Shop heaters. One big or 3 small?

[squonk 41,067]

200A minimum if you're gonna run any kind of electric heat or big compressor. Resistance heaters really take the juice and inrush current on a compressor  or a welder being used when the heat is on will dim the lights pretty good

[ebinmaine 67,418]

13 minutes ago, squonk said:

200A minimum

 

The new style exterior breakers were on infinite backorder when we set up the power a year or so ago.  

At the time it didn't matter because we were intending to use wood heat. 

THAT got shot down by the State Fire Marshall if in the workspace and insurance company even if enclosed. 

 

As far as combining power draws - we're not in the habit of doing so and never had been so 100 amp works ok.  

 

We'll consult with the Electrician and State codes to see what their requirements are.  

 

 

[squonk 41,067]

100 amps worked before but if you add electric heaters the size you need that all goes out the window. You could have put in the wire and a 200Amp panel and just run minimum breakers for lights until the breakers you needed became available. I upsize everything. If it calls for # 6 wire I go # 4. If 150A is enough I go 200. Things always change. Doesn't hurt to have the capacity. 

 

Why external breakers and why not propane? 

[ebinmaine 67,418]

13 minutes ago, squonk said:

Why external breakers and why not propane? 

 

The external breaker is actually the meter mount. 

We couldn't get a 200 amp version.  

 

Propane here is not an option without spending several to 10's of  thousands of dollars.  

 

We can't have the tank(s) set anywhere around the building so it would have to be remote.  

 

We'd have to have a cement pad installed a distance from the building.  

The pad would need to be dug down and fill installed. 

Then a 4+ ft deep ditch put in for whatever distance that happened to work out. 

Then buying the unit. 

Then paying a professional installer. 

We were quoted anywhere from $8K to $15K or higher.  

Then we still have to buy the fuel. Also not cheap around here.  

It actually costs less to use a comparable BTU electric heater than propane.  

 

It IS possible but NOT practical.  

 

[wallfish 16,994]

Waste oil heater?

Diesel ? You could probably mix the waste oil in with the diesel like you can with those chinese cab heaters

https://www.amazon.com/Sunfire-Indoor-Outdoor-Commercial-Radiant/dp/B0BCMRPCDL/ref=asc_df_B0BCMRPCDL/?tag=hyprod-20&linkCode=df0&hvadid=598236124773&hvpos=&hvnetw=g&hvrand=14315066117320629762&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1018158&hvtargid=pla-1861718709258&psc=1&mcid=08c5e6f3b86d3e0299c129e92abeba5e

Just throwing $**t against the wall to what sticks

[squonk 41,067]

Did they at least install heavy enough wire to change it to 200 Amps? 

[ebinmaine 67,418]

7 minutes ago, squonk said:

Did they at least install heavy enough wire to change it to 200 Amps? 

I think so? But even if not, none of the wiring is very long so it could easily be replaced.  

[squonk 41,067]

I would find out and when 200 a components become available do it. Otherwise you be "Green Acres" all over again with electrical management. 

 

[ML3 1,197]

I know it's a big cost but insulation is important. I used rockwool insulation in walls of garage. It's very moisture & fire resistant. Also easy to work with, also expensive. My walls are finished inside with OSB. My ceiling is 2" insulation board with 8-10" blown in insulation in attic. My garage is detached 24'x24'. I installed 2 1500w 120v infrared heaters at a cost of $100 for both. Most the time I only need to use the 1 heater. If it starts getting down in the 20s outside then I may need the other heater to help. Electricity in my area isn't cheap but it's not over top expensive either. I think I'm going to invest in a mini split system that will heat & cool in the near future. I've been researching them & am surprised at how energy efficient they are. 

 

How important is it that you hear the upstairs? In my situation there's no reason to heat the attic so I didn't insulate the roof, just the ceiling of garage/floor of attic. 

 

40° to me is still  cold! 🥶 Lol! I can get my garage to over 65° in about half an hour with those infrared heaters. I do have a portable propane heater, benchtop kerosene heater, & a torpedo heater but I really haven't used them since I installed the infrared heaters. 

