seal up the wall when it gets cold enough to run the heat. There is one problem I see with the summer mode of operation. If it is very hot outside, drawing the cooling air from outside means it will have to run more. A possible solution is to continue the chimney down through the floor so you use cooler basement air for cooling. Of course this means that the basement gets warmer.

[ecomodded]

With my fridge , 7 year old GE ,all i can do is add insulation, I am in the process of insulating it, with the insulation in the inside and some on the outside.
The bottom inside of the fridge, nearest the mini fan cooled coil pack and the compressor, will get the thickest insulating.
The plans is to tape the seams and cover the inside foam with a hard washable surface.
I am going to enhance the air flow both in and out by making defined air channels,as it mixes now.

- Here's a tip for everyone -

Yesterday i turned my hot water heater down to a comfortable temperature,for use without the need of adding cold water.
I had enough of super heating the water just to add cold water to it.

[Piwoslaw]

Originally Posted by ecomodded

With my fridge , 7 year old GE ,all i can do is add insulation, I am in the process of insulating it, with the insulation in the inside and some on the outside.

You mean like this?


Two more suggestions for refrigerator efficiency:

1. Heat transfer through the walls (heat gain) is a function of temperature difference, so you can raise the inside temp slightly (sometimes fridges are set way too low) and/or lower the ambient temp. I'm not suggesting having your house's A/C works its pants off, but keeping the kitchen slightly cooler (leave a window slightly open at night with the doors closed), or moving the fridge to a cooler area. Like farther away from the stove/range, dishwasher, sunny window, or other heat sources. I once saw a refrigerator placed so that the heating system's vent was blowing hot air at it all winter, and the sun was shining on it for 1-3 hours daily, year round
2. 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.

[ecomodded]

They started putting the condenser coils below next to the compressor ,on the newer fridges.

It has a fan that sucks cold from under one side of the fridge over the condenser coils and exhaust's directly onto the compressor, cooling it at the same time.
From that point it is forced back out the other side of the bottom.
I need to insulate between the condenser/ compressor and crisper floor. The back of the fridge where usually the condenser wrack would reside is smooth sheet metal,which stays cool, as does the top of the fridge.
When i finish with the insulation job, ill post pictures.
Tomorrow i am off to the Building material recyclers to get some thick foam insulation. I try to recycle when ever feasible.

[ecomodded]

[QUOTE=Piwoslaw;324226]You mean like this?



Haha NO ! But now im thinking about it ! LOL