condensation in the shop

[Andrew Seemann]

Keep on mind that you also don't want to power vent in a bunch of warm moist air when your machinery is cold. You want to keep the moisture away from the machines, and if it is more humid outside than inside, venting makes the problem worse rather than better.

[Jon McElwain]

I lived in SE Alaska for 14 years and had a shop there. It is a rain forest - always wet and cold. I ran a dehumidifier most of the year and it seemed to manage the humidity pretty well. I had the occasional rust spot from a spill, but I don't think that I ever had condensation while it was running.

Someone said it above, but the propane combustion is going to release H2O into the air. I would get a different heat source, or get a radiant tube heater fired with propane that is vented outdoors. You'll always fight condensation with that type of heater in there.

[Bill Dufour]

In a metal working shop the classic answer is a light bulb in the machine base and a blanket thrown on top. Of course no big fire hazard with no sawdust. My metal working lathe had a condensation problem because being so heavy it takes a much longer time to warm up above the dew point as temps change in the shop. I ended up putting two goldenrod heaters in the base.
I may just use an electric blanket on my milling machine.

[Ronald Blue]

You don't need much heat. I may not get as cold as you do but where I am is close. A few years ago when propane went out of sight on cost I used a couple electric heaters to maintain a steady temperature. Two 1500 watt heaters will surprise you. My current shop is 24 by 30 and well insulated. I have never had any moisture issues unless they were of my own creation. Even when the temperatures fluctuate greatly the shop changes slowly. I don't have any ventilation in the shop. I keep the thermostat about 50 if I am not using the shop. Humidity is about 50% at this time but overnight will go back up into the 80% range. Just my two cents. Good luck on a solution.