Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Super efficient fridge

Cd · 06-26-2009, 04:24 PM

The amount of heat gain (or cold loss) is proportional to the surface area. So, what you want is a unit with the smallest surface area for a given volume. This would be sphere, but since they don't make spherical fridges, the closest thing is a cube, i.e. height, width and depth are the same.

So all things being equal, the 5 cubic foot model is more efficient than the 7 cubic foot one, since it has less surface area, and a smaller area within the freezer to cool ?
The 5 cubic foot model is sqare shaped, and the 7 cu.ft. model is more rectangular.

Next are the coils (the radiator, as Christ called it, since that's what it really is). A lot of new refridgerators have coils at the bottom, under the unit. This is bad, since the warm air rises off of the radiator straight onto the fridge. A radiator on the back of the unit is much better. (Recently I read a thread on convection, conduction, radiation, either here or on EcoRenovator, but I can't find it now.)

( Not much traffic at EcoRenovator, which is why I'm posting here.) I'll search for that thread as well.

So what are the coils buried within the walls of refrigerators and freezers ? Is this the same type of coil that you are talking about ? I notice that the sides of my mini-refrigerator get very hot. I insulated the walls of my minifridge with 1.5" thick styrofoam, yet it did nothing - it even seemed to increase the power useage at one point. I guess I was just sealing in all that heat.
Since coils can be mounted outside of the walls of the refrigerator, would it help the efficiency to rip out the coils within the walls and place them on top of something like my mini-fridge ? I was under the impression that the coils need to wrap around the walls of the 'fridge to extract the heat.

With a more powerful compressor, the on-time may even be below a minute, which isn't too healthy for it.

Can you please explain that last statement further ? So if I have the compressor kicking on for less than a minute, this might damage it ?

Last, placement. Make sure the unit isn't placed in a warm place, like next to a stove, oven, heating vent, or where the sun will shine on it. A basement with year-round cool temps is ideal.

I plan to place the chest freezer in my laundry closet, which has sliding doors and the right type of outlet. Would a small closet just trap in the heat generated by the fridge ? ( I should add that the closet is empty - so no washing and drying will take place there )

Hope that helps

( Very much so ! Thank you ! )

06-26-2009, 04:24 PM	#4 (permalink)
Cd Ultimate Fail Join Date: Feb 2008 Location: Austin,Texas Posts: 3,585 Thanks: 2,872 Thanked 1,121 Times in 679 Posts	The amount of heat gain (or cold loss) is proportional to the surface area. So, what you want is a unit with the smallest surface area for a given volume. This would be sphere, but since they don't make spherical fridges, the closest thing is a cube, i.e. height, width and depth are the same. So all things being equal, the 5 cubic foot model is more efficient than the 7 cubic foot one, since it has less surface area, and a smaller area within the freezer to cool ? The 5 cubic foot model is sqare shaped, and the 7 cu.ft. model is more rectangular. Next are the coils (the radiator, as Christ called it, since that's what it really is). A lot of new refridgerators have coils at the bottom, under the unit. This is bad, since the warm air rises off of the radiator straight onto the fridge. A radiator on the back of the unit is much better. (Recently I read a thread on convection, conduction, radiation, either here or on EcoRenovator, but I can't find it now.) ( Not much traffic at EcoRenovator, which is why I'm posting here.) I'll search for that thread as well. So what are the coils buried within the walls of refrigerators and freezers ? Is this the same type of coil that you are talking about ? I notice that the sides of my mini-refrigerator get very hot. I insulated the walls of my minifridge with 1.5" thick styrofoam, yet it did nothing - it even seemed to increase the power useage at one point. I guess I was just sealing in all that heat. Since coils can be mounted outside of the walls of the refrigerator, would it help the efficiency to rip out the coils within the walls and place them on top of something like my mini-fridge ? I was under the impression that the coils need to wrap around the walls of the 'fridge to extract the heat. With a more powerful compressor, the on-time may even be below a minute, which isn't too healthy for it. Can you please explain that last statement further ? So if I have the compressor kicking on for less than a minute, this might damage it ? Last, placement. Make sure the unit isn't placed in a warm place, like next to a stove, oven, heating vent, or where the sun will shine on it. A basement with year-round cool temps is ideal. I plan to place the chest freezer in my laundry closet, which has sliding doors and the right type of outlet. Would a small closet just trap in the heat generated by the fridge ? ( I should add that the closet is empty - so no washing and drying will take place there ) Hope that helps ( Very much so ! Thank you ! )