Installing heat dump in uninsulated Garage, antifreeze or?

[Dune]

Per advice of BeGreen, I am installing a heat dump. I have a small modine heater. I would like to kill two birds with one stone, and be able to heat the garage when I want to. My options are, antifreeze my whole system or, mount the modine in the cellar, duct the hot air out to the garage with an air zone. I can handle the sheetmetal work, and I have an air zone, but return air is an issue. If I antifreeze my system, the installation is simple, but I don't know if antifreeze is a good thing if it could be avoided. What do you people think?

 

[sdrobertson]

I would avoid the antifreeze at all costs. Its expensive, and doesn't transfer heat nearly as well as water and your using it for a heat dump in an emergency. Just circulate a small amount of water to keep it from freezing and install it in the garage as I'm assuming that its insulated because you said you could have heat when you were in it.

 

[Dune]

No, it is not insulated.
That is what I thought about the antifreeze. I guess I will install it in the basement and duct the heat out to the garage.
Thanks.

 

[stee6043]

For a few bucks you could rig up a timer relay to run the pump on your modine once every hour or two to prevent freezing. Might save you some headaches and enable you to get the most out of your garage heater...

 

[Dune]

For a few bucks you could rig up a timer relay to run the pump on your modine once every hour or two to prevent freezing. Might save you some headaches and enable you to get the most out of your garage heater...

Thanks for the idea. Something for me to think about.

 

[cricco]

I did the same thing. I just keep my garage (insulated) at 55 degrees all winter.

 

[Wood Pirate]

I have been looking for a little modine to do the same thing. How many BTU's is the modine you are using?

How about a piece of electric heat trace with a thermostat that would give it a bit of heat? You could wrap it around the inlet and outlet which should keep it warm enough not to freeze?

 

[Tony H]

Heat transfer is better with pure water than the glycol mix but the percentage of glycol makes a big difference so rather than a 50/50 mix a weaker mix of say 25/75 would offer protection but not lower the transfer rate as much. The other idea of using thermostatically controlled heat tape and maybe a small pump to move the water would work but use some a/c and not require you to use glycol in the system.

 

[Dune]

I have been looking for a little modine to do the same thing. How many BTU's is the modine you are using?

How about a piece of electric heat trace with a thermostat that would give it a bit of heat? You could wrap it around the inlet and outlet which should keep it warm enough not to freeze?

Checked the unit, no idea, it doesn't list BTUs anywhere. It is very small, about 12"x12", fed with 3/4" pipe. The blower motor is 1/25th hp.

The price was perfect though.(free)

I just installed it in the basement as a heat dump only, I have a nice litle heat exchanger and as soon as I am given a cirulator that works, I am going to move it to the garage. I will only antifreeze that side of the HX, less than a gallon. The only disadvantage to this plan is needing another circ, but my brother should get one for me before December, when I will start wanting heat in the garage.

 

[peakbagger]

A general comment about used Modine type units is that there are a lot of them available that leak and its not worth the hassle to fix them. Pressure test them before you plumb them up. I went through a couple of "good when we took it out" units and at least three of them leaked when I tested them. All I can suspect is that they dont store well dry. Either that and the leak and get replaced, then set aside for future repairs that never happen.