Thoughts on a garage heater?

[Scouzer]

Right now my garage heater is a 220V 5000W unit the builder installed. It works well, I can make the garage +40 when it's -40 outside.

But I don't need that. Electricity is extremely expensive here. My power bills were over $350 a month last winter, the vast majority being the garage heater.

Part of the problem is that the current heater has temperature settings, but the minimum temperature it will accept is 10 degrees celsius. I don't need my garage that warm when it's -40 outside.

I would prefer 3-5 degrees.

My garage is better insulated than most: it's underground on one wall, against a neighbour on another, and about 50% underground on the other.

I've considered a 1500W oil heater but I'm just not sure if it would be powerful enough. I'm also not sure if I trust running a heater of that nature for months at a time--the big heater only turns on for a few minutes at a time.

Any ideas? Am I screwed as long as I use electricity? I really don't want to do all the work to switch to gas...

 

[lxskllr]

Why do you want a heater? If it's for the cars, maybe you can target the heat directly on the motor. Some kind of electric blanket maybe.

 

[Humpy]

Does the heater allow for an auxiliary thermostat that can be set lower? Or maybe the internal thermostat can be calibrated somehow?

 

[SlitheryDee]

You can't just replace the current 220v heater with a smaller one?

 

[Sho'Nuff]

Wood stove? Pellet stove?

 

[lxskllr]

What about ducting your house heat to it? Trickle it in, and it might keep things warm enough.

 

[weadjust]

You aren't supposed to run a duct from the house to the garage due to possible carbon monoxide poisoning and the fire hazard. It's against code however I have seen it done.

 

[dawks]

Most houses in SK and AB use natural gas. Glad you said you only need 3-5c.. I've seen people kept their garage at 21 all winter.
Yours doesn't have an external thermostat? Can't wire one in?

 

[LTC8K6]

You need a percentage timer for it. You can set it to run at a 50% duty cycle, for example.

 

[Murloc]

you mean it can do 40°C when outside it's -40°C?
That's crazy.
Anyway you should not use electricity if you want to spare money.

Putting a percentage timer on it doesn't sound that good if every time it gets turned on it will run at max power to reach 10°C again.

You may have to change the thermostat or the whole thing.

 

[Scouzer]

Why do you want a heater? If it's for the cars, maybe you can target the heat directly on the motor. Some kind of electric blanket maybe.

I have to have a heater for two reasons:

1) In my condo, the garage doubles as my basement. So I have not given any thought to what's down there in terms of whether it should freeze or not. I'd rather just not let it freeze.

2) There are water pipes down there since it's also my basement. They can't freeze.

Does the heater allow for an auxiliary thermostat that can be set lower? Or maybe the internal thermostat can be calibrated somehow?

Definitely no auxiliary thermostat--the unit can only be turned on with its own internal thermostat. As for intentionally buggering up the calibration in my favour... maybe.

What about ducting your house heat to it? Trickle it in, and it might keep things warm enough.

Very against code!!

 

[EagleKeeper]

Get a kerosene heater.

10K BTU and up

Use Google.

Example
$120 USD

• Portable 23,000-BTU kerosene heater for rooms up to 1000 square feet
• Automatic push-button ignition; 1.9-gallon fuel capacity provides 10 to 12 hours of heat
• Ideal for both everyday supplemental heating and emergency situations
• Fuel gauge; automatic safety shut-off; siphon pump and batteries included
• Measures 18-3/4 by 18-3/4 by 27 inches; 2-year limited warranty

Northern Tool - Good Selection to review

you will need to determine the square footage of the area to heat before making a final decision.

 

[LTC8K6]

you mean it can do 40°C when outside it's -40°C?
That's crazy.
Anyway you should not use electricity if you want to spare money.

Putting a percentage timer on it doesn't sound that good if every time it gets turned on it will run at max power to reach 10°C again.

You may have to change the thermostat or the whole thing.

A percentage timer should be perfect.

It wouldn't be on for an hour and off for an hour. It would be a faster cycle, such as on for 2 minutes, and off for 2 minutes.

Ideally, it would be wired so that it limits power to the heating elements themselves, rather than the whole heater.

 

[LTC8K6]

Come to think of it, it's common for those electric utility heaters to be adjustable for different KW levels. Maybe yours can be set to a lower power level?

