Water heating idea

[RU482]

Would there be any harm done to the compressor/cooling system of my refrigerator and/or deep freeze if I created a heat exchanger, cycling water headed for the inlet side of my hot water heater?

Wold the refigerator run more efficiently?

 

[CycloWizard]

In principle, it could increase the efficiency of both devices. However, in practice, the equipment you would need to make it happen would more than offset any financial benefits you would see in your lifetime.

 

[spigot]

It would work well as far as increasing the efficiency of your fridge and freezer, especially if the water was below room temp. But, if you're not drawing any hot water, and the flow stop while your fridge is running, it's just going to continue to heat the water around the condenser until you fridge stops working...you'd have to have continuous flow.

 

[QuantumPion]

Such a setup would be called a feedwater heater. However, as stated above, the efficiency you would gain would be practically zero, and the cost of the equipment would be substantial.

 

[jagec]

Originally posted by: spigot
It would work well as far as increasing the efficiency of your fridge and freezer, especially if the water was below room temp. But, if you're not drawing any hot water, and the flow stop while your fridge is running, it's just going to continue to heat the water around the condenser until you fridge stops working...you'd have to have continuous flow.

Your fridge is normally surrounded by air, which is a far worse conductor than water. If there is no flow in the water pipes, the water will warm up, which will warm the (presumably metal) pipes in which it's contained, which will then discharge that heat to the air. Unless you're wrapping the entire thing in styrofoam (and maybe not even then), you are NOT going to blow your fridge out.

 

[DrPizza]

Your idea really isn't that bad. There are already water cooled refrigeration units. I don't see why you couldn't tie into such a system and replace it with cooler fresh water whenever there was a demand for more water in your water heater.

However, for the typical refrigerator in a home, I'd think the return on investment would be marginal, if that. It wouldn't make sense to do so during the colder months when waste heat from the fridge simply supplements the heat produced by your home's heating system.

 

[CycloWizard]

Originally posted by: jagec
Your fridge is normally surrounded by air, which is a far worse conductor than water. If there is no flow in the water pipes, the water will warm up, which will warm the (presumably metal) pipes in which it's contained, which will then discharge that heat to the air. Unless you're wrapping the entire thing in styrofoam (and maybe not even then), you are NOT going to blow your fridge out.

This could still cause the compressor to overheat. The water and piping would essentially act as insulators by forming a thermal boundary layer and preventing the same degree of natural convection away from the compressor, significantly decreasing the heat transfer rate and increasing the temperature at the compressor.

 

[NeoPTLD]

There's a practical installation that captures heat from shower drain with a heat exchanger and warm up the water going into the water heater. Much much more effective financially.