Garage heater - low temps

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I contend it is the same reason. :)

I'd even wager they would give the same answer for any geographic area outside the High Plains or Desert Southwest (and would be highly like to there as well because they probably have no experience in any other climate so would still use the CYA answer).

Reply to
dpb
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Another consideration is a safety factor. A building at 50 degrees will stay above freezing longer in a power failure than one at 32.1111 degrees. Not a big deal if comfort is the only consideration, but if keeping water from doing damage, you have to plan ahead a bit.

I maintain a large (poorly insulated) building that is used for storage, but cannot freeze. Keeping it at 45 is good for at least 30 hours.

Reply to
Edwin Pawlowski

Don't let my kids see this post! They'll want me to turn up the thermostat in the winter using the "we'll stay above freezing longer in a power failure" excuse.

Shut up kid and go get another sweater. ;-)

Reply to
DerbyDad03

This sort of thing is going to be very dependent on conditions. Not just environmental, but building structure and ventilation. As a simple example: our garage.

It's vapor-barriered (6 mil plastic) and insulated with decent attic ventilation. When we moved in, the floor was just gravel. Unheated. Approximately two days per year (usually in the fall), there was a moisture problem that caused bare metal (eg: my tools) to begin to rust. Visible condensation everywhere.

A few years later, we had a concrete floor put in with a layer of foam board under it. Moisture/rust problems _completely_ disappeared. There are now heaters in it, and I only turn them on when I'm going to be working in the garage for extended periods during the winter. When the heaters are off, the temperature in the garage can drop as low as -30C or lower during the winter. Zero moisture problems (except when the ceiling vapor barrier fatigued in a few places and fell through, and the attic got too warm - icicles and condensation at the ruptures.)

The cottage is similarly well insulated and vapor barriered (kraft insulation). We heated the cottage itself to 4-5C. At first there was a moisture issue _under_ the cottage - concrete block foundation, dirt floor, and we also kept the pump area warmer by enclosing the section with a double "curtain" of 6 mil plastic and a fan heater modified to operate at around 5C. But that was eliminated by power venting the crawl space outside of the "bagged" zone.

The only moisture deterioration problems were in the cottage ceiling due to "cathedral ceiling" (2x6 Cedar T&G, 1" foam, sheathing then shingle - no ventilation), no sunlight due to trees (roof stayed damp) and (eventually) carpenter ants. Everything was torn off but the T&G, "joists" were laid over the T&G, bat insulation with a 2" airgap under the sheathing. Moisture problems eliminated.

Anyone saying "don't go lower than 50F" or something like that will be doing a CYA because they don't know whether it really will cause a problem or not. Whether it causes a problem is determined by the building and weather conditions.

Reply to
Chris Lewis

Thanks

This one covers the range I need 40 to 99 degrees, the stores just dont sell 40 degree thermostats.

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Reply to
RickH

Thus my reason for adding the last line to my post:

In any case, the OP might want to do a little research and determine if "just above freezing" is the correct temperature for his location.

Reply to
DerbyDad03

This may meet the OP temperature specs, but it won't meet his other requirements. The specs at the site say: "For Use With Gas, 24V Electric Heat, Oil".

The OP is looking for a stand alone heater or a control for a standalone heater that can be set for low temps, not a thermostat for a furnace.

Reply to
DerbyDad03

I live in Canada where it would be usual to have this application. The garage that I want to heat to just above freezing is attached to the house, well insulated so a heater with a thermostat that can be set from about 0 degrees C to 10 degrees C or more would fit the bill. My question is - why do manufacturers not provide this option, and why can I not find ANY heater that gives the minimum and maximum temperature setting of the thermostat on the box?

Reply to
Gerry

There is something called a "frost cube" ? thermostat that you can control any heater with. I'll see if I cand find the information.

Reply to
clare

I have a ceiling mounted electric heater with fan. Not sure of the exact thermostat range as it's unmarked except for little dots and an off position. I keep at "just on" over the winter and it keeps my insulated shop at about 40 degrees. When I want to spend time out there working, I just pop in, turn it up a bit and within 15 minutes or less I can work in my shirtsleeves. At a rate of ~ $0.1035 per kWh the affect on my monthly electric bill is negligible.

