Electric Shop Heat

[CWink]

I have a stand alone 30x40x10 garage. Currently insulating with R13 in the walls and R30 in the ceiling. Looking for electric heating options and wondering if a 7500 watt heater would suffice? Wanting to stay electric as I plan to install solar panels on the garage in the future.

 

[txvwnut]

I think your gonna be a little light with that one for the size of your place. I want to say when I did the math for my shop which is 20x26 that is two levels and it came out to a little more than 7500 watts to heat it. But I also have propane heat to help bring the temp up and then the electric will maintain it after that.

 

[justinjoyal]

You must determine the exterior and interior design temperatures before you can size the heater.

What interior temperature do you want to maintain? Do you need quick recovery (for example if you have a large garage door thats going to be opened often.) ? What,s the average temperature in your area during the coldest months of the year ?

 

[Chilliwack Murray]

Electric heat is 100% efficient (without a fan) but it is still consumes a tremendous amount of electricity.

As long as you have enough wattage to keep up with losses, the amount you have has little effect on total (net) energy used. A 10kw heater will use twice the electricity in kWh for half the time compared to a 5kw heater to produce the same amount of heat.

You’re heating a shop so you could probably get away with less wattage than the electric heat calculators suggest since you don’t need to keep it at room temperature. Net energy (kWh) use will be the same.

You need to get past watts and think in terms of watt hours which would be the equivalent of gallons of fuel used.

I think you’ll find you’d be hard pressed to install enough solar electricity on a building to heat that same building with electricity. I’d be happy to be proven wrong but I’d also hate to see you shell out cash for something that won’t work in the end.

 

[RoadBeater]

I’ve got a similar building, with a 7500 watt heater that I have a cord to put into my welder outlet. Usually, I just put it in front of the car I’m working on. It does ok. It’s just got n a switch, so occasionally I’ll turn it off if I’m warm. Its not like I’m out there all day, usually just a couple of hours here and there. Not sure how it would do to try to heat the whole building. I have the same heater in my attached garage 25x28, it’s on a thermostat and heats that area fine.

 

[CWink]

You must determine the exterior and interior design temperatures before you can size the heater.

What interior temperature do you want to maintain? Do you need quick recovery (for example if you have a large garage door thats going to be opened often.) ? What,s the average temperature in your area during the coldest months of the year ?

I do have one large garage door. I am thinking I would only want to keep it around 45-50 most of the time and then up to 60-65 when I want to work in there, maybe once a week for 8-10 hours. I am around St. Louis and we typically have 4 months I would use the heater. Highs in the low 40s and lows in the 20s. We typically only have one or two weeks a year where it gets around 0 and the highs don’t get above freezing.

 

[Dagny]

poor house

 

[lakeroadster]

You must determine the exterior and interior design temperatures before you can size the heater.

And what is in the space? Freezing cold vehicles have a lot of mass that need to be heated. Huge difference from a home.

If your are bringing cold vehicles into the space... vs doing wood working projects.. that has a big impact on what your heat source BTU's are required.

 

[CWink]

Is the general consensus that a hanging propane heater would be the best option? It is an option for me I just wasn’t to keen on cutting a hole in my roof for the vent and the horizontal vents seem so expensive.

 

[oledude1952]

1200 sq. ft. garage with cold vehicles going and out while using all electric ? Whew $$$$

Yep, propane is a really good alternative.

 

[850xpeps]

What about a forced air furnace from a house? You can pick them up for $100 used and just remove a few banks of elements to get to say 10kw. The air movement of that heater will do wonders for keeping it warm. This would be my choice. But I don’t have access to natural gas either. Not sure which I would choose if I did. Gas is cheap but like you said I wouldn’t have to cut any holes and I can install myself if electric.

My last 26x26 had a hanging furnace that I had cut down to 5kw. With temps of -25 Celsius it had no issues warming the garage.

 

[Slednut]

I would wire for a 5000 watt heater, I have one in my 26x56x9 but it's attached and a lot easier to heat.

Installing a curtain to keep the heat (or cooling) where you are working can save on energy costs.

 

[xyster101]

Think about this: Power plants typically burn fossil fuels to make steam, to turn a turbine, to make electricity. Then that gets transferred to your house where you turn it into heat. Just skip all that and you burn the fossil fuels to heat.

A 7500 watt heater will cost you around 70 cents an hour to run if you pay 10 cents a kilowatt. No idea how often it will run in a shop, but if it ran 3 hours a day X 30 days = $70 a month or more.

 

[nsula_country]

Installed a 20Kw furnace in our 40x60x17 building with modest insulation. Works well. Finishing up on heat pump and duct work.

Check build in signature for details.

