Hydronic Radiant Heating for Pole Barn - What is best heating source option

[lively1]

I am looking for some options for heating my 36 x 56 x 14 pole barn which will have a hydronic radiant heat tubing installed in the next couple of weeks. I will have a vapor barrier, 3" of foamular 250 insulation, wire mesh with 5/8" pex raised on risers to 2" and a 6" concrete pad. I plan on installing 1 to 2" of insulation on the edge of the pad before backfilling. Pex will be installed at 12" spacing. Ceiling and walls will be insulated, but not sure what R value yet - likely up to 30 on ceiling and 15 on walls. Climate is St. Louis, MO and the shop will only be needed to be heated to 60 degrees or so. Not a daily use shop, but I understand once you heat your mass you should maintain the heat. Also plan on having a finished loft 16x36 that I would like to heat and cool (could use mini split or window AC/heat unit or add radiant to the floor with a window AC). Currently electric rates for electric heating from my coop is at 6.2592 cents/Kwh.
We only have electric onsite and would rather stay away from adding a propane tank unless I am forced...

Some of the ideas I am floating right now:
1.) tankless electric water heater - Not sure longevity of this install as I have heard some people replacing fairly frequently.
2.) Geothermal - thinking water to water or a combination unit. I can install loop myself with help from friends and a backhoe, but would need to buy the unit and have a professional hookup. Also if installing a combination unit I could heat and cool the loft as well...Problem with this option is tax credits expired as of 12/31/2016...
3.) hybrid water heater or standard electric water heater - not sure if these units would keep up with the heat demand - experience anyone?
4.) Electric boiler - Cost for size needed and energy usage? Propane boiler if I have to for cost and efficiency.
5.) Would consider solar water, but not sure how it performs and the overall costs...
6.) Compost hydronic heating - install large compost pile and cycle water/glycol through manifold and pex tubing in floor...Jean Paine method - It's free (except mine and friend's time and labor) and usually lasts 12-18 months for heating... I only need about 4-5 months of heating...

Any help would be greatly appreciated. I would love to hear some of the costs associated to installing and operating some of the options above and whether you are satisfied with its performance.
Thanks.

 

[Radix2]

Wow, a lot of alternatives, but no definition of "best" - cheapest to build, run, simple, reliable, maintainance....

I'll give my opinions per number, and since you are doing a first class job getting your floor set up, I'll not assume cheapest is best...

1. No- get a electric "boiler" that is made for space heating...some tankless water heaters are certified as Ok, but make sure that the unit has low head losses so that you can do a simple loop. By the time you buy a restricted flow tankless HWH and add pumps and a pri-secondary loop, you could have bought a electric boiler.

2. A lot of cost and complexity and you are in a fairly warm climate. There are some rumors of companies bringing their air to water minisplit style heat pumps to the US, those would be a good fit imo.

3. No. Hybrid makes no sense at all for space heating...taking heat out of your space to put heat in your space removes all of the efficiency of hybrid. Regular tank ? Does it meet your BTU requirement, do you want to take up the space? Could be ok choice if you get a lifetime unit, but the similar cost to boiler.

4. Simplest choice, easy to pick based on your BTU req. you can easily calc the cost diff to propane, my guess is that in your climate, you probably don't want to mess with propane service just for this...wife want a gas stove...?

5. That is another hobby, put in a boiler first then play with your solar hobby.

6. Another interesting hobby, put in a boiler first and then experiment away!

IMO.

 

[MattN03]

I'm wanting to do the same thing on my future pole barn. I hope we hear some good feedback.

 

[Highbeam]

With electricity that cheap, just buy an electric boiler and don't look back. You didn't mention gas prices or desire for a fossil fuel boiler so we can't compare them.

 

[theoldwizard1]

... plan on having a finished loft 16x36 that I would like to heat and cool (could use mini split or window AC/heat unit or add radiant to the floor with a window AC).

Not for the "faint of heart" ... a multi-zone mini-split, with a refrigerant to water heat exchanger.

The loft can be heated and cooled by a regular air handler. Air handlers could be added to the shop for cooling (even after the install). These could also be used to help bring the area up to temp quicker.

This is not truly a "custom" system. Mitsubishi sells this exact system outside of the US ! The heat exchanger is an "off the shelf" item. You should be able to use a "standard" thermostat (except when heating the floor and the shop air - those 2 thermostat might not play nice together).


