Shop Heater Question

[scott vroom]

I installed a Fahrenheat FUH724 7500 watt shop heater about 3 years ago to heat a 28 x 22 shop. I'm on the eastern slope of the Cascades at about 4,200 feet and winter temps are very cold. The heater takes well over an hour to begin warming the shop. Part of the problem is that the heater is off during the night and the walls/ceiling act like a heat sink when I fire up the heater in the morning....shop air space doesn't begin to get comfortable for a considerable amount of time. There's no natural gas where I live, only propane and electricity. I was wondering what others are using to heat their shops during the winter. I don't have floor space for a wood stove.

Thanks

[Jerome Stanek]

I have a propane torpedo heater that I run for about 15 minutes to get the temp up before the small propane wall unit takes over

[Kevin Jenness]

I used to heat only with wood and had the same issue- although my shop is pretty well insulated the temp would drop from the 60-65 I like to work at down to 50 or below on a cold night and would take an hour or so to get comfortable. I had a Fujitsu air to air heat pump installed that keeps the temperature at 60 overnight. These units are pretty efficient down to 10 degrees or so and are supposed to function as low as -15- they are becoming very popular around here. They also can act as an air conditioner in hot weather.

[Bill Dufour]

7500 watt is less then 25000 btus so it will take a good amount of time to heat it up. This is a little less then a small wall heater. Propane is cheaper then electric heating not sure about heat pump vs gas cost.
I would recommend a mini split or a package unit heat pump/ac let it run at night to stay above dew point or warmer. If the neighbor is close use a minisplit since a package unit will be twice a s loud and annoy the neighbors all day and night with the noise.
Bil lD

[John M. Smith]

I used to heat with wood. Got sick of cutting wood. Last year I installed a Modine ceiling mounted propane heater. Used about 300 digestible worth of propane last year. But I also used the woodburner on weekends. Sold the woodburner this spring. So far about 150 digestible spent on propane. Im guessing about 500 dollars total for the year. Keep the thermostat set at 55°. And turn it up to 68 when im ot the. 32 by 40 foot shop building.

[Bill Dufour]

Or just install an old electric stove and use the oven with the door open to gain about 3,000 watts. It will be useful for baking paint and powder coating.
Bil lD

[Lee Schierer]

Here are some calculators (https://www.calculator.net/btu-calculator.html?roomwidth=22&roomwidthunit=feet&roomlength=28&roomlengthunit=feet&ceilingheight=8&ceilingheightunit=feet&insulation=normal&temperature=1&temperatureunit=f&ctype=house&x=71&y=17#housebtu) that will help you determine how many BTU (watts) you need to warm up your shop.

[Tom Dixon]

When I built my 24' x 36' x 10' shop a couple years ago I installed a 75k BTU Modine Hot Dawg HDS (https://www.qcsupply.com/modine-hot-dawg-heater-model-hds.html) enclosed combustion heater. It uses outside air so fumes and sawdust aren't an issue and it doesn't add any moisture to the shop either. I used the Quick-Sling Flush Mount and Vertical Concentric Vent Kit. I also use a programmable thermostat to keep the shop around 60 degrees weekdays and bring it up to 65 automatically on weekends. It costs me an average of about $35 a month to run during winter in central TN. I'm running the natural gas version but there is also a propane version as John mentioned earlier. I couldn't be happier with it. I stay very comfortable so it was worth every penny it cost me. I could have probably gotten away with a smaller unit but the cost difference was not much between 65K and 75k.

[roger wiegand]

I use the same Hot Dawg enclosed combustion heater. I put an Ecobee thermostat on it and can turn the temperature up from my phone (from anywhere in the world!) while having my coffee so the shop is warm when I get out there. If you're on a regular schedule a simple timer thermostat would also work. That heater is oversized for my shop, so it takes less than 15 minuted to bring it from 45 to 65.

[Tony Latham]

I've got a Rinnai vented propane heater in my shop and really like it.

T

[Eric Danstrom]

I live at 5kft in a climate I would think is a little colder than yours. I heat my 12x22x11 shop with a single 1.5kW electric resistive heater and thermostat (DeLongi oil filled radiator). This winter I decided to leave the heater on 24/7. I keep the shop at 55* during the week and on weekends I crank it up to 60*. The heater is able to keep up even when it's 10* outside.

I did insulated all the walls with r19 insulation/vapor barrier and taped all seams and cracks before drywalling. I made a cheesy insulation blanket to cover the garage door that I use in the winter to seal it well. Cost is running about $0.70 per day ($20/month).

The last few years I heated with propane right before I used the shop. I used a single daisy burner and gas grill style tank. I consumed about $30 per month along with the fumes and cold tools. Constant electric heat is better and cheaper for me.

(BTW, in my area, per BTU, propane and electric resistive heat costs are within ~10% depending on propane market variability.)

What I'm trying to say is I think you have plenty of heat. Perhaps it makes sense to keep your shop at a minimum temp and raise it when you're going to be in there. It keeps the tools at a reasonable temp. Prevents freezing fingers and condensation/rust too. Good insulation is critical and as energy costs skyrocket due to government mandated changes insulation will be even more important.