Edited November 13, 2023 by ML3

[JoeM 7,873]

EB  there is a big difference in wire cost 5000 watt to say 7500 watt. the wire cost almost doubles. 10/2 to 8/2

I run my outshop on a 100A service. I have a 240v compressor, welder, plasma cutter and a 5000 watt heater, ran that stuff for years and no issues. And I run them sometimes continuous.  

the 5000 watt heaters pull about 21 amp so #10/2 on a 30 amp breaker would be fine. 

The newer heaters have different heat settings and remote controls so they can be placed up on the ceiling and blow down. heat up quick too. 

When the weather gets cooler I will leave my heat on low over night or might have it up a touch if I am going to paint something the next morning, About a buck a day in the winter. 

 

[ebinmaine 67,418]

50 minutes ago, ML3 said:

How important is it that you hear the upstairs?

Upstairs is the dojo.  

YOU tell BBT she ain't getting a heated space. 

 

 

Really though....

The upstairs could get by most days without any heat because it'll travel up from the lower floor. 

 

[ML3 1,197]

13 minutes ago, ebinmaine said:

Upstairs is the dojo.  

YOU tell BBT she ain't getting a heated space. 

 

 

Really though....

The upstairs could get by most days without any heat because it'll travel up from the lower floor. 

 

Sounds like you will be heating the upstairs! Honestly a couple holes in floor maybe trimmed/covered with floor heat register vents, will help get heat upstairs??

My girlfriend has heat in her she shed so I understand. I also insulated that with rockwool. 

[wh500special 2,168]

4 hours ago, ebinmaine said:

 

Good catch Bob. 

They're $221 each plus wiring and breakers.  

 

I edited my post.  

 

 

Any specs or links?

 

Steve

[ebinmaine 67,418]

1 hour ago, wh500special said:

 

Any specs or links?

 

Steve

 

 

 

 

 

They also sell a 7500 watt model. 

That's around $135 I think.   

 

 

[ebinmaine 67,418]

2 hours ago, ML3 said:

insulated that with rockwool

That'll be the plan as we go. 

A barrier to catch and direct condensation from the underside of the metal roof. Then rock wool in the trusses. 

 

[squonk 41,067]

How big and how long is the service entrance is the key. If the wire is sized to just pass for a 100 Amp service there could be an issue. If it was upsized you may be ok. If the pole is 200' from the shop you get a big power loss. Your 100 A service may only be able to supply say  75 amps and the inrush of a compressor will take all that 

 

Back in my Napa days we had a customer who bought an old gas station He bought a big 3 phase compressor from us and it would blow a fuse on start up every so often. The fuse panel was on the other end of the shop. He had a "electrician friend"  run a bigger circuit. That solved the issue but now when that compressor started the neighbors lights would dim. The power co. had to install a bigger transformer on the pole and run bigger triplex to the building.

Edited November 13, 2023 by squonk

[ebinmaine 67,418]

31 minutes ago, squonk said:

How big and how long is the service entrance is the key. If the wire is sized to just pass for a 100 Amp service there could be an issue

Good questions for the power company and electrician. 

 

I know the distance is about 140 ft but wire size I don't know. 

 

 

[Racinbob 11,050]

Eric, here's my last 2¢ worth and what I'd do. Bite the bullet and upgrade to 200 amps. Also bite another bullet and insulate. I seriously doubt that the current wire size (pun intended ) is sized to do that so it will be pretty much a complete service changeover. You'll be happy in the long run. Propane, natural gas and wood are clearly out leaving only electric as your choice. I actually prefer electric. I've always loved a wood stove but it's messy and I'm getting too old to keep a supply of wood around. For us, propane is out. We simply don't like that it is heavy and can pool.