Such as this one:

http://raceabilene.com/machine/docs/G73_Heater.pdf

 

[Scarpozzi]

Space heaters are ok as long as you don't store combustables in your garage.

One thing you could look into is some kind of solar heat exchanger: http://www.instructables.com/id/Solar-Heater/

If you look into solar, do research of evacuated tubes. An array of evacuated tubes can generate 400-500 degree temps on cloudy days....with a small amount of pressure, this can melt most pex tubing, so if you aren't storing the heated liquid in a tank, only use metal. You could buy an array of evacuated tubes and run copper pipe from the array into your garage to an old radiator using a small pump and a fan....it'd be a cheap way to heat because you'd only have to run electric to the pump and the fan. Both could be wired to another solar array if you wanted to go 100% solar.


I'm a few weeks away from pouring a slab in mine....I'm going to bury pex in the slab and do radiant floor heat with an electric mini-boiler next year when I save up the cash for it....unless I get talked into solar. It just doesn't get that cold here (typical low of 20 degrees for a month or so of the year), so solar may be overkill.

 

[K1052]

If you're going to be in the house for a long time I'd probably cough up the money to put in a gas fired boiler radiant heat system. Much more economical and controllable over the long term.

 

[mmntech]

Are the above ground walls insulated? Ours is and it doesn't get below freezing in the winter.

You could install a natural gas shop furnace or infrared heater provided it's well away of anything flammable. Like one of these bad boys. The same they use to heat hockey arenas.
http://www.sportsmansguide.ca/net/c...spx?a=710431&gclid=CP7n8bGUjLkCFZE7MgoduVEAZw

How big is the garage in square feet?

 

[Strk]

I'd say pellet stove. They put off a lot of heat and the venting requirements are minimal.

 

[NetWareHead]

Wood stove is probably what you want although you have to be there to load and ash it out. Not feasible if you are away frequently and desire an automatic solution like an electric heater.

Pellet stove is a better solution in this case. It feeds automatically and requires you only to feed a hopper once a week or so. You still need to ash it out every few days. Pellet does have the problem of fuel storage; they need to be kept dry or else the pellets disintegrate into a mush and are useless for heating. Burning pellet fuel is like burning wood and deposits creosote into the vent stack; requiring sweeping.

Coal is an option as well. Rice sized coal is the same size as pellet fuel and stoves are available that operate just like a pellet stove. You need to feed them once a week or so and ash out every few days. Coal is the better fuel compared to pellets. Twice as many BTUs than pellets, can be stored outside and even burned wet, wont disintegrate in moisture and won't attract insects. Coal also wont deposit tars and creosote in the chimney like wood does meaning the threat of a chimney fire is non-existent with coal. If you can buy coal in your area, compare it to pellet and see for yourself.

 

[natto fire]

Not sure if you own or are renting, or how involved you want to get, but a relatively easy solution is to wire the heater in series with contactors that are triggered by an external thermostat. This will only work if your heater automatically returns to it's previous state after losing power.

That would be a solution that would require zero maintenance when complete, but will not save as much money as one of the combustion heat options. Of the combustion heat options, I think it would depend on what you are storing in your basement/garage. Kerosene and wood can put off soot if there is not complete combustion, which requires careful, thorough maintenance.

 

[Midwayman]

Is the ceiling insulated? The door?

 

[Paperdoc]

Reworking the system to use a lower-wattage heating element is NOT going to change your problem. If you use a lower wattage, the thermostat will simply keep it turned on longer so the same amount of heat (watt-hours) is used. That is, as long as the smaller heater actually can keep up with the heat loss. If it's too small, it will run full time while the space temperature drops to some lower level.

Nor is a controller based on "% of time ON" going to do the job. That will fix how much energy is used for heating the space, but it will give NO control over the temperature. Unless OP monitors it and constantly re-adjusts the setting, the space temp will fluctuate according to the outside temps. So sometimes it will waste energy over-heating, and other times it will risk allowing pipes to freeze. Definitely not what OP needs.

Consider your liability, OP. If this space is in a condo structure and contains water lines, what is your legal position if those lines freeze? Would that impact other adjacent unit owners, or only yourself? Would a line rupture and water leakage cause damage? Where, and to whose property?

