Heating Garage w/ Dryer

[nadogail]

Don’t forget that you could buy the off road diesel fuel (dyed red) for a lot less per gallon since it avoids lots of tax. Here in CA you’d save about a dollar a gallon.

Even cheaper fuel would be waste oil.

Check out Waste Oil Burners

 

[Crazyjake8493]

With 240V available and an aversion to other fuel sources, I would just hook up a hanging electric heater. I've been using a 7500 watt heater to heat my 20x30 garage, and have no regrets. A clothes dryer sounds like a terrible idea for multiple reasons.

 

[racecougar]

A properly working propane heater doesn’t produce carbon monoxide. It does consume oxygen and produces roughly the same amount of water as the propane it consumes. Most likely the dryer will put less moisture into the shop than the propane heater per BTU produced.

For the curious, here is the reaction for the properly adjusted combustion of propane:

C3H8(propane) + 5 O2 → 3 CO2 + 4 H2O + Heat

No CO.

If something is wrong, in this case 5%less oxygen consumed in the combustion, you will get some CO:

2 C3H8 + 9 O2 → 4 CO2 + 2 CO + 8 H2O + Heat

This is why the CO detector and low oxygen shutoff are important, along with regular cleaning and maintenance of the heater.

Thanks! I learned something today.

 

[JRC3]

What I’m hearing is that OP actually is interested in saving heat from dryers that he sees going to waste. He knows he can heat his garage a lot of other ways. I think that a lot of the heat is staying inside anyway, heating the machine and the clothes. But I’d say, sure, put in a used one. Just vent it outside. Dryers aren’t made to push the exhaust through water. Might have to run longer, IDK. Machine probably has something so if heat builds up it doesn’t melt all your wires or something. I wouldn’t leave it unattended with the bucket-of-water thing. But, yeah, seriously, let us know how it turns out.

Just like an open fireplace, that is very inefficient because of the venting. Dyers move about 100cfm through the vent, pulling 100cfm out of the space would exhaust way more heat than the dryer would radiate.

And guess what happens when you vent air from the inside to the outside? It creates negative pressure and pulls outside air back into the space trough cracks and doors. Same applies to any non-concentric or non-two pipe gas venting.

 

[MileHighRover]

Just like an open fireplace, that is very inefficient because of the venting. Dyers move about 100cfm through the vent, pulling 100cfm out of the space would exhaust way more heat than the dryer would radiate.

And guess what happens when you vent air from the inside to the outside? It creates negative pressure and pulls outside air back into the space trough cracks and doors. Same applies to any non-concentric or non-two pipe gas venting.

I don't think you understand what the OP is wanting to do. The dryer would be vented to the interior of the garage, not the exterior.

 

[JRC3]

I don't think you understand what the OP is wanting to do. The dryer would be vented to the interior of the garage, not the exterior.

I understand completely what the OP is considering, I wasn't replying to what the he wants to do. Pretty sure when Joemctag says, "just vent it outside" and a few other things he means the dryer will radiate heat thinking it would be sitting in the garage. IDK.

 

[tinmanwpk]

If you decide to go the dryer route just get a pair of pantyhose (somewhere - we don't need to know). Tape the pantyhose to the dryer duct to use as a filter. Don't use the water in the pail, adds too much moisture. I used the pantyhose way back when to augment my basement heat in the wintertime in Ohio. Works great.

 

[laser3kw]

I burn a propane construction heater in my 30 x 40. I was worried about CO so I got a CO detector. Last Saturday, my garage started out at 22° and I burned my heater On "high" - 80k setting for five hours and brought the temp up to 57°. I checked the CO detector and the display never moved off "0".
I use 30# tanks and normally, on the low setting, 30k, I can get 20 hours (about 5 average days) of burn time per tank. I go thru 3 or 4 tanks per season. I have one on the heater and a full spare.
If I start my snow blower and run it for a few minutes, the CO detector definitely goes up!

Same experience here. I run a tank top propane heater in my 30'x60'x12' shop to get it up to temp, then maintain it with an electric 5kW unit. My CO detector never registers a reading with the propane heater, but if you fire up a car, even with the overhead doors open, it shows a CO level almost immediately.

A properly working propane heater doesn’t produce carbon monoxide. It does consume oxygen and produces roughly the same amount of water as the propane it consumes. Most likely the dryer will put less moisture into the shop than the propane heater per BTU produced.

For the curious, here is the reaction for the properly adjusted combustion of propane:

C3H8(propane) + 5 O2 → 3 CO2 + 4 H2O + Heat

No CO.

If something is wrong, in this case 5%less oxygen consumed in the combustion, you will get some CO:

2 C3H8 + 9 O2 → 4 CO2 + 2 CO + 8 H2O + Heat

This is why the CO detector and low oxygen shutoff are important, along with regular cleaning and maintenance of the heater.

the GJ brain trust lead me to get the CO detector and I am reassured (for the last 7 years) that my propane heater is not compromising my health.
If you have to burn propane, get a good CO detector with a readout

 

[Metal-Marc]

Thanks! I learned something today.

Yes. Today I learned that if you burn propane, you produce water. Thanks Captain.

 

[charbar]

Not sure if Ill add anything of value but here goes...

About 6ish years ago my parents built a new house with an attached 2 car garage. The clothes washer and dryer are in the house, on the wall that divides the garage and utility room. The carpenter vented the dryer right into the garage, just as you are thinking. While Im not sure that I totally agree with it, it seems to be working ok. At least right now... Dad keeps guns and a few other 'rust prone' items in there that I have not seen any negative affects on yet.

