Thinking to retrofit baseboard heat to floor radiant and try to find best way

darkyputz

Hello everyone.,

I am a proud owner of an 1980 fixer upper and have almost finished the envelope retrofit for getting he house more heat efficient.

Since this thing came with really ugly baseboard heat and I am not a fan of high circulation temperatures, my hope was to retrofit at least my downstairs to radiant floor heat.

It it a concrete slap, so I am aware that I am going to lose some room height due to extra on the floor. But hat should not be the issue here right now.

I want to get a working idea on how I can use my high temp oil burner to heat the radiant water without havig to cycle to often and of course reduce the temp in a senseful manner.

Will i have to introduce an extra storage tank with heat exchanger to draw from via thermal mixing valve or can I have the oil burner heat the cycle directly with mixing valve?

Problem is that the upstairs needs to stay on baseboard cause the house already has a renovation state that I cannot rip upstairs apart anymore.

Thx for any ideas

Oh my location is north jersey or climate zone 6b

delcrossv

Primary/secondary with a mixing valve on the radiant. Like a Danfoss ESBE.

hot_rod

a load calc for the newly upgraded home would be a good first step, room by room

If the boiler turns out to be grossly oversized, it will struggle with a small low temperature zone.

Radiant walls and ceilings are another option. Then you would not deal with the elevation changes

Even add 1/2” throws off stairs, and they should be rebuilt to equal rise

delcrossv

Yeah +1 on radiant ceilings

darkyputz

Hello, never heard of radiant walls. Do they have similar/comparable effect like radiant floor? I can imagine that one would loose the effect of evenly rising heat and now changing it to a circular room air movement.

As with baseboard, is it beneficial to have it along the exteriror walls? Or is the fact that it is radiant countering this typical heating practice?

In terms of load calc...how would one do that? Do u have a good source of info that is worth reading?

hot_rod

heat travel to cold, hot air rises subtle difference.

Think of how energy travels from the sun, at the speed of light. As soon as you step out of a shadow and face the sun you feel the heat energy, yet space is cold

Radiant energy strikes any object in its line of sight

You can get a bit more output from ceiling or walls as you can run a hotter surface

If you can run a windows program www.hydronicpros,com has a free heat lisd demo that I like

Or a basic spreadsheet here

https://www.pprbd.org/File/ByAlias/HeatLossCalcXL

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free Idronics download also

DCContrarian

"Hello, never heard of radiant walls. Do they have similar/comparable effect like radiant floor? I can imagine that one would loose the effect of evenly rising heat and now changing it to a circular room air movement.

As with baseboard, is it beneficial to have it along the exteriror walls? Or is the fact that it is radiant countering this typical heating practice?"

What you have to understand is that construction practices have changed tremendously in the past 100 years when it comes to insulation. A house from 1924 would be considered uninsulated today. A house that in 1980 would have been considered well-insulated, compared to a 1924 house, would be considered barely insulated today.

The less well-insulated a house is, the more important the placement of heat sources is to comfort. A lot of the advice given in the past about the placement of heat sources assumed the house was poorly insulated. In that 1924 house, you had to put the radiators under the windows, otherwise it would be 45 degrees next to the window on a cold day.

Wall heat, and its cousin ceiling heat, can only put out a limited amount of heat, they work best in well-insulated houses where the placement of heat sources isn't so critical. Floor heat works best when the heat loss is about 20 to 40 BTU/hr per square foot of floor, more and you won't be able to keep the space warm on the coldest days and less and you won't feel it.

I would start with this article on how to estimate your heat loss based on your fuel usage:

https://www.greenbuildingadvisor.com/article/replacing-a-furnace-or-boiler

That will at least give you a ballpark feel for what your house is like.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1826975#Comment_1826975

Better than 55 btu per square foot from a ceiling. Run it at 100F.

https://wbiwarm.com/blog/radiant-floor-heating/radiant-ceiling-vs-radiant-floor-heating/

hot_rod

When we did a lot of custom homes we would do radiant walls in large tile showers, especially if they were on outside walls.

Radiant ceilings are a bit lower output than walls because as you surmised there still is some air stratificaltion with radiant. The warm objects in the room cause some air currents.

I experiences this when we did fire sprinkler work and trimmed out heads that were 10- 15' above a radiant floor. It was definitely warmer up against the ceiling.

The output multipliers are in the post above. Walls and ceilings are very close.

With walls, typically 3- 4' up from the floor get you plenty of radiant panel square footage for even high load rooms.