Radiant floor heating, "water to water"?

[joea]

Been mulling over adding radiant floor heat under the baths and kitchen floors, ball ceramic tiled.

The heating of the hot water is the big question.

Was thinking of:

- Adding an additional on demand propane water heater dedicated to the task
- using the existing, idle, indirect h/w tank, on one the oil burner loops. (oil is not used currently as have mostly mini splits now.
- Adding a loop to the existing Tagaki TK-3 (domestic h/w) and "reverse plumbing" the indirect heater to run heated water via the potable tank side, to heat the water in the designed for heating loop and running that through the radiant coils.

All with appropriate valving, recirc pumps, expansion tanks, temp controls, of course.

Which is the least stupid? The most ingenious?

 

[FrancSevin]

In my book, electric is the most carefree and efficient method of floor heating.
No Leaks
No pumps, nothing mechanical to fail.
Much easier to install.

Electric Floor Heating | Radiant Floor Heating | WarmlyYours

Our radiant floor heating systems can be used to warm nearly any flooring type from tile to hardwood or even carpet. Shop our electric underfloor heating systems!

www.warmlyyours.com

 

[joea]

In my book, electric is the most carefree and efficient method of floor heating.
No Leaks
No pumps, nothing mechanical to fail.
Much easier to install.

Electric Floor Heating | Radiant Floor Heating | WarmlyYours

Our radiant floor heating systems can be used to warm nearly any flooring type from tile to hardwood or even carpet. Shop our electric underfloor heating systems!

www.warmlyyours.com

The flooring is already installed.

 

[chowderman]

if the flooring is installed, adding "radiant floor heat under the baths and kitchen floors" is going to involve demolition.
you can't add it underneath the subflooring . . .

 

[FrancSevin]

The flooring is already installed.

That would make is less easy to install.

If you water pipe system is presently installed then Chowderman is right. If not, an alternative is Infared fixtures in the ceiling.

 

[joea]

if the flooring is installed, adding "radiant floor heat under the baths and kitchen floors" is going to involve demolition.
you can't add it underneath the subflooring . . .

Pretty sure I know people that have done under floor radiant. Staple up the PEX and formed aluminum reflectors/heat spreaders. Install insulation over that. Heat will move toward cold, every time.

Yep pretty sure I have heard of that happening. And never stayed at a Holiday in Express either.

 

[pixie]

I just changed a whole house from hot air heat to underfloor radiant. Yes, it took some work. Yes, it works great and is economical to run. I used both direct contact 'staple up' with some aluminum plates and tubing spaced 1/4" below floor. They heat equally well.
I had to rip down the sheetrock on the garage ceiling to do it but that was no big loss as ripping out the ductwork had left some big holes. The other end of the basement had no ceiling to start but one area had nails sticking down that had to be cut off.

I would use your idle oil heater system. Propane is very expensive here. You wouldn't use enough to get a volume discount. I don't know what a 'Takagi' is . The oil burner is likely to last longer with less cleaning than any gas fired unit.

 

[pixie]

AND ! Because I couldn't put the pex into an existing concrete floor in the basement, I put it in the walls and ceiling in several places. That also works very well.

 

[joea]

AND ! Because I couldn't put the pex into an existing concrete floor in the basement, I put it in the walls and ceiling in several places. That also works very well.

Takagi is a brand of "on demand" domestic hot water heater. Already installed to provide domestic hot water. Works great, no "cleaning" required at all. I went to that as I got fed up with having to run the oil burner in summer time, making that area of the basement uncomfortable. And oil was skyrocketing then.

I like the idea of adding some "wall" radiant in the basement, some form of home built "panels". Except in Summer, it is pretty cool down there and keeps me from more "projects"

But my admittedly limited experience tells me that oil fired need way more cleaning than does gas fired.

 

[pixie]

From what I read when deciding about boilers, on demand water heaters don't last as long as regular tank type. Hard water compounds the problems. Most manufactures of on demand wanted the device to be cleaned once a year.

I just put some 1" stiff insulation panels in the wall ( the kind with foil on one side) and some 3/4" boards over that ( crosswise) that would allow the pex to go back and forth and sheetrock over that. Ceiling already had 3/4 strapping so that made the pex runs easy but I put the same reflective insulation above those areas.

I may pay down the road but I haven't had my oil boiler in another house cleaned in 10 years. Since the water system is sealed, there is no introduction of O2 and the boiler heats that radiant system just fine. That system is over 20 years old with the tubing about 1/2" under the floor upstairs and a 6" heated slab downstairs.

Using your on demand heater will cut down on available domestic hot water. If you really want to go that way, a seperate one that sent water to the indirect tank would be more efficient.

 

[joea]

From what I read when deciding about boilers, on demand water heaters don't last as long as regular tank type. Hard water compounds the problems. Most manufactures of on demand wanted the device to be cleaned once a year.

I just put some 1" stiff insulation panels in the wall ( the kind with foil on one side) and some 3/4" boards over that ( crosswise) that would allow the pex to go back and forth and sheetrock over that. Ceiling already had 3/4 strapping so that made the pex runs easy but I put the same reflective insulation above those areas.

I may pay down the road but I haven't had my oil boiler in another house cleaned in 10 years. Since the water system is sealed, there is no introduction of O2 and the boiler heats that radiant system just fine. That system is over 20 years old with the tubing about 1/2" under the floor upstairs and a 6" heated slab downstairs.

Using your on demand heater will cut down on available domestic hot water. If you really want to go that way, a seperate one that sent water to the indirect tank would be more efficient.

I see. Different "cleaning". I was thinking "burner" and flue pipe maintenance. I've never "cleaned" a hot water boiler "water side". Never read of a need to do that. As you say, closed system. Without makeup water needed (leaks), O^2 will be gone pretty quickly.
Have to look over the Takagi specs again but do not recall anything about having to clean the potable water side. Or any cleaning other than keeping any vents clear. But I have seen inlet side "add ons" for hard water so, maybe.