I don't remember the total size of your barn but I don't think it's overkill to use 3 of the units your looking at. You might find them struggling if you don't insulate. Replace your 100 amp panel with an appropriate 200 amp panel and run separate 60 amp circuits to each heater. Use #6 copper. Their Q&A mentions that #8 is OK but I'm old school. With over 50 years in the trade it was always code that #8 was good for 40 amps only. I'm staying old school there. Per the specs their 10000 watt heater is rated at 240 volts bringing the amperage to 41.7 amps. Most likely your voltage is closer to 220 with and, since it's a purely resistive load, would lower the amperage some but also the wattage and BTU output. That's irrelevant in this case. There, you're done and will be happy with it. You'll have plenty of go juice for your equipment and stay warm using it. Another nice thing about those Vevor units is that you can cut them down to 7500 watts. Once the building is warmed up I'd bet that will be plenty to maintain. 

[Racinbob 11,050]

7 minutes ago, ebinmaine said:

Good questions for the power company and electrician. 

 

I know the distance is about 140 ft but wire size I don't know. 

 

 

I would let the power company worry about that. It's their job. Remember that conductors run open air are somewhat different. 

[wh500special 2,168]

1 hour ago, ebinmaine said:

 

 

 

 

 

They also sell a 7500 watt model. 

That's around $135 I think.   

 

 

Thanks. 
I need a couple electric heaters at work and the price sounded good. 👍🏻

Steve

[Handy Don 12,211]

Great thread! I am enjoying the discussion. I’m setting up a workshop in a loaned, standalone 24x24 garage. Partly insulated. Since I’ll likely have this shop only for a year or so, I’m not making any significant investments.

 

Electric service is a 50 amp sub-panel overhead-wired from the main house and we have among the highest electric rates in the US. Electric heat is a non-starter. A 30-amp mini-split would be ~$1,000 all in.

 

I’ll likely use an indoor-safe variable 15,000  BTU propane radiant with a 20lb portable propane tank and accept the fuel cost.  I’m hoping to work for 4-5 hours a day and so full blast to take the chill off and then dial it back to keep it at 60º or so would be fine. Off when not there.

Edited November 14, 2023 by Handy Don

[ebinmaine 67,418]

2 hours ago, Handy Don said:

Great thread! I am enjoying the discussion. I’m setting up a workshop in a loaned, standalone 24x24 garage. Partly insulated. Since I’ll likely have this shop only for a year or so, I’m not making any significant investments.

 

Electric service is a 50 amp sub-panel overhead-wired from the main house and we have among the highest electric rates in the US. Electric heat is a non-starter. A 30-amp mini-split would be ~$1,000 all in.

 

I’ll likely use an indoor-safe variable 15,000  BTU propane radiant with a 20lb portable propane tank and accept the fuel cost.  I’m hoping to work for 4-5 hours a day and so full blast to take the chill off and then dial it back to keep it at 60º or so would be fine. Off when not there.

 

 

 

I've got a call into our friend the electrician.  

 

We're leaning towards a single electric heater with a propane space heater for additional help in colder weather.   

 

His answers and advice will determine the path....

 

 

[Handy Don 12,211]

7 minutes ago, ebinmaine said:

We're leaning towards a single electric heater with a propane space heater for additional help in colder weather.   

Technically propane is considered a liquid fuel by our codes, since it is delivered and stored in liquid form. Not sure how your insurance and other codes treat it.

Of course it “boils” into a gas as it’s being used in cooking, lighting, and heating appliances.

[ebinmaine 67,418]

14 minutes ago, Handy Don said:

Technically propane is considered a liquid fuel by our codes, since it is delivered and stored in liquid form. Not sure how your insurance and other codes treat it.

Of course it “boils” into a gas as it’s being used in cooking, lighting, and heating appliances.

 

Insurance isn't friendly to ANY non permanent heaters.  

Other codes don't state much.  

 

[wallfish 16,994]

Unvented propane heaters will add lots of humidity

Maybe anywhere from 1 lb of water per lb of propane burned to a ratio of 1.6 to 1.

Internet info

My windows would be dripping when I used it a lot