CT

 

[Skiff Builder]

I run a 7500W in a shop half the size of yours with 15' open ceiling Wink, same insulation values. Only on when I'm in there working.Heats me up from 40 to 65 in about 45 min.

In my area , elec is same cost per btu as residential bulk propane. Unit cost was way less and install was very simple. What are those hanging propane units, low to mid 80 % efficient? Our propane suppliers are shady too-easy choice for my shop.
Propane is about 91.000 btu/gal
7500W is about 25,591 btu

 

[yeldogt]

I run a 7500W in a shop half the size of yours with 15' open ceiling Wink, same insulation values. Only on when I'm in there working.Heats me up from 40 to 65 in about 45 min.

In my area , elec is same cost per btu as residential bulk propane. Unit cost was way less and install was very simple. What are those hanging propane units, low to mid 80 % efficient? Our propane suppliers are shady too-easy choice for my shop.
Propane is about 91.000 btu/gal
7500W is about 25,591 btu

I pay PSE&G almost .20 KW for my SJ office ... That's $5.86 per 100k BTU's ... even propane at $3 @80 is only $4.00

 

[yeldogt]

I have a stand alone 30x40x10 garage. Currently insulating with R13 in the walls and R30 in the ceiling. Looking for electric heating options and wondering if a 7500 watt heater would suffice? Wanting to stay electric as I plan to install solar panels on the garage in the future.

Just do simple heat load calculation with one of the online calculators -- that way you can see?

 

[HoosierBuddy]

I pay PSE&G almost .20 KW for my SJ office ... That's $5.86 per 100k BTU's ... even propane at $3 @80 is only $4.00

I'm paying about $0.70 per 100,000 for NG. That's the employee rate.

But...the employee rate is the same rate everyone pays...so I don't feel all that special.

Phil

 

[yeldogt]

running electric heat w/ solar requires a large system.


typically a small house using 1000k a month (total) -- needs 30 panels. maxing at 7500kw Peak. Not continuous. We were around 15k for that + batteries and that's only 1/2 the load I needed.

 

[HoosierBuddy]

running electric heat w/ solar requires a large system.


typically a small house using 1000k a month (total) -- needs 30 panels. maxing at 7500kw Peak. Not continuous. We were around 15k for that + batteries and that's only 1/2 the load I needed.

To make solar really work out you need to start with an efficient "life style" to begin with. That cuts down the size of the system drastically, and allows for payback.

So, you'd want to be using a heat pump solution NOT an electric resistance solution. But, before you sized that heat pump, you'd want to minimize the size required by having a modestly sized structure to heat and cool with lots of insulation, no air leaks, LED lights, very efficient appliances, etc.

You'd also want to limit your energy use for wasteful things like heating garages.

The concept of needing to heat your garage (especially 24 X 7) is a pretty new first-world issue.

And finally, even if you had the money for a decent sized solar system, you'd want to start by hooking it up to your house, not your garage. You need it hooked up where you have more load so it will pay for itself over time. Hooking up solar panels just so you could run a resistance heater 4 months a year (when the sun shines in the winter...which is not nearly as much as it does in the summer) would never make any sense if you put pencil to paper.

Phil

 

[yeldogt]

I'm paying about $0.70 per 100,000 for NG. That's the employee rate.

But...the employee rate is the same rate everyone pays...so I don't feel all that special.

Phil

NG gas is cheap everywhere ..... it's electric and propane that gets $$

 

[cabranch47]

I have a 30 X 32 insulated shop. Found a central air unit on the roadside, a/c coils were bad but heater was good. Built a plenum for it to distribute air in different directions. Cost practically nothing and works great.

 

[nsula_country]

I have a 30 X 32 insulated shop. Found a central air unit on the roadside, a/c coils were bad but heater was good. Built a plenum for it to distribute air in different directions. Cost practically nothing and works great.

I was going to go this route too... Must be a Louisiana thing! Until I decided add cooling capability, then went heat pump.

Used electric and gas furnaces are abundant IF you have connections to obtain cherry picked units from HVAC change outs (hint, a friend that is a HVAC guy). I scrapped out 3 functional NG furnaces last year from changeouts. Because I did not have NG or LPG at the shop.

CT

 

[Skiff Builder]

I'm paying about $0.70 per 100,000 for NG. That's the employee rate.

But...the employee rate is the same rate everyone pays...so I don't feel all that special.

Phil

I pay PSE&G almost .20 KW for my SJ office ... That's $5.86 per 100k BTU's ... even propane at $3 @80 is only $4.00

Really shows the disparity of energy costs, even in different regions / varying suppliers of the same state. After determining your needs you really have to compare fuels at your local rate along with expected usage,install cost, your occupancy time in that shop location.

 

[Brand X]

Think about this: Power plants typically burn fossil fuels to make steam, to turn a turbine, to make electricity. Then that gets transferred to your house where you turn it into heat. Just skip all that and you burn the fossil fuels to heat.

