That1Guy
Well-known member
**Wow! I apologize for such a long post - I had no idea until I was done typing that it was so long. Click away - save yourself! It goes on for days...
You've been warned.
My pole barn is 32 x 32 x 12. I put 2" of foamboard under the 4" slab with 4 300' loops of pex. The walls were sprayed with 2-3" of closed cell foam and finished with fiberglass batt and drywalled. The ceiling is steel durapanel and soon to have 20" of blown cellulose. No windows, a 12 x 12 OH door and an 8x8 OH door and a man door.
All the electrical is being done in surface mount EMT because I am tying to avoid any penetrations to the walls or ceiling. For the same reason, I went with an electric DWH as a heat source (no gas line or exhaust pipe going through the walls or ceiling) and, so far the electric DWH is doing a great job. I realize we haven't had any cold days yet and the ground hasn't frozen but it has brought the air temp to 75 on a 37 degree day even without any insulation in the attic yet.
Of course, after reading countless threads on this subject, and hearing so many of you pointing out how much more expensive heating with electric is than gas, I'm feeling a bit of panic welling up. I just fired it up two weeks ago and so, of course, we've yet to see an electric bill. And even when we do see the bill for October later next week, it will only reflect about half of October, again without much cold weather. It won't be until December that we will even see full month bill and this is where the panic begins to set in.
I'm rethinking my zero penetration rule (don't even go there
) and have been looking at tankless NG water heaters to replace this electric tank unit. I've decided to go the condensing route both for better efficiency and also so I can vent out the wall instead of the ceiling and roof (one of those "lesser of two evils" things). I'll need to run a gas line from my meter, around the side of the house and garage and back to the pole barn - a 100' run. I'll have to go through a sidewalk and a crumbling old asphalt driveway but it's very doable. I hate to rush into this now, without even seeing what the electric is going to cost me, but I also don't want to find out, mid winter, that I cannot afford to run the electric all winter (retired on a budget aka brutha broke!). I think I might just run the gas line to the shop now and cap it off until I eventually buy a gas unit. Better safe than sorry. That way, if the electric does prove to be undoable, I wont be trying to trench through frozen Michigan clay and connecting a gas line when it's 20 degrees outside so there's that.
OK, I say all of that to say this... (sorry I ramble when I go on about my shop... ). I typically tend to just dive right in without testing the waters sometimes and to be honest, I didn't do any heat calcs or run any numbers while putting this together. I did what I could afford, as I could afford, and did most of the work myself. It wasn't until I was already neck deep in this project that I started reading threads about the more scientific approach to this radiant heat thing. Oops. That could come back to bite me for sure. But hopefully, I've insulated enough that I should be OK. Fact is, the shop is probably going to end up being twice as efficient as the house is so again, I hope it'll all be OK.
If you're still reading this painfully long post (literally painful - my old fingers are killin me from all this typing) then you're either a glutton for punishment or perhaps you might be able to lend some advice. I'm currently looking at the Takagi T-H3M-DV-N. I picked this one because (shocker) it's the cheapest condensing high efficiency unit that I've found that also has great reviews and a handful of YouTube videos of other people using them to heat a slab and they've been very happy with it. Spec sheet says it modulates between 15K and 120K btus.
So, with all of the info I have jotted down here, can anyone tell me if this Takagi unit would be enough to keep my shop heated? Yeah, I know I'm asking a lot, especially without having run any heat calcs or whatever other formulas and algorithms I should have done before beginning. I guess I'm just looking for a ballpark guesstimation or opinion - lol. Or maybe I'm seeing if anyone says "No way bro! That's not gonna work for your application" or something similar. Of course they have to include some logical reasons to make me change my mind though - lol. But I'm open to any and all suggestions or critiques. I'm confident in that Takagi unit but I'm also perfectly aware that I don't know what the hell I'm doing here... So yeah, I'll take any advice I can get thankyouverymuch!
My "plan" is to keep the air temp around 50 - 60 degrees all winter. Here in Michigan, that's dang near t-shirt weather once we've been acclimated. If for some reason I do need it warmer out there, I have one of the manifold circuits set aside for a water-to-air exchanger with a squirrel cage fan to give it a boost when needed. I don't see it being a problem but again, I welcome any and all comments and suggestions. Thank you for any input you may offer and also thank you for reading this ridiculously long winded post. What is wrong with you? You should have bailed a few paragraphs ago. I better put a warning at the beginning.
