What are the pros/cons of radiant floor heating?
#21
Wish you could come visit my shop and see the actual truth in owning a hydraunic radiant floor heat setup in a shop.

Here are my facts not guesses

7 degrees at 7am this morning outside
Shop was 57 degrees with no lights on
Its 40x64x16 pole barn - my own personal warehouse big I assure you when its just a tool and plywood shop - no planes or semis, just a scissor lift and tractor with forks as building tools for now
Electric Boiler is set to 109 degrees - 24kw $360 instant hot water heater from amazon deal - has three elements it uses as needed to deliver heat based on inlet temp of water temperature you put into it
~2600' of 1/2" pex in 9 loops in the middle of 2560sqft of 5" concrete all one zone - pex and manifold was about $1000
2" closed cell extruded poly styrene foam under concrete reused from roofers and 10 mil vapor barrier ~$500
I spent $800 on my.panel parts and awesome pumps and built it myself and its way nicer than the $2700 one I copied pre made. Its a two loop setup and controls delta of temp of water entering boiler by using a mixing valve to dump the small primary loops hot water into the cold water from floor before entering boiler.
Inzulation is most important no matter what you use.
I have 3"-4" closed cell 2lb spray foam on ceiling and gable ends (wish it was everywhere) and r19 batt on walls. $10,500 total between too and that includes install of spray foam

In floor temp probe measuring temp
Thermostat is turning on pumps when floor temp probe spot's temp drops below 62
Room at 5' up on south wall and the spot on one of my tool box on noth wall reports 57 degrees.

I can move two 14'x14' roll up insulated doors up and down and have two little girls running in and out playing in snow and hide and seek for hours and I cant tell the difference in temperature while I am there.

That was a funny joke about the hot floor feet temps or someone should visit a doctor.

Its cost me $100 to run it this way for elect charges, plus all my elec usage from being in there, last december 2017. Everytime I go out it was perfect. -14 actual temp was coldest day. Averaging about 18 degrees id guess.

I own a 1000 sq detached shop with hanging gas fan blowing furnace - way dirtier dust wise. There is no filter on that. Wayyyy louder.

Things i will change - switch to gas instant hw boiler. They are pricier initially.

If i was not doing this i would put in a radiant tube heater.

Both above require venting and holes in my bldg.
My elec setup is sealed and i.have no running water in shed.

If you unsure, do the foam, vapor barrier and get the pex in the floor and hang a manifold on the wall. You virtually cant add it later without crazy expense. Even if you need more time later to add a panel.

You dont have to only use one solution either.


Glad its my shop I am responsible for - I only have to make me happy.

Reply
#22
Just wanted to note that some of the replies are talking about overhead radiant tube heaters and not in floor radiant heat systems.

I used to rep and troubleshoot for a radiant tube manufacturer.  In the right application, such as high ceiling facilities, there is nothing better.

If I was going to use radiant in floor heating (for a house or shop) I would use it in conjunction with a forced air unit.

Lonnie
Reply
#23
(01-17-2018, 10:19 AM)crokett™ Wrote: What temperature do they keep the house at and how old/well insulated is the house. My heat pump has no problem maintaining 70 degrees in temps down around 20.  Sure it runs longer than at 40 but that's expected.  I'd keep the thermostat at 65, but I lost that battle long ago.


         House built in 84 and very well insulated in the attic standard in the walls. They keep it around 70. They haven't run the heat pump since yesterday afternoon and the contactor on the em heat died... (bigger one to be installed tomorrow morning)  I had them run the heat pump and the vent temp was ok but not great considering it was 60 in the house. It was in the low 20s when I was there. Was 9 this morning and they stuck a couple space heaters near the return vent.

           3.5 ton unit but it really could go down to a 3 to 2.5 and would do fine in the summer however there is no way I'd do a 2.5 heat pump I'd do straight electric heat which is a cheaper system and they would be happier with it.  They are still used to a gas furnace or straight electric that runs for a short bit then shuts off. They don't like or understand the much longer run times of a heat pump.

