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View Full Version : Moisture control in a shop revisited again



MichaelP
01-03-2010, 12:55 PM
Anyone ever tried using infrared bulbs in an attempt to keep machine surfaces at a slightly higher temperature? Although I have serious doubs about efficiency of such approach (limited power to heat huge amount of metal), I'd very interested to hear opinions and experience-based feedback.
We can expand into natural gas IR heaters, etc. Again, not to heat the space, but just keep the machines warmer.

Midwestern cold and high humidity severely affect our anti-rust battle outcomes, but keeping garage heated 24/7 will cost a small fortune for an average home shop hobbyist. Warm seasons are easier in this respect since a dehumidifier can be used quite effectively. Cold doesn't allow its use, and as soon as you start heating your garage to prepare for working there, a severe condensation results (cold machines/warm air).

RKW
01-03-2010, 01:04 PM
Don't forget that heat generated by flame causes more moisture (and CO2) ... Its a vicious cycle! I can't wait for spring myself, or at least more reasonable temperatures. How do you Canadians do it?!


Anyone ever tried using infrared bulbs in an attempt to keep machine surfaces at a slightly higher temperature? Although I have serious doubs about efficiency of such approach (limited power to heat huge amount of metal), I'd very interested to hear opinions and experience-based feedback.
We can expand into natural gas IR heaters, etc. Again, not to heat the space, but just keep the machines warmer.

Midwestern cold and high humidity severely affect our anti-rust battle outcomes, but keeping garage heated 24/7 will cost a small fortune for an average home shop hobbyist. Warm seasons are easier in this respect since a dehumidifier can be used quite effectively. Cold doesn't allow its use, and as soon as you start heating your garage to prepare for working there, a severe condensation results (cold machines/warm air).

MichaelP
01-03-2010, 01:06 PM
Open flame or no exhaust for a gas IR heater are out of question, of course.

Flash319
01-03-2010, 01:24 PM
For the last few years I had been using a salamander (propane burner). This was the worst thing for condensation. I got a sealed burner propane furnace from the classifieds for a $100. This has been the best thing I have done to the shop. I put no ducts on it and just have it suck and blow straight from the furnace. Man it works very good and next to no condensation on the machines (always have some because of the temperature of the machines but way better then open burning). It also only takes about 15 min to heat up to 10C from -20C. It is a 80,000 btu furnace and the shop is 16X25.

Just my 2cents

steve45
01-03-2010, 01:27 PM
Warmer air will hold more moisture. I'd try a dehumidifier first.

Carld
01-03-2010, 01:56 PM
Ya'll could have solved all your heat problems by going Earth bermed like I did. My shop stays about 50 degF year round unless it gets real hot or real cold. Then it will only get to about 65 in the hot summer and 45 in the cold winter. I have a heat pump in the shop and use a dehumidifier to keep everything dry.

airsmith282
01-03-2010, 02:03 PM
my shop is 8x12 and in the winter i heat 24/7 with a 100 watt ceramic forced air heater, its not costing me alot to use it like this and the shop even at -30 Celsue is staying about 25 Celsue gets pretty dame hot guess i did the insalaton job right, i cant aford to have to tools get cold takes to long oto warm up cold metal and its hard on the machines period my mill quill gets right sluging when it to cold so i chooses to keep my shop hot all the time and i have never had any isses this way..

Oldbrock
01-03-2010, 02:13 PM
220 v baseboard heaters work to keep my shop dry and warm enough (50) Don't know what difference it makes to my power bill. Don't have gas so all our heat and other power requirements are electric. The only time I have rust problems is if I'm stupid enough to open the muriatic acid inside the shop. Peter

MichaelP
01-03-2010, 03:03 PM
Warmer air will hold more moisture. I'd try a dehumidifier first. As I mentioned in the original post, dehumidifiers don't work when it's cold. So the most challenging time is not the hot moist seasons, but cold winter.

J Tiers
01-03-2010, 03:23 PM
So the most challenging time is not the hot moist seasons, but cold winter.

That should NOT be the case, unless there are significant moisture sources inside. Cold air warmed-up tends to DROP in relative humidity. Warm air carries more moisture, IF IT IS AVAILABLE, so the *relative* humidity drops when you warm up cold outside air that has very little to start with.

