Does Radiant Floor heat make sense

[Sumboodie]

Like I said, waste oil boilers take a lot of maintenance. Every few hundred hours of run time, perhaps once a month, maybe more often. Every situation is different. Different oils create more ash.

You mention about a 10,000 sqft building. Depending on which manufacturer of PEX tubing you talk to they will say roughly 25 to 30 BTU prt foot of tubing. In my experience, and I have done two car garages and everything up to 35,000 sqft truck shop, you will use very close to one foot of tubing per 1 sqft of floor. so 10,000 sqft x 30 BTU comes out to 300,000 BTU. No sense in putting in any larger boiler than that because that is all the tubing can handle. No if you add a side arm domestic water tank, or some forced air hydronic heaters you might want to add that load to the mix.

Clean 1-2x a season unless you're feeding it some really bad oil.

It's far less time than a wood stove.

My boiler pump runs about 1200hrs a year. The boiler maybe 700-800 hrs.

 

[Mr onetwo]

I will throw this out....suspended infrared tube heaters. If you save money putting 1" under the slab, then these heaters may work for you. I have one in my garage and it works well. I haven't had a problem in 16 years with it.Hot head instead of hot feet . I also used 1" foam under the slab and it is fine.Around here some people are using closed spray foam under the slab. You could check that out price wise.

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[jblnut]

I have radiant in both my house and shop.

It’s ok, but even with an outdoor reset, response is inadequate for days that it’s cool at night, ie the twenties, and warm, ie 60s / 70s during the day. Perhaps controlling off floor rather than air temperature would be better.

You need a floor stat. It’d keep the floor temp where it needs to be day and night and all but eliminate the wild temp swings.

I've had buildings with floor heat and all over run the temp.

30* at night, 60* in the day. Boiler runs all night, satisfies in morning and slab loaded with heat. Add warm outside and sun... it's going to overshoot.

A floor stat will all but solve the over run issues. I have them in all the in floor systems around here and they work amazing. Daytime temps in the 50’s and the floor still calls for heat to keep itself warm. Nighttime temps in the teens, it calls for more heat as it’s radiating out a bit faster. I have the thermostats set to kick on at a certain low air temp as well in but that rarely happens.

I plan to install a hanging natural gas heater for fall and spring when just a quick heat is needed. Also is nice for fast recovery when doors are open and it's -30*

In my house we have a forced air system for upstairs and it keeps the air temp consistent day and night. In the shop it’ll vary from 58-60f no matter the temp outside or time of day. Shop floor is set at 62f usually.

The things you guys are complaining about are preventable and are not blanket in floor radiant heating issues. A floor stat will prevent the over runs if used correctly.

 

[Doubled33]

I will throw this out....suspended infrared tube heaters. If you save money putting 1" under the slab, then these heaters may work for you. I have one in my garage and it works well. I haven't had a problem in 16 years with it.Hot head instead of hot feet . I also used 1" foam under the slab and it is fine.Around here some people are using closed spray foam under the slab. You could check that out price wise.

Infrared Tube Heaters | Building Gas Tube Heaters

Infrared tube heaters from SunStar Heaters brings your building reliable, warm gas tube heaters at an affordable price point.

sunstarheaters.com

I have seen these as well. I cannot get my head wrapped around how they work and if they work well. They just seem Odd to me but worth a look. Thanks!

 

[Doubled33]

You need a floor stat. It’d keep the floor temp where it needs to be day and night and all but eliminate the wild temp swings.


A floor stat will all but solve the over run issues. I have them in all the in floor systems around here and they work amazing. Daytime temps in the 50’s and the floor still calls for heat to keep itself warm. Nighttime temps in the teens, it calls for more heat as it’s radiating out a bit faster. I have the thermostats set to kick on at a certain low air temp as well in but that rarely happens.


In my house we have a forced air system for upstairs and it keeps the air temp consistent day and night. In the shop it’ll vary from 58-60f no matter the temp outside or time of day. Shop floor is set at 62f usually.

The things you guys are complaining about are preventable and are not blanket in floor radiant heating issues. A floor stat will prevent the over runs if used correctly.

Until this thread I did not know there were different T stat types.

From you say above why would anyone want a T stat other than a floor stat? Is there a big pro/con?

 

[finn]

I've had buildings with floor heat and all over run the temp.