         Their neighbor converted to gas as they have it for the hot tub. Overall heating costs are lower and it's much faster. No running fans and compressors for long periods.


         
           As for the radiant heat has anyone done radiant cooling of a floor. My concrete shop floor in my insulated building can easily reach 100* in the summer if the ac hasn't been run intermittently during the summer. 
         Have toyed with the idea of running the well water through floor tubing to cool the slab. (Irrigation water) Or running that water through a radiator and fan to cool the shop whenever the pump runs...
Reply
#24
(01-17-2018, 01:36 PM)BloomingtonMike Wrote: Wish you could come visit my shop and see the actual truth in owning a hydraunic radiant floor heat setup in a shop.

Here are my facts not guesses

7 degrees at 7am this morning outside
Shop was 57 degrees with no lights on
Its 40x64x16 pole barn - my own personal warehouse big I assure you when its just a tool and plywood shop - no planes or semis,  just a scissor lift and tractor with forks as building tools for now
Electric Boiler is set to 109 degrees - 24kw $360 instant hot water heater from amazon deal - has three elements it uses as needed to deliver heat based on inlet temp of water temperature you put into it
~2600' of 1/2" pex in 9 loops in the middle of 2560sqft of 5" concrete  all one zone - pex and manifold was about $1000
2" closed cell extruded poly styrene foam under concrete reused from roofers and 10 mil vapor barrier ~$500
I spent $800 on my.panel parts and awesome pumps and built it myself and its way nicer than the $2700 one I copied pre made. Its a two loop setup and controls delta of temp of water entering boiler by using a mixing valve to dump the small primary loops hot water into the cold water from floor before entering boiler.
Inzulation is most important no matter what you use.
I have 3"-4" closed cell 2lb spray foam on ceiling and gable ends (wish it was everywhere) and r19 batt on walls. $10,500 total between too and that includes install of spray foam

In floor temp probe measuring temp
Thermostat is turning on pumps when floor temp probe spot's temp drops below 62
Room at 5' up on south wall and the spot on one of my tool box on noth wall reports 57 degrees.

I can move two 14'x14' roll up insulated doors up and down and have two little girls running in and out playing in snow and hide and seek for hours and I cant tell the difference in temperature while I am there.

That was a funny joke about the hot floor feet temps or someone should visit a doctor.

Its cost me $100 to run it this way for elect charges, plus all my elec usage from being in there, last december 2017. Everytime I go out it was perfect. -14 actual temp was coldest day. Averaging about 18 degrees id guess.

I own a 1000 sq detached shop with hanging gas fan blowing furnace - way dirtier dust wise. There is no filter on that. Wayyyy louder.

Things i will change - switch to gas instant hw boiler. They are pricier initially.

If i was not doing this i would put in a radiant tube heater.

Both above require venting and holes in my bldg.
My elec setup is sealed and i.have no running water in shed.

If you unsure, do the foam, vapor barrier and get the pex in the floor and hang a manifold on the wall. You virtually cant add it later without crazy expense. Even if you need more time later to add a panel.

You dont have to only use one solution either.

Hey Mike,
We are just discussing a new shop for work.

I am about 40 or so miles North of you.

I would be interested in seeing your shop in the future 
Yes
Greg

It's better to burn out than it is to rust

Danchris Nursery
Reply
#25
"If you unsure, do the foam, vapor barrier and get the pex in the floor and hang a manifold on the wall. You virtually cant add it later without crazy expense. Even if you need more time later to add a panel."
Both my house and woodshop have pex radiant heat in the slabs, I will never pour a slab up here without adding the tubing coils even if I have no near future use for it, its to cheap not to do it.
Reply
#26
BloomingtonMike, where do you set the tstat day/night, and if it is 15F outside and you want to bump the tstat higher by 3F, does it take long?
Reply
#27
I have in-floor radiant heat in my basement slab and the garage.  Man, that slab heat in the garage is the cat's meow.  Yes, I'm spoiled, but I live in a spot where the winters can be bone-chilling cold so I don't feel guilty.  