I swear to God that dryer runs constantly. The garage is insulated pretty well. You can definitely tell its high humidity though. While it does keep the garage somewhat warm, its definitely not enough to use as an actual heat source. Especially if you are only going to use it "once in awhile".

In short....with short time use or "every once in awhile" its probably ok. Would I do it? No, not worth it. As said, there are many other forms of heat that would be MUCH better and easier to use.

On the plus side, it does keep the garage smelling nice and fresh

 

[mike93lx]

If you decide to go the dryer route just get a pair of pantyhose (somewhere - we don't need to know). Tape the pantyhose to the dryer duct to use as a filter. Don't use the water in the pail, adds too much moisture. I used the pantyhose way back when to augment my basement heat in the wintertime in Ohio. Works great.

TIL ***** hose dehumidifiers the air

 

[exranger06]

Several comments that using an electric space heater is more efficient than using a clothes dryer. What difference would it make? Electricity is used to heat a coil of wire in both instances. How can one be more efficient than the other? Asking because I don't know.

Glen

It's not really that they're more efficient, it's just that you don't have to deal with the humidity and lint that a dryer produces when drying clothes. If the plan is to run the dryer without any clothes, then he might as well use an electric heater that will take up way less space and is actually designed for that job.

What WOULD be more efficient is using a heat pump. It still runs on electricity, but it doesn't convert tons of electricity into heat. The electricity is just used to run the pump, which takes heat that's floating around outside, and pumps it into the garage. Plus, he could use it as an air conditioner in the summer.

 

[glentre]

It's not really that they're more efficient, it's just that you don't have to deal with the humidity and lint that a dryer produces when drying clothes. If the plan is to run the dryer without any clothes, then he might as well use an electric heater that will take up way less space and is actually designed for that job.

What WOULD be more efficient is using a heat pump. It still runs on electricity, but it doesn't convert tons of electricity into heat. The electricity is just used to run the pump, which takes heat that's floating around outside, and pumps it into the garage. Plus, he could use it as an air conditioner in the summer.

Yes, I was referring to the clothes dryer running without clothes in it and it should be just as efficient cost wise as a regular electric heater. Can't see why not. Kind of big and in the way though, and not enough to heat a garage of his size.

BTW, I have a wall mounted Bard heat pump to provide heat/cooling for my garage. These are the type seen on construction trailers and temp school modules. Takes no inside space and works very well.

Glen

 

[Bert_]

I vent my dryer into the basement. It adds a little heat, I don't have problems with humidity but I don't do that much laundry and really only use it in the winter.

I just have a tube sock over the exhaust. Doesn't look like the house has ever had a hole to vent it outside.

Some people run a humidifier during the winter because the air is dry.

 

[u2slow]

Several comments that using an electric space heater is more efficient than using a clothes dryer. What difference would it make? Electricity is used to heat a coil of wire in both instances. How can one be more efficient than the other? Asking because I don't know.

The dryer has a bigger motor to spin.

A baseboard heater is even more efficient than a box heater - no moving parts.

 

[SALIV8]

If you don’t want to drop cash on a minisplit, a cadet com pak twin works awesome in my basement. I’d stay away from the electric baseboard heaters.

 

[Bert_]

The dryer has a bigger motor to spin.

A baseboard heater is even more efficient than a box heater - no moving parts.

You might think that but guess what happens to any inefficiency in that motor? It creates heat. Which is exactly what we're trying to do. So in this case it isn't wasted energy. All electric resistance heat is always 100% efficient no matter what.

 

[Fasthotrod]

Yes. Today I learned that if you burn propane, you produce water. Thanks Captain.

The same holds true for any hydrocarbon:

Natural Gas (CH4)

Propane (C3H8)

Gasoline (varies from C4 to C12 with respective hydrogen atoms)

Kerosene (varies from C6 to C20, but typically C9 - C16 with respective hydrogen atoms)

Diesel Fuel (varies from C10 - C20 with respective hydrogen atoms)

More info here: https://energyeducation.ca/encyclopedia/Hydrocarbon_combustion

This was one of the neat things about taking thermodynamics in college... being a motor head and understanding how an engine worked on a mechanical level was pretty cool, but then learning about the chemical process, how fuel actually burns, how different types of fuel burn, the differences between a diesel and otto cycle... it kinda pulled it all together.

Mark

 

[lml999]

But have always thought about a heat recovery system for our dryer in the winter. There's videos on how to make one. Basically just capture wasted heat energy into the garage. Same idea. Some sort of coiled exhaust duct with a fan. It doesn't get too cold here, but if I lived in a colder climate it would make sense for sure.

I bought a commercial version of that a while back...essentially a box that installs inline to the dryer duct, with a radiator style air to air interchange.

You don't get enough temperature transfer with this device to make the effort worthwhile.

If you look at an HRV or ERV system, they use a *lot* of surface area (many fine radiator elements) to provide the heat capture/transfer.

Anything short of that is just a waste of time and space.

 

[MileHighRover]

Pretty flippin' awesome natural gas dryer turned into a shop heater.

 

[Kev442]

As a natural gas dryer is only 80-90% efficient, I am having an issue with this video. But I've never been a fan of salamanders in the garage, no matter what they are burning.

As to the OP's original idea, the biggest issue is that you will not see a 20 degree temp increase drying one load of clothes as they are only 20k btu or so. It would take at least three, and at that point moisture in the air would be noticeable.
How do I know this? Because I have been doing it in my basement for 25+ years to counteract the dryness from the woodburner.

 

[Bluedodge]

Lots of naysayers here.

Go ahead and do it. Post of pictures after four months.