If you are going geothermal, do NOT use ground loops ! Wells may cost you more to install, but if the return water temp is too low (<50F), you can always drill another well.

I have read some other boards where HVAC techs have built their own geothermal, radiant heat, air cooling systems from available parts. Lots of parts, valves, copper pipe, heat exchangeres, etc. If you have the skill and know how to shop for parts, it is probably a good deal.

 

[theoldwizard1]

The simple solution is an electric boiler and then some solar panels and a mini grid tie inverter to help offset the operational costs.

 

[Ed Devinney]

Daikin does offer their Altherma air-water heat pump in the US - we considered it until we got ballpark pricing.

I second the photovoltaic solar panels. Looks like MO is net metering, so if you size it right you could effectively generate heat (electricity) all summer that you'll consume in the winter.

 

[walrus]

I have a friend who is importing mini split "boiler" from china(where else). He has 40 of them but is beta testing them as we speak. I think he is using them with convectors though and not full blown radiant floors. The nice part is with convectors they are reversible so AC in summer. 34,000 BTUs as far as heat goes.

I have solar hot water in my shop, it works great , keeps my shop from freezing, I'm sure it would work but the planning for it should have been done before building. My guess is in your climate you would get blown out of there most of the time.

Unless your electric rates are cheap I wouldn't use electric

 

[lively1]

If I go with electric boiler, I am assuming a modulating boiler, but what size and brand? I see them at Menards reasonably priced, but am concerned about quality...

 

[HoosierBuddy]

Two things come to mind.

The power costs are border-line unbelievable. Can you verify by taking your bill and dividing your total $ by KWH ? I guess I'd do it 2 ways. Straight and then do the same thing but subtract your customer charge first and then divide it by usage.

Second thing I guess I think is I personally would not use any source of resistance electrical heating because it is going to be about 4 times as expensive as a heat pump based solution for operational costs.

And...given the equipment costs associated with hydronic coupled with a heat pump...I'd likely just put in an air source heat pump system and forget about hydronic heating.

I love my hydronic setup but:

1. Even with NG available, buying equipment wholesale, and doing about 1/2 the installation myself it was expensive.
2. Seven years in I find I have maintenance costs prior to each heating season (lose a zone pump for example)...My forced air system in the house is much more reliable than my hydronic system in the garage.
3. The heat pump would give you a/c too...and sometimes my garage can be very hot in the summer.

Phil

p.s. To the OP...how on earth do you have a 2008 join date and this is your first post ever? Just curious.

 

[forAK]

p.s. To the OP...how on earth do you have a 2008 join date and this is your first post ever? Just curious.

LOL - caught that too. Some serious lurking, or 8 years of planning!

 

[lively1]

Both - serious lurking and lots of years of planning... I have a decent 3.5 car garage, but with kids stuff and vehicles, I decided it was time to build the man-cave/workshop I have always wanted...

On the geothermal-side - I am pretty sure I can install my loop for practically nothing (just tubing cost) so my major costs would be purchasing the geo unit...
Does geothermal water to water produce the heat needed for floor heat. I looked at jaredfloyd's post from his 40 X 60 Northwest Garage Build - he used it in his building... I have friends that are mechanical contractors that I can buy plenty of beer and could get some help installing...
Jaredfloyd's post:
http://garagejournal.com/forum/showthread.php?t=109088&page=5

 

[86turbodsl]

Well, being slab based, and temps required being lowish, i would say geo hydronic should work great. I do that in my house.

Sent from my SM-N910T using Tapatalk

 

[bzinsky]

hydronic in-floor with an electric water heater should be considered a sin.

All that work for the most efficient means of distributing heat possible, all negated by electric resistance heat

 

[bzinsky]

Both - serious lurking and lots of years of planning... I have a decent 3.5 car garage, but with kids stuff and vehicles, I decided it was time to build the man-cave/workshop I have always wanted...

On the geothermal-side - I am pretty sure I can install my loop for practically nothing (just tubing cost) so my major costs would be purchasing the geo unit...
Does geothermal water to water produce the heat needed for floor heat. I looked at jaredfloyd's post from his 40 X 60 Northwest Garage Build - he used it in his building... I have friends that are mechanical contractors that I can buy plenty of beer and could get some help installing...
Jaredfloyd's post:
http://garagejournal.com/forum/showthread.php?t=109088&page=5

By far the biggest hurdle with geothermal is the drilling/digging.