If you can't find one looking through Grainger, et al, let me know and I'll pull the model number and make for you.

Alternatively, I suspect that it might not be all that difficult to find a line voltage thermostat that would operate in the range you want/need. Just wire it into the circuit and leave the thermostat on the heater set to your preferred "working temperature". Crank up the external line voltage stat when you want to work out there, turn it back down when you just want to keep it from freezing.

Reply to
Unquestionably Confused

It's called a thermocube thermostat. It turns on the heater at 35F and turns it off at 45F. It is available from Home Despot in the USA.

It is apparently a Canadian invention . Contact Christy Fabros Public Relations Specialist Nuheat Industries Ltd.

604.529.4391 snipped-for-privacy@nuheat.com for information on where to buy one close to you.
Reply to
clare

IF it was my problem, I would take the thermostat apart and adjust/bend something associated with the temperature sensor. Nothing to lose and maybe a lot to save/gain.

Reply to
hrhofmann

I am in Calgary. Has double attached garage insulated like main building. Small potable heater rated at 1500W max. keeps things from freezing.

Reply to
Tony Hwang

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Reply to
Chiily Willy

HD sells the plug-in thermocube. Before relying on one, I'd suggest reading online reviews. When I looked into them, I saw a lot of people saying they were unreliable, would work for a few months, then when it should go on, didn't and stuff froze.

I agree with the poster that you would think there would be more quality choices available for that kind of thing, but I couldn't find any other choices either when I was looking.

Reply to
trader_4

That's a nice find, except that it looks like it's a low voltage thermostat and an electric ceiling heater is almost certainly in need of AC.

Reply to
trader_4

However, I would think that any number of low-voltage-line voltage relay would work, no?

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Reply to
DerbyDad03

Gerry wrote: ...

think of it in terms of thermal mass, wind and insulation, a well insulated building might be able to maintain a near freezing temperature with a small heater, but if you set it too close to freezing and the temperature and wind changes then it can easily go below freezing and the small heater won't be able to keep up.

most electric heaters i've seen have an adjustable dial that has no specific heat number it's just dots.

the few i have here have Hi, Low and Fan settings.

i'd get a few of them, set them around the building and then adjust them so that one will work at the higher temperature and then set another at a bit lower so you have an extra cushion for when it gets really cold. the one lower unit will run more and then the other should only come on when the weather and wind get particularly cold.

songbird

Reply to
songbird

I've used those Thermocubes for livestock tank heaters, to prevent them from staying on when the air temperature rises above freezing. They are not very reliable. I wont buy them again.

They do sell thermostatically controlled fan switches, made for large barn fans, which are intended to turn on the fan when the barn temp rises above a set temp, such as 70deg. They are 120V switches. But I dont think they go down to freezing temps. I believe they make similar things for heating controls. Check out

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They sell a lot of that type of thing.

The OP could make a control if they are handy. Mount a relay in a suitable electrical box. The relay contacts must be at least 15A. (20A is better). Put a plug on cord and an outlet on this box. The plug goes to a wall outlet, the outlet feeds the heater. Then mount a 24V transformer on the box, and run wires to a plain thermostat (not programmable). The relay must have a 24V trigger coil, the wires from the thermostat feed that relay trigger coil.

It's hard to explain without a wiring diagram, but it's a simple circuit. A thermostat is really just a switch that is controlled by temperature. It's just switching the relay to the ON position when the temperature falls below a certain temp, such as 40deg. The relay contacts are 120V and they turn the heater on and off.

I built something similar once, but in my case the relay turned my furnace on and off, based on a sensor on a woodburner. When the woodburner got above a certain temp, the furnace was turned off. The reason for this was because both shared the same ductwork. If both the furnace and woodburner fans ran at the same time, the big blower in the furnace would overpower the small fan on the woodburner, and cause it to self destruct. This relay insured that both blowers did not run at the same time. Relays are very useful for lots of things.

Reply to
Paintedcow

Why not just use the device that is "made for the job" The ThermoCube is made to control a 1500 watt heater to prevent freezing. On at 35F, off at 45F. If you want to work in the shop, unplug the heater from the thermocube and plug it in directly, letting the built-in thermostat do it's job.

Reply to
clare

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