Usually the normal leakage of the building will exhaust enough air to take away your exhaled water. Most buildings have at least 0.25 air changes per hour, and many have 1 or even 2.

Ohio Mike
01-03-2010, 03:33 PM
If you're warming up the shop with a heater then its warm enough to use a dehumidifier. I have a small one plugged in all the time but I keep the garage at least 50 degrees Fahrenheit with 5000 watt electric heater.

MichaelP
01-03-2010, 03:36 PM
Yes, but this will be too late. The condensate will accumulate on the metal long before the dehumidifier will have a chance to remove moisture from the air.

The transitional period from the cold to warm environment is what kills. Only because the metal (esp., large chunks of it) doesn't get warm as quickly as the air when you start heating the shop.

MichaelP
01-03-2010, 03:43 PM
That should NOT be the case, unless there are significant moisture sources inside. Cold air warmed-up tends to DROP in relative humidity. Warm air carries more moisture, IF IT IS AVAILABLE, so the *relative* humidity drops when you warm up cold outside air that has very little to start with.

Theoretically, this is true. However, when you start heating the garage in the winter, the temperature differential between the air and the cold metal is so great that the metal always gets into the dew point range for the given air temperature. It's not the relative humidity per se that concerns us, but the dew point.

P.S. There are no moisture sources in my garage. Besides, it's not even insulated at this point, so the difference between the garage and outside air is not significant.

clutch
01-03-2010, 05:21 PM
my shop is 8x12 and in the winter i heat 24/7 with a 100 watt ceramic forced air heater, its not costing me alot to use it like this and the shop even at -30 Celsue is staying about 25 Celsue gets pretty dame hot guess i did the insalaton job right, i cant aford to have to tools get cold takes to long oto warm up cold metal and its hard on the machines period my mill quill gets right sluging when it to cold so i chooses to keep my shop hot all the time and i have never had any isses this way..

Wow, monster shop, mine's 8' x 10'. 1500 watt baseboard heater. 6309 Clausing Lathe (14x30") and and a Bridgeport. It is pretty snug inside. A bit like a glove.

It is in an insulated corner of my garage.

I'm near latitude 45N. I keep the shop at 52F/11C when I'm not inside and ramp it up to 66F/19C while working.

What machines do you have in yours?

Clutch

derekm
01-03-2010, 06:01 PM
Yes, but this will be too late. The condensate will accumulate on the metal long before the dehumidifier will have a chance to remove moisture from the air.

The transitional period from the cold to warm environment is what kills. Only because the metal (esp., large chunks of it) doesn't get warm as quickly as the air when you start heating the shop.

sorry to be pedantic - its the other way round. A cold shop has done any condensation its going to. Applying dry heat will not cause any more. This is because the machines are eihter at the dew point temperature or above it. Youneed to add more moisture to the warm air, for the condensation to occur. I.e. make the dew point above the temparature of the machines.
To make more moisture and increase the dew point, you can
1) breathe
2) run coolant systems.
This moisture in the warm air elevates the dew point above the temperature of the machines causing condensation on the machines

When you turn the heating off the further problems then occur as the temperature of everything falls below the dew point.

The trick is

run the heating on for a hour or two
then turn on the dehumidifier for an hour or two
then work,
after finishing working leave the heating on for an hour or two with the dehumidifier running,
then let the shop cool down for an hour our two with the dehumidifier running.
Then switch off the dehumidifier

MichaelP
01-03-2010, 07:00 PM
sorry to be pedantic - its the other way round. A cold shop has done any condensation its going to. Applying dry heat will not cause any more. This is because the machines are eihter at the dew point temperature or above it. You need to add more moisture to the warm air, for the condensation to occur. I.e. make the dew point above the temparature of the machines. I stand corrected. JTiers and you are, indeed, absolutely right. Thank you. It's time for me to return to the sixth grade, I guess. :)

Let's repeat to remember. For a given volume of air its dew point remains the same at any temperature (unless, pressure or moisture content were altered). What changes is the relative humidity number. Unlike RH, dew point is an "absolute" measure of moisture content.