If you have an easy means of doing that, than absolutely do it

Geothermal source heat pump + in-floor radiant = holy grail of heating

and yes, they provide plenty of heat, but you'd want a heat pump. You wouldn't want to just circulate the 55 or so degree water from the ground through your garage floor. Your heat pump essentially ***** the energy out of the 55 degree water and then redistributes it to your hydronic loop, which can operate at much higher temps.

 

[Northislander]

Not for the "faint of heart" ... a multi-zone mini-split, with a refrigerant to water heat exchanger.

The loft can be heated and cooled by a regular air handler. Air handlers could be added to the shop for cooling (even after the install). These could also be used to help bring the area up to temp quicker.

This is not truly a "custom" system. Mitsubishi sells this exact system outside of the US ! The heat exchanger is an "off the shelf" item. You should be able to use a "standard" thermostat (except when heating the floor and the shop air - those 2 thermostat might not play nice together).


If you are going geothermal, do NOT use ground loops ! Wells may cost you more to install, but if the return water temp is too low (<50F), you can always drill another well.

I have read some other boards where HVAC techs have built their own geothermal, radiant heat, air cooling systems from available parts. Lots of parts, valves, copper pipe, heat exchangeres, etc. If you have the skill and know how to shop for parts, it is probably a good deal.

Wizard curious when not knowing the OP's ground conditions you would steer him away from a ground loop? In my opinion if he's willing to spend the dollars geo would be the most economical option in the long run.
Horizontal loop or vertical is determined by the ground conditions.

 

[lively1]

I was wondering the same thing about steering away from ground loop. In my house I have a geothermal system that is a horizontal ground loop system. I am very satisfied with it. It is not a water to water unit, but a water to air.

 

[lively1]

OK, so it has been almost a year and I have not pulled the trigger on any heating option for the barn... Just been busy finishing out the inside. I almost have all the insulation complete and just finished insulating the large doors. I am hoping to really just ask the same original question I previously posted to get some input from people on their experiences with the options I am proposing. See a description of the building and the options I am looking at below:

So to describe the pole barn and it’s construction – 36’x56’ with 14’ sidewalls. It has a 6/12 pitch with no ceiling. Total height to roof peak is 23’. We have a little insulation between the metal and wood roof framing – likely a R10 rating up to R-13. I may put in a ceiling and add more insulation in the future, but no plans for that at this time. Walls are insulated with fiberglass insulation at a R19 rating and have an exterior osb-sheeting on the inside with some added R value. The 6” concrete pad is insulated underneath with 3” foamular 250 with R value of R15 and on the sides of the pad with 1 or 1-1/2” foamular 150 with insulation value of R5 or R7.5. There is two large 14x18 sliding doors that are insulated with an R value of 10 to 13. There are plans to seal up the large doors with brush seals to eliminate any drafts and gaps. There is a single man-door that is metal and insulated with a small window. There are also 7 windows and a transom window that are double pane vinyl with an estimated area of 72 ft2. I do have vented soffits, however I am covering it up during the winter with the extra 3” foamular insulation that I place in the eaves. I also have a ridge vent, but I believe most of it is ineffective as the insulation between the metal and wood roof framing covers it up… The oxygen barrier pex tubing was installed at approximately 12” spacings and placed near the center of the concrete pad on chairs. There is 10 250’ loops of the pex leading to the manifold system. I do have plans to add a 16’x36’ loft on the east end of the barn. My thoughts for this loft were to heat it with the pex tubing as I have an extra manifold and could install the tubing while installing the loft in the future… So I would like to have some future ability to add this to the system.

Some of the things I am considering are:

• I want something to keep it warm in the building – I am guessing I will keep it 50 degrees most of the time and may consider cranking it up if we are hosting a party out there or if I plan on hanging out there for a period over a weekend, but this would not be very often. Also want an option to heat domestic hot water as well versus having to have a separate hot water heater. This is not a deal breaker, but a prefernace. Understand that a slab heat system needs time to warm up and you cannot just crank up the heat and expect instant results.

• Electric boiler – need an estimate of what Kw boiler it would take to keep building warm. Also estimate on cost of running the unit in the winter time given that I want to keep building at 50 degrees. We pay $0.06/Kw for electric heat during the winter. This would be the easiest option as I would not need to have to bring in propane and I have 100 amps in building and planned for 50 amps for a heater of sorts.