Long term I'm plan on getting a mini-split, heats at 1/3 the cost of resistive and adds air conditioning.

[Donald Hofmann]

I live at 5kft in a climate I would think is a little colder than yours. I heat my 12x22x11 shop with a single 1.5kW electric resistive heater and thermostat (DeLongi oil filled radiator). This winter I decided to leave the heater on 24/7. I keep the shop at 55* during the week and on weekends I crank it up to 60*. The heater is able to keep up even when it's 10* outside.

I did insulated all the walls with r19 insulation/vapor barrier and taped all seams and cracks before drywalling. I made a cheesy insulation blanket to cover the garage door that I use in the winter to seal it well. Cost is running about $0.70 per day ($20/month).

The last few years I heated with propane right before I used the shop. I used a single daisy burner and gas grill style tank. I consumed about $30 per month along with the fumes and cold tools. Constant electric heat is better and cheaper for me.

(BTW, in my area, per BTU, propane and electric resistive heat costs are within ~10% depending on propane market variability.)

What I'm trying to say is I think you have plenty of heat. Perhaps it makes sense to keep your shop at a minimum temp and raise it when you're going to be in there. It keeps the tools at a reasonable temp. Prevents freezing fingers and condensation/rust too. Good insulation is critical and as energy costs skyrocket due to government mandated changes insulation will be even more important.

Long term I'm plan on getting a mini-split, heats at 1/3 the cost of resistive and adds air conditioning.

What are propane and electricity prices there currently? Thanks

[Eric Danstrom]

What are propane and electricity prices there currently? Thanks

The incremental cost of electricity here is right around $0.10/kWh (no hook up or meter charges averaged in). Propane is ~$18 for a 20gal refill after rebates.

[Jeff Monson]

Scott, how often are you in your shop?? If its every day I'd look into a hot dawg style propane furnace and keep it at a low temperature until you want to work. These style are pretty efficient and heat a space like yours very quickly (assuming its properly insulated). I use radiant floor heat in my new shop with a propane boiler.

[Donald Hofmann]

Thanks, I thought you were saying that bulk propane was more expensive than electricity. In southwest Colorado propane is about $2.10 gallon while electricity is around .13 so unless you have a mini split that is very efficient resistive heating is no where near as cheap as propane.

You can rent a 500 gallon propane tank for $50 year. You paid about $3.60 gallon to fill your small tank. It wouldn't take much propane to break even on renting a large tank and getting bulk prices.

[Jack Frederick]

Look at the Rinnai EX-22. You will be very comfortable with it. Not cheap, but you get what you are paying for. You can install it yourself in about two hours. It is direct vent and the vent is in the box. It is a "one box" install unless you need vent extensions for some reason. Modulating burner (8200-20,500 btu on LP) and modulating blower. The built-in programmable stat is simple and reliable. Cool to the touch and quiet. In your area, check with Ferguson Enterprises, Keller Supply or Western Outdoor Wholesale. I can answer any questions on it and will help you.
Your other option is a mini-split heat pump. For straight heat I prefer gas, but you will get cooling out of a mini-split as well as heat. It is a pro install on the mini-split.

[Eric Danstrom]

I'm paying ~$4 per gallon propane so that makes it about even. Using your price of $2.10 makes it about 60% cheaper than resistive electric heat. I guess the term "no where near" is somewhat subjective. Once a heat pump is used the electric heat cost drops by 3x (30% the cost of resistive) and propane costs are crushed by electric heat (1/2 the cost of propane).

Propane has 91,500 BTUs per gallon or 43570 BTU per 1$ when propane is $2.10 per gallon (21785 per $1 @ $4/gal)
Electricity has 3410 BTU per kWh or 26230 BTU per $1 when electricity cost is $0.13 per kWh (this cost drops by 3x with a heat pump)
Heat pump BTU per $1 is ~ 75000 BTU

My local electric rate is ~$0.10 per kWh incremental cost without any fixed costs such as meter and hook up.

[Eric Danstrom]

If OP already has the electric hooked up spending the money to change to propane and renting a tank seems like alot of expense when he could run a mini-split and lower his heating cost to 1/2 the cost of propane.

[Jack Frederick]

Wow, Eric! Being in CA I always think we are in the high end of ALL costs, but I just filled at $2.02/gallon. I would suggest going to all the neighbors and finding the size of their tanks, do they own their tank, annual usage and price/gal average/company. Form an association and get quotes from all of the local LP companies for the association. I am doing that here. No results yet my daughters neighborhood association filled at $1.65.

[Eric Danstrom]

I have a city lot, I'm not going to rent a 500gal tank when I was using ~8 gallons a month for 3 months of the year (probably against zoning too). Doesn't take much micro economics knowledge to figure than one out. I have natural gas heat, its a city thing, nobody has propane because NG is much cheaper than propane. Running the line to my garage and adding in a new furnace doesn't make sense compared to a mini split either. Mini split give me ac too, thats good in my climate.