Consider also, with respect to line freezing, where is the COLDEST spot in this space? You say it cannot go below 10 degrees (I presume Celsius) at the thermostat, but it may be much colder near a wall. Is that where there is a water line or sewer line that could freeze if the thermostat-area temperature were just a few degrees cooler?

You most certainly ARE paying top dollar for the heat in this space - electricity is usually the most expensive energy source. I think the best suggestions are to ADD another low-cost heat source that runs in parallel with your existing electrical system. Something like an automated wood pellet system, or maybe a small oil furnace. Whatever heat this new system provides will produce a corresponding reduction in heat from expensive electricity. If either system fails, the other is still working as backup. The trick, though, is thermostat setting. You need the cheap new system to do ALL of the heating if possible, so its thermostat should be set HIGHER than the electric system. I guess that really means you'd need to find a way to lower the electric system's thermostat setting (as you have considered) - say, something like 5C, with the new cheaper-fuel system set at 7C.

The big question will become: are the likely savings on energy costs over (how many?) years going to offset the initial costs of buying and installing the new additional unit?

 

[vi edit]

Cut out part of the slab and repour with radiant heating powered by a gas water heater(edit: or wood pellet)?

 

[natto fire]

Reworking the system to use a lower-wattage heating element is NOT going to change your problem. If you use a lower wattage, the thermostat will simply keep it turned on longer so the same amount of heat (watt-hours) is used. That is, as long as the smaller heater actually can keep up with the heat loss. If it's too small, it will run full time while the space temperature drops to some lower level.

Consider your liability, OP. If this space is in a condo structure and contains water lines, what is your legal position if those lines freeze? Would that impact other adjacent unit owners, or only yourself? Would a line rupture and water leakage cause damage? Where, and to whose property?

I was going to mention this in my post as well. My solution posted above would avoid this for the electric, you could even use a thermostat that can check multiple sensors and doesn't trigger until a certain average is reached, or a certain temp on just one sensor. As far as the contactor, the ones I have seen are usually triggered by 110v AC, but there are definitely some that can be triggered by the more common (for thermostats) 24v DC.

I think the OP needs to reply as to whether he owns the property. I assumed so by the fact that he mentioned switching to gas, but also know what happens when you assume.

 

[LTC8K6]

Reworking the system to use a lower-wattage heating element is NOT going to change your problem. If you use a lower wattage, the thermostat will simply keep it turned on longer so the same amount of heat (watt-hours) is used. That is, as long as the smaller heater actually can keep up with the heat loss. If it's too small, it will run full time while the space temperature drops to some lower level.

Nor is a controller based on "% of time ON" going to do the job. That will fix how much energy is used for heating the space, but it will give NO control over the temperature. Unless OP monitors it and constantly re-adjusts the setting, the space temp will fluctuate according to the outside temps. So sometimes it will waste energy over-heating, and other times it will risk allowing pipes to freeze. Definitely not what OP needs.

Consider your liability, OP. If this space is in a condo structure and contains water lines, what is your legal position if those lines freeze? Would that impact other adjacent unit owners, or only yourself? Would a line rupture and water leakage cause damage? Where, and to whose property?

Consider also, with respect to line freezing, where is the COLDEST spot in this space? You say it cannot go below 10 degrees (I presume Celsius) at the thermostat, but it may be much colder near a wall. Is that where there is a water line or sewer line that could freeze if the thermostat-area temperature were just a few degrees cooler?

You most certainly ARE paying top dollar for the heat in this space - electricity is usually the most expensive energy source. I think the best suggestions are to ADD another low-cost heat source that runs in parallel with your existing electrical system. Something like an automated wood pellet system, or maybe a small oil furnace. Whatever heat this new system provides will produce a corresponding reduction in heat from expensive electricity. If either system fails, the other is still working as backup. The trick, though, is thermostat setting. You need the cheap new system to do ALL of the heating if possible, so its thermostat should be set HIGHER than the electric system. I guess that really means you'd need to find a way to lower the electric system's thermostat setting (as you have considered) - say, something like 5C, with the new cheaper-fuel system set at 7C.

The big question will become: are the likely savings on energy costs over (how many?) years going to offset the initial costs of buying and installing the new additional unit?

Well, he has way too big of a heater if it can keep the garage that much warmer than the outside, imo. He said

I can make the garage +40 when it's -40 outside.

So he can heat his garage to over 100F when it's -40F outside.

The installer probably just left it at max KW.