• Propane boiler – need a good estimate on size and cost to operate ($1.55/gal propane). Want to make sure it is a micro boiler, condensing and modulating. Must have an outside temperature reset and would prefer one that has a great heating reduction rate and a great efficiency 95% or greater. Would prefer one that could make domestic hot water as well.

• Water to Water Geothermal or an air to water heat pump option – would consider one of these options as well, but am guessing cost is out of budget here. These may be the most efficient for operation and would require only electric, however they may be the most complex to install and operate. I have resources to install the loops if geothermal was an option which could reduce install costs. I am intrigued by the air to water heat pump option as it could also give me an option to cool if I added an air handler.

 

[Bondo]

Some of the things I am considering are:

• I want something to keep it warm in the building – I am guessing I will keep it 50 degrees most of the time and may consider cranking it up if we are hosting a party out there or if I plan on hanging out there for a period over a weekend, but this would not be very often. Also want an option to heat domestic hot water as well versus having to have a separate hot water heater. This is not a deal breaker, but a prefernace. Understand that a slab heat system needs time to warm up and you cannot just crank up the heat and expect instant results.

• Electric boiler – need an estimate of what Kw boiler it would take to keep building warm. Also estimate on cost of running the unit in the winter time given that I want to keep building at 50 degrees. We pay $0.06/Kw for electric heat during the winter. This would be the easiest option as I would not need to have to bring in propane and I have 100 amps in building and planned for 50 amps for a heater of sorts.

• Propane boiler – need a good estimate on size and cost to operate ($1.55/gal propane). Want to make sure it is a micro boiler, condensing and modulating. Must have an outside temperature reset and would prefer one that has a great heating reduction rate and a great efficiency 95% or greater. Would prefer one that could make domestic hot water as well.

• Water to Water Geothermal or an air to water heat pump option – would consider one of these options as well, but am guessing cost is out of budget here. These may be the most efficient for operation and would require only electric, however they may be the most complex to install and operate. I have resources to install the loops if geothermal was an option which could reduce install costs. I am intrigued by the air to water heat pump option as it could also give me an option to cool if I added an air handler.

Ayuh,....... With yer compost pile heater idea, just how much land do ya have there,..??
Any of yer land forested,..??

I ask, 'cause I see no mention of a wood fired boiler,......
Combined with heat storage tanks, ya might get by with 1 good burnin' a week,.......

I heated an ole 100 year old farmhouse you could throw a cat through the air gaps in, for 10 years, 'n all it cost me was abit of sweat,......
I did it with a homemade boiler that I built outa dumpster scrap,.....
The newer wood boilers have become very efficient, 'n would burn probably 1/2 of the cordage I burnt in mine,.....

Down where you are, heat storage, 'n less burns might work for ya,.....
Up here, 0*, 'n below are normal winter temps,......
My fire burned from Sept. to May,.....

I've since moved into my lakeside 100+ year old cottage, 'n heat with a little Weil/ McClean oil boiler, 'n my designed retro-fit in-floor radiant,....
Workin' on my propane backup system,.....
Power outages are to common to rely on only electric heat out here,....

 

[Black Oak]

I'm straight south of you in Ark . just below the "boot heel" , I really think a good, properly sized mini split will cover your needs . A supplemental hanging heater { elec. or propane} for the few extremely cold days that is used as needed. I got to Ark. with big thoughts on my winter needs, and the old timers around here chuckled. The point is , get a propane boiler and you won't use that much fuel IMHO . In tandem with a mini split , it won't work that hard , given the insulation you have .

 

[Jackfre]

Daikin does offer their Altherma air-water heat pump in the US - we considered it until we got ballpark pricing.

I second the photovoltaic solar panels. Looks like MO is net metering, so if you size it right you could effectively generate heat (electricity) all summer that you'll consume in the winter.

Daikin has pulled the Altherma from the US market.

 

[Firebrick43]

Daikin has pulled the Altherma from the US market.

Do you know why? I have been waiting for an air to water mini split but couldn't wait anymore.

 

[krom]

Do you know why? I have been waiting for an air to water mini split but couldn't wait anymore.

check out these guys
chiltrix.
noraire

It won't let me post links yet, but google should come up with them easy