30* at night, 60* in the day. Boiler runs all night, satisfies in morning and slab loaded with heat. Add warm outside and sun... it's going to overshoot.

I plan to install a hanging natural gas heater for fall and spring when just a quick heat is needed. Also isnicd for fast recovery when doors are open and it's -30*

That’s what I ended up doing in my shop. Propane boiler with radiant tubes in the floor to maintain a base temperature, then added a hanging heater which I use to bring the shop to working temperature while I’m out there.

i installed a mini split in both the shop and office earlier this month. I’ll experiment using that to bump the temp in the office and bathroom this fall.

 

[Firebrick43]

From you say above why would anyone want a T stat other than a floor stat? Is there a big pro/con?

Buildings with good solar gain (south facing windows) can have issues even with a floor stat on sunny calm days. Probably not an issue but they do make thermostats that measure both slab and air temp. An outdoor reset in conjunction with the floor stat to prevent over runs on those days.

 

[jblnut]

Until this thread I did not know there were different T stat types.

From you say above why would anyone want a T stat other than a floor stat? Is there a big pro/con?

In my farm shop I have the air temp set to 52f and the slab temp set to 63f. When the doors are open for a bit the air temp cools off faster than the slab will radiate heat so to speed up recovery the air temp will trigger the pumps to start and they’ll eventually turn off when both the air temp and slab temps are happy.

Buildings with good solar gain (south facing windows) can have issues even with a floor stat on sunny calm days.

That describes my parents house perfectly. Lots of South windows and the house will heat up on warmer calm days. To solve that we set the floor stat a few degrees cooler and adjusted their forced air system a bit to pick up the slack. Works great now.

Probably not an issue but they do make thermostats that measure both slab and air temp. An outdoor reset in conjunction with the floor stat to prevent over runs on those days.

All the thermostats I have connected to in floor systems work off both slab and air temp. Simple cheap little units but they are not smart at all. No programming of any kind other than set temps. I’ve looked a few times for programmable units so I can put one in the shop to change it day and night. I like to pump heat into the slab during the day when I’m around to fill the outdoor stove and let it cool off a bit at night so it doesn’t hit the stove quite so hard so I don’t have to get up at 4am to fill it when it’s dark and -30f. Sort of like a giant heat battery. It works great but I have to set the temp up each morning and down each evening and sometimes I forget to set it down lol

If you’re doing an outdoor reset that ties into a mixing valve of sorts that can see slab and air temp I’d say that would be the best. It still won’t totally prevent a bit of overrun with lots of south facing windows. No heating system will though so it’s not just an in floor problem. If there is more solar energy coming into the house than there is heat escaping the house will heat up. It seems that if the floor itself is 70f the floor should not be adding much heat to the house when the house goes above 70f air temp.

 

[HoosierBuddy]

I've had buildings with floor heat and all over run the temp.

30* at night, 60* in the day. Boiler runs all night, satisfies in morning and slab loaded with heat. Add warm outside and sun... it's going to overshoot.

I plan to install a hanging natural gas heater for fall and spring when just a quick heat is needed. Also isnicd for fast recovery when doors are open and it's -30*

That's not my experience. What water temp are you running?

 

[Copymutt]

Times 2 on the mix of in floor and hanging Modine for the shop. Neither has been expensive to operate. Zone 7. Each has its strengths. I also incorporated passive solar gain & have to dump heat on some winter days. May switch to floor stat to see if things equalize.

 

[jblnut]

That's not my experience. What water temp are you running?

I know you didn’t ask me but I run 90f water to the floor when pulling heat from the outdoor wood stove and from my condensing IBC LP unit.

 

[PoorUB]

Clean 1-2x a season unless you're feeding it some really bad oil.

It's far less time than a wood stove.

My boiler pump runs about 1200hrs a year. The boiler maybe 700-800 hrs.

We have never had a waste oil boiler run over a month in the winter. Never had one run 800 hours either. Usually about half that. Maybe you feed yours with better oil!

 

[Mr onetwo]

I have seen these as well. I cannot get my head wrapped around how they work and if they work well. They just seem Odd to me but worth a look. Thanks!

They work very well.Back in the days before infloor radiant they were very common in commercial/industrial applications with ceiling height 12' and above.Also very cheap compared to alternatives. Put in a lot of them. Given my druthers, I would put all my money into insulation and air sealing, then tubes in.