Experience with pole barn heating

hkhi · Aug 29, 2012

All - Just started my 56x40 pole barn and am looking for some input on pros and cons of heating options.

Relevant information - Framing is 6x6s, 8ft apart. 12 foot ceilings, with attic trusses, total building height is around 22 feet to the peak. The walls will be metal, but I am planning to insulate. Floor will be concrete slab.

Since the barn will be used for mostly storage and workshop, I don't want to heat it all the time. Something that will get the inside up to 40-50F when it's 0F outside in 20 minutes would be ideal.

I think my options are warehouse style ceiling mount electric heaters OR radiant heat in the slab using wood/propane boiler OR an inside woodstove OR propane/kerosene salamanders. I've spent enough time breathing in the exhaust from propane salamanders to consider that the last option.

Anyone have experience with one or more of these?

Thanks,
-H

dave1949 · Aug 29, 2012

Radiant heat will accomplish nothing in 20 mins. It is better used for holding a constant temperature, you would need to keep the building at 40-50 all the time or wait several hours.

Do you want to prevent the inside temperature from dropping below freezing?

The ceiling hung electric heaters do work, have fairly low initial costs,have thermostats, adjustable air louvers, can easily be aimed a particular work area within reason, but don't look at your electric meter while they are on--you will run for the breaker :laughing:

Redneck in training · Aug 29, 2012

Here is one well excuted garage, shop building.
DeSoto Solar Passive Heating Panel Installation

KennyG · Aug 29, 2012

I'm in the process of rehabbing a 40 x 48 (12 ft ceiling) so I'm in about the same situation. After talking to a lot of people with heated pole buildings, I've more or less settled on a small (45k btu) hanging gas heater (I already have natural gas in the building) and a medium sized wood stove (80k ot 90k). My thought is that I can keep above freezing with the gas heater if I want, run both gas and wood to bring the temperature up, and keep the temperature up when I'm working with the wood stove only to minimize cost.

The full capital cost should only be about $1500 and operating expenses will be low.

Electric would only make economic sense if you intend to heat it only a very limited amount of time.

dave1949 · Aug 29, 2012

KennyG said:
........................

Electric would only make economic sense if you intend to heat it only a very limited amount of time.

I have a G73 Dayton brand ceiling hung electric heater in my garage. Dayton G73 Electric Utility Heater - Hobby Greenhouse Heating | Greenhouse Megastore

My thought was if it was really cold, it would knock the chill out of the air. I have it aimed at my tractor parking spot. As it turns out, I never use it because the building stays warmer than I thought it would. I turn it on 10 mins. every fall to burn the dust off :laughing:

At the full 17,000 btu rate, it will use about 5 kw per hour. So, at 15 cents per kwh, it costs me roughly 75 cents per hour to run at max. In reality, the thermostat will turn off the heat elements off and on, the fan keeps running. The cost would usually be less than the maximum. My electric meter just isn't used to that shock!

hkhi · Aug 30, 2012

dave1949 said:
I have a G73 Dayton brand ceiling hung electric heater in my garage. Dayton G73 Electric Utility Heater - Hobby Greenhouse Heating | Greenhouse Megastore

My thought was if it was really cold, it would knock the chill out of the air. I have it aimed at my tractor parking spot. As it turns out, I never use it because the building stays warmer than I thought it would. I turn it on 10 mins. every fall to burn the dust off :laughing:

At the full 17,000 btu rate, it will use about 5 kw per hour. So, at 15 cents per kwh, it costs me roughly 75 cents per hour to run at max. In reality, the thermostat will turn off the heat elements off and on, the fan keeps running. The cost would usually be less than the maximum. My electric meter just isn't used to that shock!

Wow. 75 cents for an hour isn't bad. How did you insulate your building to keep it warmer than expected?

DJ54 · Aug 30, 2012

The biggest problem will be the cold concrete floor, if not heated all the time. In the present shop, I have a waste oil furnace. When I'm not working in there, I set the thermomostat at about 50 degrees. Bump it to 65 or so if I am. Warmer if I'm painting, or woodworking finishing. The shop is 36' X 32'. I use approx. 450 gallons of oil per year, and it is a 120,000 btu furnace. Metal siding inside, with 1-1/2" styrofam panels in the walls and ceiling.

