Re: In floor radiant heating - can't beat it.
From: Marc Rosenbaum (
Date: Mon, 14 Nov 2005 10:16:08 -0800 (PST)
I don't believe there is good data showing that radiant floor heat saves energy compared to other hydronic distribution systems. In many cases, systems that use the European continuous circulation approach will also use noticeably more electricity than a conventional hydronic baseboard system.

Comfort really comes from a superb building envelope without thermal bridging or air leaks.

Radiant floors properly designed are a good match for solar thermal heat or ground source heat pumps, as they use low temperature water that keeps the efficiency of the solar or GSHP high.

Cheap fintube radiation is not great. Hydronic heat can be distributed with cast iron baseboard, units such as Runtal, or pressed steel radiators such as those made by Myson.

If I were designing a day care center I'd choose warm floors. I'm not opposed to radiant heat, but I like to make buildings that don't really need heat distribution at all, when possible. Put the HVAC budget into the building envelope.

At 12:10 PM 11/14/2005 -0500, Laura Fitch wrote:
I think I have to disagree with Chris on this one. I live with baseboard radiation and am very happy with it. I am sure that I would be happy (possibly happier) with in-floor-radiation as well, but I'd want to see the cost comparisons to make a decision one way or the other.

I'm quite sure that our favorite energy systems consultant, Marc Rosenbaum, disagrees with the general perception that in-floor radiation saves in long term energy usage. I'm copying this note to him, so he can dispute or support that idea himself.


Laura E. Fitch, AIA, LEED
Kraus-Fitch Architects, Inc.
110 Pulpit Hill Rd.
Amherst, MA  01002

lfitch [at]

----- Original Message ----- From: "Chris ScottHanson" <chris [at]>
To: "Cohousing-L" <cohousing-l [at]>
Sent: Monday, November 14, 2005 11:53 AM
Subject: [C-L]_ In floor radiant heating - can't beat it.

In floor radiant heat in a concrete slab is a GREAT way to heat your home, or your common house! It does cost a little more, but it can pay back in most situations, depending on energy costs and usage patterns in your area. Required room air temperatures are lower, lowering heating (and energy) requirements. Comfort is incredible.

Baseboard heaters suck, in my humble opinion - hydronic or otherwise. And I believe that the claimed cost savings is not as great as claimed, either. They look ugly, never fit quite the way they were intended, and always seem to be in the wrong place when you want to place furniture. Check with those folks currently living with baseboard heat to see what they think. (eg: JP Cohousing)

Winslow Cohousing is all radiant concrete (slab on grade) on the main floor and hydronic baseboards upstairs. I helped install the system in 1991 when I took a job with the subcontractor. I assume they are still working well.?! Anyone from WCG able to comment?

In about 1998 I built one unit (#29) at Trillium Hollow (the adaptive reuse of the 1200 sf hexagonal gymnasium) and we installed radiant in floor using light weight concrete over plywood sub floors in a wood frame structure. It worked extremely well. WE LOVED THE CONCRETE AS A FINISHED FLOOR. We had it acid washed 30 days after the pour, and then sealed with 5 coats of gloss sealer. It came out with gorgeous blues and greens and rust colors. We chose no crack control because we wanted it to look natural when it cracked. The result was astonishing, and wonderful, and very easy to keep clean. The heat source sufficient for heating the entire 1500 sf (300 sf loft, if you're counting) was a single domestic hot water heater (in addition to the water heater supplying domestic hot water). We truly hated to leave there. (Only my dying father pulled us away.)

We have a forced air system with a heat pump where we are now, and we don't like it. Primarily because of the dust and noise.

Next house we build for ourselves will definitely be in floor radiant heat, with finished concrete floors on the main floor. And the bathroom loops will be spaced at 6 or 8 inches and will run on their own thermostats, and will provide ALL the heat for the house in the shoulder seasons, keeping towels dry and your feet warm when you walk into the bathroom in the middle of the night.

Can't beat it.

Cohousing-L mailing list -- Unsubscribe, archives and other info at:


Marc Rosenbaum, P.E.
PO Box 194 (mailing)
172 Bean Road (shipping)
Meriden, NH 03770

marc [at]

Results generated by Tiger Technologies Web hosting using MHonArc.