Solar, and Hydro power with about zero fossil fuels to supply our coop..(.0741 cost winter rates) Plug in/propane/pellet stove in my shop.. I use a 26 year old Austroflamm Pellet stove about 95% of the time.. Best for me, and nobody can tell you what is best for you..

I say try your heater, and then you will know more about what works best for you.. Propane is about about $1.49 right now, and would rather have wood type heat any day.. So I do. Never asked what is best, because not a one size fits all type of thing.

Some people do not have a pipe-line for NG, so that might not be a option al all.

 

[cj7jeep81]

I think you'd be better off putting in a several 5,000 watt heaters. I am heating a 16x39x9 machine room at the back of my shop with electric with similar insulation. I currently have one 5,000 watt heater in there, and it heats the one end pretty well, but not the other. Plan is to put a second 5,000 watt heater diagonally from the first, and that should work out fine (they only had one in stock when I bought it). The fans really don't blow that hard, and it just won't reach. Maybe putting one in each corner would work better.

Was originally going to use propane (no natural gas at my house), but operating costs were very similar, and propane heaters are much more expensive to buy and install (venting gets expensive in a hurry). Plus I'd have to deal with getting my 100lb tanks filled occasionally, which is a hassle.

 

[TractorJeff]

Really shows the disparity of energy costs, even in different regions / varying suppliers of the same state. After determining your needs you really have to compare fuels at your local rate along with expected usage,install cost, your occupancy time in that shop location.

Wife and I were looking at the Gas/Electric bill the other night.
Natural Gas Base price per Therm but then you need to add in Distribution price per Therm!
It comes out over 70 cents!
BTW
Propane is $2.49 a gallon right now

 

[HoosierBuddy]

Wife and I were looking at the Gas/Electric bill the other night.
Natural Gas Base price per Therm but then you need to add in Distribution price per Therm!
It comes out over 70 cents!
BTW
Propane is $2.49 a gallon right now

So Natural Gas at 70 cents per therm converts to a KWH cost of $0.024/KWH

NG at 70 cents per therm converts to an equivalent price of $0.665/gallon - just as a way to compare it to propane.

For the conversion above I used 29.307 KWH in 100,000 BTUs which is absolutely correct.

I used 95,000 BTU's in a gallon of LPG...which is an estimate LPG heating value actually varies based on the actual composition of the supply...but 95,000 should be pretty close.

 

[Skiff Builder]

This takes care of all the conversions.
Here is an easy way to calculate your costs per BTU of different fuels.
Go to the link below and plug in YOUR real cost for the various fuels.

http://www.amsenergy.com/fuel-cost-calculator/


Example of calculator

Guess I'm putting the old potbelly in the shop and ordering coal!

 

[nsula_country]

This takes care of all the conversions.
Here is an easy way to calculate your costs per BTU of different fuels.
Go to the link below and plug in YOUR real cost for the various fuels.

http://www.amsenergy.com/fuel-cost-calculator/


Example of calculator

Guess I'm putting the old potbelly in the shop and ordering coal!

Interesting... In your locale, Electric Resistive is cheaper than Propane and Heat Pump slightly higher than Natural Gas...

On GJ, anytime electric heat gets mentioned everyone talks about how expensive it is vs fossil fuels. Wood was almost as much as Natural Gas with A LOT more work involved!

Thank you for the interesting read.

CT

 

[BigWarehouse]

Planning on building a very large shop in the near future, but I'm all about being comfortable. First question I asked myself is how much will it cost to heat/cool this place, and of course, the answer is always "a bunch".

Instead I purchased several acres of forest. (tree farm) If my calculations are anywhere near accurate I have a lifetime supply of free heat, just gotta cut it down. If I only paid $500/year on other fuels I still come out way ahead vs what I paid for the trees. And when I get too old to cut firewood I can just sell the land for more than I paid! I also have a lot of really nice old hardwoods I might try to mill myself in the future.

Every area is different of course, but you might be surprised how cheap timber land can be per acre. I sure was.

 

[nsula_country]

Planning on building a very large shop in the near future, but I'm all about being comfortable. First question I asked myself is how much will it cost to heat/cool this place, and of course, the answer is always "a bunch".

Instead I purchased several acres of forest. (tree farm) If my calculations are anywhere near accurate I have a lifetime supply of free heat, just gotta cut it down. If I only paid $500/year on other fuels I still come out way ahead vs what I paid for the trees. And when I get too old to cut firewood I can just sell the land for more than I paid! I also have a lot of really nice old hardwoods I might try to mill myself in the future.

Every area is different of course, but you might be surprised how cheap timber land can be per acre. I sure was.