You've been warned.
My pole barn is 32 x 32 x 12. I put 2" of foamboard under the 4" slab with 4 300' loops of pex. The walls were sprayed with 2-3" of closed cell foam and finished with fiberglass batt and drywalled. The ceiling is steel durapanel and soon to have 20" of blown cellulose. No windows, a 12 x 12 OH door and an 8x8 OH door and a man door.
All the electrical is being done in surface mount EMT because I am tying to avoid any penetrations to the walls or ceiling. For the same reason, I went with an electric DWH as a heat source (no gas line or exhaust pipe going through the walls or ceiling) and, so far the electric DWH is doing a great job. I realize we haven't had any cold days yet and the ground hasn't frozen but it has brought the air temp to 75 on a 37 degree day even without any insulation in the attic yet.
Of course, after reading countless threads on this subject, and hearing so many of you pointing out how much more expensive heating with electric is than gas, I'm feeling a bit of panic welling up. I just fired it up two weeks ago and so, of course, we've yet to see an electric bill. And even when we do see the bill for October later next week, it will only reflect about half of October, again without much cold weather. It won't be until December that we will even see full month bill and this is where the panic begins to set in.
I'm rethinking my zero penetration rule (don't even go there
) and have been looking at tankless NG water heaters to replace this electric tank unit. I've decided to go the condensing route both for better efficiency and also so I can vent out the wall instead of the ceiling and roof (one of those "lesser of two evils" things). I'll need to run a gas line from my meter, around the side of the house and garage and back to the pole barn - a 100' run. I'll have to go through a sidewalk and a crumbling old asphalt driveway but it's very doable. I hate to rush into this now, without even seeing what the electric is going to cost me, but I also don't want to find out, mid winter, that I cannot afford to run the electric all winter (retired on a budget aka brutha broke!). I think I might just run the gas line to the shop now and cap it off until I eventually buy a gas unit. Better safe than sorry. That way, if the electric does prove to be undoable, I wont be trying to trench through frozen Michigan clay and connecting a gas line when it's 20 degrees outside so there's that.OK, I say all of that to say this... (sorry I ramble when I go on about my shop...
). I typically tend to just dive right in without testing the waters sometimes and to be honest, I didn't do any heat calcs or run any numbers while putting this together. I did what I could afford, as I could afford, and did most of the work myself. It wasn't until I was already neck deep in this project that I started reading threads about the more scientific approach to this radiant heat thing. Oops. That could come back to bite me for sure. But hopefully, I've insulated enough that I should be OK. Fact is, the shop is probably going to end up being twice as efficient as the house is so again, I hope it'll all be OK.If you're still reading this painfully long post (literally painful - my old fingers are killin me from all this typing) then you're either a glutton for punishment or perhaps you might be able to lend some advice. I'm currently looking at the Takagi T-H3M-DV-N. I picked this one because (shocker) it's the cheapest condensing high efficiency unit that I've found that also has great reviews and a handful of YouTube videos of other people using them to heat a slab and they've been very happy with it. Spec sheet says it modulates between 15K and 120K btus.
So, with all of the info I have jotted down here, can anyone tell me if this Takagi unit would be enough to keep my shop heated? Yeah, I know I'm asking a lot, especially without having run any heat calcs or whatever other formulas and algorithms I should have done before beginning. I guess I'm just looking for a ballpark guesstimation or opinion - lol. Or maybe I'm seeing if anyone says "No way bro! That's not gonna work for your application" or something similar. Of course they have to include some logical reasons to make me change my mind though - lol. But I'm open to any and all suggestions or critiques. I'm confident in that Takagi unit but I'm also perfectly aware that I don't know what the hell I'm doing here... So yeah, I'll take any advice I can get thankyouverymuch!
My "plan" is to keep the air temp around 50 - 60 degrees all winter. Here in Michigan, that's dang near t-shirt weather once we've been acclimated. If for some reason I do need it warmer out there, I have one of the manifold circuits set aside for a water-to-air exchanger with a squirrel cage fan to give it a boost when needed. I don't see it being a problem but again, I welcome any and all comments and suggestions. Thank you for any input you may offer and also thank you for reading this ridiculously long winded post. What is wrong with you? You should have bailed a few paragraphs ago. I better put a warning at the beginning.
I used about 145 gallons of propane for my 36x80 garage