If you want to claim vented propane is better for OP than using what he has or a mini split then make the case with numbers. Un-vented propane has fumes and you're forced to run in burst mode which I found wasn't that cheap compared to running electric 24/7.

By the time you get op swapped over to propane he could have dropped $1500 for a deluxe mini-split tha cost 1/2 the cost of propane at $2.00 per gallon. Adding the efficiency of your propane furnace into the equation make the numbers even better for electric heat pumps.

[Dylan Wall]

I’m leasing 30’x60’ w/ about 18’ ceiling (peak). Have 2(two) 110 gallon tanks that cost about $450 to fill @ 15-20% from empty and $550 when you run them dry lol. Has a 2 year old furnace, looks like one you would find in a house not sure the btu. Thermostat is ALL THE WAY DOWN TO THE LOWEST SETTING I CAN PUSH THE DIAL for a 10*c working temperature. Tanks last 3-5week during the winter and man alive does it ever hurt when we get a cold snap. Most Payed in a month was $750ish. One tank will last all fall and spring usually.

10*c might seem cold to be working in but all you have to do is bundle up. Seriously, put on wool socks, insulated jeans, insulated coveralls, hoodie & a torque. Layer up and once you start working, as y’all know you’ll warm up. Buy quality, fitting clothes. NO STRINGS OR LOOSE CLOTHING OR TATTERED CLOTHING EITHER. Be safe!

Working in winter/cold can be dangerous. Get your shop to a temperature YOUR comfortable to work in. It’s only money, spend it before it’s gone lol

[michael dilday]

I am heating an 18x22 shop in Virginia with a 17,300 BTU window heat pump. It works great and heats fast.

[Jim Andrew]

I am 68 and still heat my shop with wood. If you have no floor space, invest in a outside wood burner. A friend recently bought a new hot air outside wood burner at Menards. Looks like a nice heater, and he has a huge morton building to heat. And he is 72. I figure I need to get exercise to stay healthy, my back is a bit weak, so bought a wood splitter, and drag it along when I cut wood, and roll the pieces to the splitter, break them up before loading them in my truck. Makes it easier on the back to break the wood up into smaller pieces. I built a small lean to onto the back of the shop close to the wood burner, to keep the rain and show off my stack of dry wood.

[Eric Danstrom]

...Have 2(two) 110 gallon tanks that cost about $450 to fill @ 15-20% from empty and $550 when you run them dry lol....
You're paying CN$2.50/gallon which is 36,600BTU per CN$1 and with 80% efficiency is about 29,000BTU per CN$1.

Electric rates in GTA are set by time-of-day between CN$0.10 and CN$0.20. With resistive heating your BTU cost per CN$1.00 is between 17,000BTU per CN$1.00 and 34,000BTU per CN$1.00.

A heat pump will increase efficiency of electric resistive heating by 300%. That would drop your BTU per CN$1.00 to 1/3 the cost of electric resistive heat. That would make your costs between 51,000BTU per CN$1.00 and 102000BTU per CN$1.00.

Electric heat pump in GTA would drop your heating costs compared to $2.50/gallon propane by 1/2 to 1/4 depending on the time of day.

[Darcy Warner]

I know you said you don't have floor space, but a used pellet stove is cheap and they are not very big.

[Eric Danstrom]

I know you said you don't have floor space, but a used pellet stove is cheap and they are not very big.

At $0.12 per lb of pellets the BTU per $1.00 is ~57000 BTU per $1.00 if the stove's efficiency is 80%. That's 50% the cost of propane with an 80% efficient furnace. I didn't know pellets were than cheap. OP is still better off with a heat pump. Lower costs potential, no filling the furnace, no fire hazard (with added insurance cost) and, if he cares, lower CO footprint.

[Darcy Warner]

At $0.12 per lb of pellets the BTU per $1.00 is ~57000 BTU per $1.00 if the stove's efficiency is 80%. That's 50% the cost of propane with an 80% efficient furnace. I didn't know pellets were than cheap. OP is still better off with a heat pump. Lower costs potential, no filling the furnace, no fire hazard (with added insurance cost) and, if he cares, lower CO footprint.

Pellet stoves are sort of a seal combustion deal, as soon as the door opens, senses fault, it goes out. I can load 120 pounds in mine and not touch it for 3 days.

[Eric Danstrom]

Apparently pellet furnaces are closer to 70% efficient so that adds another 14% cost compared to the 80% I used. Bottom line is if you're paying $0.10 per kWh then heat pump is the cheapest by far. At $2.00 per gallon propane the break even cost for a heat pump is $0.32 per kWh. At $1.50 per gallon the break even cost for heat pump is $0.24 per kWh.

Edit: "break even" is when propane heat and electric heat pump heating cost are equal. At $2.00 per gallon and $0.10 per kWh, electric heat pump heat is 1/3 the cost. At $1.50 per gallon and $0.10 per kWh, electric heat pump heat is 2/5 the cost.