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Enyin · 03-19-2003, 03:12 PM

When I read the title of this thread at first I thought maybe you were going to try to use the entire fridge as a res - that would be an interesting project

Some mini fridges cool by having the evaporator coil built into the lining of the fridge - so the coil is not exposed at all. I wonder if anyone has ever tried this - pull off the door and take a look inside, see if some silicone could be used to make the fridge water tight, now you could either just turn the fridge on it's side (not sure if this would work, compressors and any accumulators / receivers normally need to remain upright I think) or cut an access door / hatch / port in the top. now place your eheim or whatever pump in the fridge, run you lines out through your access opening and fill the fridge with water!

You could even replace the door with sheet of lexan and seal it on...that would look spiffy!
Basically though, the total size of the res now measured in gallons might offset the average fridge's inability to cool water that is moving too quickly through a small amount of surface area inside the fridge --- and a good amount of water would be in direct contact with the fridge's cooling surfaces.

The question is, can the fridge keep up with a continuous heat load - an eheim pump I think is 20w of heat - the cpu can vary alot depending on your frequency and voltage, I think when I calculated my athlon xp 1600 at 1.85 volts and 1.66ghz it came out to around 95w
1 watt = 3.413 btu/hr. So in the above scenario you would need approx 400 btu/hr disregarding any other heat losses to break even. However, bring in the capacity of your cooling system and it gets more complicated - 1btu is the amount of energy required to raise 1 pound of water 1 degree F. Keeping in mind that water weighs about 8.3 lbs per gallon lets assume with your mini fridge is 2.5 cu ft or 18.7 gallons -- this is 155 lbs of water. So in theory it seems that our hypothetical system would raise the temp of this res without any cooling by about 2.5 degrees F per hour - now bring in the power of your active cooling and reduce from there. You can see that it would take a long time for your system to heat up - if you don't run 24/7 you probably will do fine with a setup like this, your downtime would give the fridge a chance to cool the water back down.

Experts feel free to tear my theories apart - I'm just a novice and very interested in learning more about calculations like this.

03-19-2003, 03:12 PM	#11
Enyin Cooling Neophyte Join Date: Feb 2003 Location: NJ, USA Posts: 22	resevoir When I read the title of this thread at first I thought maybe you were going to try to use the entire fridge as a res - that would be an interesting project Some mini fridges cool by having the evaporator coil built into the lining of the fridge - so the coil is not exposed at all. I wonder if anyone has ever tried this - pull off the door and take a look inside, see if some silicone could be used to make the fridge water tight, now you could either just turn the fridge on it's side (not sure if this would work, compressors and any accumulators / receivers normally need to remain upright I think) or cut an access door / hatch / port in the top. now place your eheim or whatever pump in the fridge, run you lines out through your access opening and fill the fridge with water! You could even replace the door with sheet of lexan and seal it on...that would look spiffy! Basically though, the total size of the res now measured in gallons might offset the average fridge's inability to cool water that is moving too quickly through a small amount of surface area inside the fridge --- and a good amount of water would be in direct contact with the fridge's cooling surfaces. The question is, can the fridge keep up with a continuous heat load - an eheim pump I think is 20w of heat - the cpu can vary alot depending on your frequency and voltage, I think when I calculated my athlon xp 1600 at 1.85 volts and 1.66ghz it came out to around 95w 1 watt = 3.413 btu/hr. So in the above scenario you would need approx 400 btu/hr disregarding any other heat losses to break even. However, bring in the capacity of your cooling system and it gets more complicated - 1btu is the amount of energy required to raise 1 pound of water 1 degree F. Keeping in mind that water weighs about 8.3 lbs per gallon lets assume with your mini fridge is 2.5 cu ft or 18.7 gallons -- this is 155 lbs of water. So in theory it seems that our hypothetical system would raise the temp of this res without any cooling by about 2.5 degrees F per hour - now bring in the power of your active cooling and reduce from there. You can see that it would take a long time for your system to heat up - if you don't run 24/7 you probably will do fine with a setup like this, your downtime would give the fridge a chance to cool the water back down. Experts feel free to tear my theories apart - I'm just a novice and very interested in learning more about calculations like this.