Building a new shop at present. Only 30' X 32'. But using a wood/coal stove, plus my waste oil furnace, as used oil is getting tough to find, with everyoine seemingly having a WOF now.

Many around here are now using the floor type radiant heat. Some gas, some plumbed to outdoor boilers. Most are farm shops, or business's. The ones with gas, most likely have a gas well or two on the property. Lucky them..!!

dave1949 · Aug 31, 2012

hkhi said:
Wow. 75 cents for an hour isn't bad. How did you insulate your building to keep it warmer than expected?

It is a passive solar building with a full earth berm on the north side that wraps around one-half of the west end.

I have seen it flirt with freezing overnight just once in six years during a cold and cloudy stretch. Our usual weather pattern is for clear and cold to happen together with a high pressure system.

In a normal winter on a cloudy winter day and overnight it will be around 40*, and 55* - 60* on a sunny day. It surprised me that it does as well as it does. The core temperature changes very slowly in bermed buildings with concrete floor and walls. Last winter was milder on average, it was about 5* warmer inside than usual.

I used 18" of fiberglass in the ceiling. Two crossing layers of 9" batts. Before I put the up the ceiling and ceiling insulation in the building, it could not be warmed up with something less than a construction site heater. That made me a big believer in well-sealed and insulated ceilings as being where you get the most bang for your insulation buck.

No matter what building it would be used in, the G73 heater would not use more than 5 kw per hour. So, that part holds true for you, but your heat loss may be greater and that would reduce the interior temperature. The G73's 17,000/hour is not a lot of btu's. My guess is that it would be good for heating an area while you are working, but won't do much total building wise for a pole barn.

radioman · Aug 31, 2012

probably the easiest and cheapest option is use a used house furance that runs on gas and run ducts to spots where you think you will be working all the time.

art · Aug 31, 2012

We just added on to our shop in central ny and there is nothing like insulation as our older building as well as the new is with 6" walls and fully insulated there as well as 16" in the ceiling. Doors closed the it only gets to about 72 on hot days and if the furnaces go out it takes over 48 hours to go to 40 degree's My preference is spray-on although the costs are higher the benifit of every crack filled is high! You made mention of the heated floors, also my preference but if you let it cool down, in about three days in central NY the lines might be freezing and then you have PROBLEMS!

wedge40 · Aug 31, 2012

I'm a huge fan of radiant heat, but if you're only going to heat it once in a while, I wouldn't even consider that idea. If the slab is cold or worse frozen you're looking at a day or more to bring the temp up. Are you going to section it off any? That would help in heater placement as well.

By the way I have the exact type building 40'x56'x12' with attic trusses and I'm planning on radiant heat at some point so I'm putting the pex in now and not sure when I'll put the reasf of the system in. I'm not sure just how much of the attic I'll finish or use yet either, but figure I'll use radiant up there as well.
Good luck.
Oh ya.. We like photos around here. LOL

Wedge

Redneck in training · Aug 31, 2012

art said:
We just added on to our shop in central ny and there is nothing like insulation as our older building as well as the new is with 6" walls and fully insulated there as well as 16" in the ceiling. Doors closed the it only gets to about 72 on hot days and if the furnaces go out it takes over 48 hours to go to 40 degree's My preference is spray-on although the costs are higher the benifit of every crack filled is high! You made mention of the heated floors, also my preference but if you let it cool down, in about three days in central NY the lines might be freezing and then you have PROBLEMS!

Floor heating is filled with glycol/water mix. It will not freeze until about -40F.

KennyG · Aug 31, 2012

dave1949 said:
It is a passive solar building with a full earth berm on the north side that wraps around one-half of the west end. ....
No matter what building it would be used in, the G73 heater would not use more than 5 kw per hour. So, that part holds true for you, but your heat loss may be greater and that would reduce the interior temperature. The G73's 17,000/hour is not a lot of btu's. My guess is that it would be good for heating an area while you are working, but won't do much total building wise for a pole barn.

