In-Floor Heating for a Shop & Greenhouse - Considerations ?

[Rustyiron]

How do you "top" the vertical form board around the perimeter?

A lot of people cut the top edge of the foam at a 45* angle with the "point'' being at the top of slab.

 

[dstig1]

Great tips on setup. And identifies it makes sense to get an expert providing some on-site advice.

Is the vertical 2" foam board just covered with dirt or ...?

Michael

Mine is covered with dirt. The top of it was exposed so I had the siding crew bend some heavy metal flashing down over the top of it. Termites are not a big thing up here so I wasn't especially worried about that either.

 

[civilian]

Late to the party. My county building inspector will not allow DHW heaters to be used as floor heat boilers. I also start the flow in the floor in October before the days start getting colder. My pex is filled with RV antifreeze. Jon

 

[dstig1]

I could understand if they did not want a SHARED DHW heater being used for the floor along with domestic (potable) HW, but if it is dedicated to the floor then he has no business saying no, frankly. Heat is heat. Or just don't tell him and put it in later...

 

[5030]

Just so happens the local building inspector is a good friend of mine and has been in my shop numerous times and has seen my dedicated HWH as well as my Calaffi distribution system and has never said boo crap about it. In fact he wanted the particulars as he's building a new pole structure and wanted to see how mine operates. Floor is presently running at 70 degrees, fully heated and the HWH basically idles 75% of the time.

Hard to beat a warm concrete slab IMO.

 

[rScotty]

Just so happens the local building inspector is a good friend of mine and has been in my shop numerous times and has seen my dedicated HWH as well as my Calaffi distribution system and has never said boo crap about it. In fact he wanted the particulars as he's building a new pole structure and wanted to see how mine operates. Floor is presently running at 70 degrees, fully heated and the HWH basically idles 75% of the time.

Hard to beat a warm concrete slab IMO.

I also use a dedicated HWH - it's a Marathon brand fiberglass/epoxy tank. The tank will probably outlast the house. My inspector was intrigued by that as well as other custom features.

Around here, the basics of any structure has to be approved by an engineer in order to get a building permit. The inspector is basically checking to see that the approved design has been followed, and that subcontractors are following codes. He would need very good reasons to turn something down....
rScotty

 

[5030]

In as much as my machine and fabrication shop is contiguous to the farm and here in Michigan farm structures don't need to be permitted, they only need to be built to existing farm building codes, I never had to apply for a permit, same for my Clearspan Truss arch building I store all my equipment and excess hay bales in.

Additionally, my propane fired HWH is sitting on the slab, not elevated in any way and has been that way for the last 8 years at least and while I don't run gas powered equipment in the shop I do use flammable compounds in it all the time and never had issue one. There are 3 motorcycles with full fuel tanks sitting adjacent to the HWH as well.

I don't ascribe to paranoia and never have. I do practice due diligence however. The shop is equipped with large sized American Lafrance ABC fire extinguishers that I have recertified every year. One in the front bay and 2 in the back bay.

Nice thing about running Cryotek in the system is, the HWH tank will never suffer the effects of internal corrosion so barring maybe a faulty thermocouple, it will far outlast me and the entire system is 100% full at all times and any entrapped air produced by the heating of the Cryotek is automatically expelled by any of the three in system trapped air removers. One in the main (from the HWH) feed line and one each on the hot side and cold (return side) of the system. I keep the static pressure in the system at 15 pounds on the supply side and 5 pounds on the return (cold) side and I monitor the system pressure with a pair of analog combination Watts temperature and pressure gages so I know exactly what the output pressure and fluid temperature is at all times as well as the return temperature and pressure is, not that I look at them much because the system maintains itself now and when I put it together I added a tempering valve setup off the HWH so I can intermix the feed (hot fluid) with the cold fluid. I have it set and have not fiddled with it in years now.

It's 100% turn key and it stays energized constantly through every season. I let it decide (via the in the slab remote sensing thermostat) when it needs to heat or not heat the slab.

 

[rScotty]

In as much as my machine and fabrication shop is contiguous to the farm and here in Michigan farm structures don't need to be permitted, they only need to be built to existing farm building codes, I never had to apply for a permit, same for my Clearspan Truss arch building I store all my equipment and excess hay bales in.

Additionally, my propane fired HWH is sitting on the slab, not elevated in any way and has been that way for the last 8 years at least and while I don't run gas powered equipment in the shop I do use flammable compounds in it all the time and never had issue one. There are 3 motorcycles with full fuel tanks sitting adjacent to the HWH as well.

I don't ascribe to paranoia and never have. I do practice due diligence however. The shop is equipped with large sized American Lafrance ABC fire extinguishers that I have recertified every year. One in the front bay and 2 in the back bay.

Nice thing about running Cryotek in the system is, the HWH tank will never suffer the effects of internal corrosion so barring maybe a faulty thermocouple, it will far outlast me and the entire system is 100% full at all times and any entrapped air produced by the heating of the Cryotek is automatically expelled by any of the three in system trapped air removers. One in the main (from the HWH) feed line and one each on the hot side and cold (return side) of the system. I keep the static pressure in the system at 15 pounds on the supply side and 5 pounds on the return (cold) side and I monitor the system pressure with a pair of analog combination Watts temperature and pressure gages so I know exactly what the output pressure and fluid temperature is at all times as well as the return temperature and pressure is, not that I look at them much because the system maintains itself now and when I put it together I added a tempering valve setup off the HWH so I can intermix the feed (hot fluid) with the cold fluid. I have it set and have not fiddled with it in years now.

It's 100% turn key and it stays energized constantly through every season. I let it decide (via the in the slab remote sensing thermostat) when it needs to heat or not heat the slab.

That's about how I built mine to be controlled. So that I could leave the house and shop for a 6 month vacation somewhere warm and this place would stay at good temps.
My hookup for a propane-fired backup is outside in an attached room.

 

[mikester]

Do you lay the pipe to avoid expansion joints on your slabs? How sensitive is the pipe to cracks in the concrete floor?

 

[Rustyiron]

Cracks don't seem to matter. A heaving situation would obviously be trouble but if your to that point, your already screwed.