I'll pay $200 a cord if I was burning wood. We have 50 acres, about 10+ acres are small to mature hardwood only. Also have about 400 acres of family land with hardwood that would take a 36" bar to cut them down.

I grew up splitting wood. Grandparents had a Yukon multifuel forced air furnace. Heated a 2600~ sq house, 2 stories, little insulation. I spilt a f**kton of wood for them growing up. F**k that! Many a cord a year. Still have some in barn. +10 year seasoned. Burn in fireplace for ambiance.

To each their own. Thats why there are many fuels and options to create energy.

Let the electrons work! Only gas is in the lawnmower.

CT

 

[BigWarehouse]

Don't get me wrong, cutting firewood is work, but it's also exercise and a modern chainsaw and log splitter are ridiculously easy to use compared to anything even 20 years ago. I refuse to split anything by hand. And I think most of my fuel needs will be covered by trees that fell on their own, so little risk in chopping them up.

I'm even looking into hot water "fired" air conditioning, which is not cheap, but will run on firewood!

 

[ford33]

Put in a few ceiling fans and use them. The hot air will rise to the ceiling and you will have a noticeable difference in temperature. Think cold at floor and very hot at the ceiling.

Run the fans and you will even out the air temperature and be more comfortable and reduce the need to run the heater.

I have a small 5k watt heater in my 2 car attached garage with 10 foot ceilings. That little heater with a ceiling fan kept my garage at 67F when it was -27F outside last week.

 

[nsula_country]

Don't get me wrong, cutting firewood is work, but it's also exercise and a modern chainsaw and log splitter are ridiculously easy to use compared to anything even 20 years ago. I refuse to split anything by hand. And I think most of my fuel needs will be covered by trees that fell on their own, so little risk in chopping them up.

I'm even looking into hot water "fired" air conditioning, which is not cheap, but will run on firewood!

30 years ago we had nice saws and hydraulic splitters, big splitters. We mostly cut up deadfall too... Still A LOT OF WORK. Unless your broke or retired and bored (Grandfather, furnace bought in 1978 from MN, shipped to Louisiana), wood isn't an option. Unless you are some liberal energy conservative, which even then is concerned about CO2 caused by burning of fossil fuels.

Not putting you down. Many use wood. I grew up on wood. We were poor. But now, as long as I can afford it... If it can be piped or wired, I'll pay for it! Time comes I cannot, I'll cut trees with an ax if need be.

Corn stove may be an option in shop. Corn is cheap. Can buy in bulk by pickup truck bed load at harvest. 8' box is about 3000 lb for $200 if you know a guy...

CT

 

[shaggyant]

No one ever mentions it but generally coal is the cheapest heat if it’s easily available in your area. Skiffbuilder’s chart above shows this too. Coal is the reason the the industrial revolution was possible.

If I could reliably get coal where I am on the Wast coast I’d have a coal stoker stove in my house and shop.

 

[nsula_country]

No one ever mentions it but generally coal is the cheapest heat if it’s easily available in your area. Skiffbuilder’s chart above shows this too. Coal is the reason the the industrial revolution was possible.

Coal power plants own the coal mines. And buy from contract mines... Not their own pits.

If I could reliably get coal where I am on the Wast coast I’d have a coal stoker stove in my house and shop.

There are 2 coal mines within 60 miles of me... Would trucking coal in vs electric and HP be cost efficient? No idea... Coal goes to Power Plants, to make electricity.

CT

 

[shaggyant]

There are 2 coal mines within 60 miles of me... Would trucking coal in vs electric and HP be cost efficient? No idea... Coal goes to Power Plants, to make electricity.

CT

Coal is cheaper than anything else unless you have access to free firewood. Is there a coal delivery service near you? A company should deliver it just like propane or fuel oil.

 

[Roundhouse]

I have a wood heater in my house

I have never paid money for wood
And usually get oak delivered for free

When I see a tree being taken down near me I just stop and ask what they are doing with the wood

A lot of times they will bring it to my house and dump it

 

[Crazyjake8493]

Another thing to consider would be the payback-time for one type of heat over another. I have an attached garage currently heated with a convection propane heater, and I've been looking to go with a hanging ceiling heater. Though natural gas would be the preferred and less expensive option to run, it would be far more expensive to install.

For me, an electric heater would be the cost of the heater, plus a 2-pole breaker and 12ft of wire and conduit which I already have. The cost of NG would be the heater, 60ft of poly underground pipe, 2 service risers, 50ft black pipe for the garage and house, possibly upsizing the existing gas pipe in the house, plus the time spent digging the trench and running pipe. For the amount I heat my garage, it would take me 9 years to break even on the cost, and only then would the natural gas start to save me money. I'll probably end up putting in an electric heater before next winter to save the weekly trips to the gas station for kerosene.