It runs off a boiler that also provides hot water for the house.  I keep the garage thermostat at 20C (68F) in the winter, and turn it down to the lowest setting 10C (50F) in the summer, so it's essentially off.  When the garage door is opened in the winter, it gets cold for a bit but recovery is pretty decent.

My neighbor has radiant heat in his floor that is run off a dedicated hot water tank.  Cheaper than a boiler, but won't last as long.

I'm a big fan, like it a lot better than forced air.
True power makes no noise - Albert Schweitzer.       It's obvious he was referring to hand tools
Reply
#28
(01-17-2018, 05:13 AM)Robert Adams Wrote: "There might be a unit made for hooking up to a heat pump and getting it to heat water but I have never seen it. "


  There is/was such a thing. We used to install them 25 years ago in order for the people to get a special rebate on a Heat Pump from the Co-Op.  They worked ok for the first 3 or 4 years, then they just became a problem, so we removed them. It used the hot gas refrigerant. Had a pump to cycle the water.



We don't do floor heating here, I studied it for a while in case we ever ran into one. Ran into one one time in all these years. I therefore don't qualify to give much advice on the subject except that it is a slower heat recovery rate.

 To change temps in a shop where the heat will be kept at a low temp when empty, then expected to raise the temps fairly quickly, a heat pump is fine, but it is going to operate the electric strips or gas furnace (auxiliary heat) until the balance point is met.  If the space is going to be occupied all the time and the temps are kept within a limit based on the outdoor temps, then it may work out. On 50 degree days ok, but on 20-30 degree days maybe not so.


 I just did a 30 x 50 metal building shop and we ended up with central elect heat because he wanted to leave it vacant and then warm it up for a while then close it down afterwords. But we don't require that much heat here either except for a few days.

A vented fuel heater doesn't add moisture to the air/space. It's just the temp change that causes the tools to sweat until they warm up. Keeping a constant temp helps prevents this. Warm air holds more moisture than cool air- as the air cools when it hits a cooler cast iron surface, it condensates. Like a glass of iced water.
Reply
#29
I wouldn't even consider another way to heat my shop. Radiant in floor is fantastic, especially in a large space with tall ceilings. It allows you to almost reverse the physics of heat rises. You are able to heat the floor and keep the heat down where you need it. In a tall space it will actually cool off the closer you get to the ceiling.

With the floor warm and your feet warm you will be warm, and you will also find you are able to keep the thermostat set much lower than with other systems. 52 degrees no longer feels cold and drafty, whether your standing at a saw or lying under a vehicle, it's perfectly comfortable. When you open doors or pull a cold vehicle in, the giant mass of warm concrete makes the space quickly recover and feel warm almost immediately. Melting snow or water on the floor dries quickly.

True you can't only run the heat when you want to use the shop, it takes hours to raise the temp a couple degrees and hours for it to cool down that same couple degrees. It works much better to find a comfortable setting and just leave it alone. Keeping the heat down where you use it and the ability to maintain a lower temp setting makes heating the space cost less. The space is always comfortable and does not swing from hot when it's running to cold when it's off. Most of these systems are almost dead silent when they run, you literally have to walk over and look to see if it's running.
Reply
#30
I set it at 60 all the time. If i bump it up 3 degrees it does not take long at all for the floor fluid to raise three degrees but i do not see three degrees in the room as fast but it is not hours. Ill measure it closer.

Its the same temp in there when outside it is at 35,25,15,5,-5. Its freeking awesome.

You want the best? Closed cell spray foam the walls and ceiling too.

Anytime on the shop tour.


Glad its my shop I am responsible for - I only have to make me happy.

Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)

Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.