Dave, it sounds like you did a really good job on that building. My guess is that a conventional insulated pole barn should have at least30,000 btu per 1000 square feet just to get over 50 degrees and probably twice that if you want to be able to get to "room temperature" in cold weather.

dave1949 · Aug 31, 2012

KennyG said:
Dave, it sounds like you did a really good job on that building. My guess is that a conventional insulated pole barn should have at least30,000 btu per 1000 square feet just to get over 50 degrees and probably twice that if you want to be able to get to "room temperature" in cold weather.

It's one of those pay me now or pay me later deals. Passive buildings are a lot more expensive to build than a pole barn. Also, making them more than about 28' deep north to south at my 44 degree latitude will put the sunshine input to concrete floor ratio out of balance.

It doesn't matter how long they are east to west as long as there is plenty of south-facing glass. But, that forces the building into a long rectangle shape which, if taken too far, gets expensive due to the ratio of perimeter wall to square feet of floor space. My building is 28 x 48 with a 10' ceiling. Sadly, it is full.

Maybe an ideal northern setup would be a passive style workshop building connected on the south-east corner of a larger pole barn that is used for equipment storage. The pole barn would buffer the workshop from prevailing westerly winter winds and the summer heat gain typical on the west end of a building.

Rustyiron · Aug 31, 2012

I love my radiat slab, no cold floors with all the heat up against the ceiling, and no "recovery" time after opening a garage door! But deffinetly not for intermittant use. Insulation is job #1 for any heated space. Blow the budget on your insulation pkg. and it will pay you back with what ever heating sys. you use!

Redneck in training · Aug 31, 2012

We completed construction of my new shop this spring. I was contemplating floor heating (we have in the house) but at the end I decided against it due to large temperature time constant. I figured that I would have to heat it at higher temperature resulting in higher energy cost. I would also like to have air conditioned in the summer. Geothermal system would add about 30K to the cost while air/air heat pump will cost at least twice as much to operate. Therefore I decided to use larger split unit heat pump at cost about 10K that I can instal by myself and use the remaining 20K to purchase extra about 10 kW solar panels also DIY. If I would want to use in example geo I would have to pay cash for the extra expense. If I want to add solar system I can finace it at very reasonable interest and get substantial tax write off. Right now I am trying to secure a loan for proposed 23 kW solar system and hoping to have installed before coming winter. I might also add passive solar heating to the shop sometime next year.

Smokepole62 · Sep 1, 2012

Whether you run radiant heat or not, take the time to properly insulate the footer and floor. Go extra thick on the insulation as you may want to heat full time later.
Don't know how far north you are located, but a coal stove may be a cheap option if your close to PA. It may be cheaper to semi heat full time and then turn up
when you need it as others have stated. Personally, I'de rather stay above 50 Deg. so my tools don't sweat when the temps increase. A coal stove might only burn
a couple of ton a year and be cost effective using a thermostat to run all winter. Good luck.

Rustyiron · Sep 1, 2012

Redneck in training said:
proposed 23 kW solar system .

Thats a lot of juice! Will you be selling back to the grid? Or is a "solar" KW not the same as a power Co. KW?

Redneck in training · Sep 1, 2012

Rustyiron said:
Thats a lot of juice! Will you be selling back to the grid? Or is a "solar" KW not the same as a power Co. KW?

We live in 100% electric house so 23 kW system in our location will cover about 75-80% of total consumption. According to calculation using PVwatt http://www.nrel.gov/rredc/pvwatts/grid.html it will produce about 31000 kWh/year. Right now we burn little less than 40000 kWh/year. About 65% of the consumption is heating/cooling. Since we added shop this year it might go up another 10000 kWh/year. The required size of the system shocked me too. I wish I could afford bigger one to cover the whole consumption. I decided to use Enphase inverters so adding more panels later on is relatively straightforward process.
Since Iowa doesn't require installation by licensed professional (only inspection is required) to qualify for the tax rebate I can do it by myself. At current prices of the panels and associated hardware I estimated payback at about 11-12 years after the tax rebate. I figured that to add power generating capacity is cheaper than installation of geothermal heating/cooling for the shop. I wish it was the case when we built our house in 2004.