A govt web site approximates costs for RFH at $4-$6/sf depending on yada yada yada and not counting the heat source. I’ve seen HVAC contractors use $5 as a crude budget number, so there’s some consistency.
But materials come to only about $1/sf on at least one site I found.
Is all the rest labor and profit? Or is there a more accurate way to breakdown the cost of RFH? What are good numbers for budgetting and what’s the rough breakdown (without getting too personal on your margins and such)? Thanks.
Replies
Ballpark?
Usually, the tubing itself runs about $1 a sqft.
From there, you have to pick your poison...
Gypcrete about $2.50. Second soleplate for gypcrete is minimal.
Manifolds/mixing valve/outdoor reset/thermocouples/control&relay boxes/pumps/Cu plumbing from boiler to manifolds...depends on layout & design.
Foil-faced polyiso...about $0.30 a sqft
Al plates & staples...staples are negligible (figured in the $1 a foot cost of the tubing), Al plates try not to use them, depends on the thermal properties of the room, but typically not required.
Go the Warmboard route? That's about $4 a foot over what a traditional subfloor would run, but it does eliminate a few things required by gypcrete, while requiring a few things gypcrete doesn't. In my locale it's somewhat more expensive than gypcrete, way more expensive than staple-up, though Warmboard has great thermal performance.
Profit? Profit??
Summary? For materials only, a staple-up could be had for about $1.50 a foot. Gypcrete about $4.75, Warmboard about $5.45 (WB cost reduced by omitting traditional subfloor).
Your mileage could vary.
I was trying to keep away from flooring components. Just tube, manifolds, tstats, etc--installed costs of all the stuff beyond the boiler that ya gotta have regardless of the concrete/gyp/warmboard choice.
And speaking of installation systems, ever see this: http://www.pfgindustries.com/ Couldn't find cost data, so I suspect the worst.
Jim: Mongo has some good numbers there. I think where RFH really shines is in slab-on-grade. No gypcrete, no staples, no aluminium fins. No floor space eaten up with registers or baseboards. Just spend two hours tying it down to the 6"x6" #10 WWF, (make a diagram of tubing routes, IMHO), and then pour away. Then $1/foot is reasonable. Plus you save $x/foot for ductwork and registers or baseboards and hydronic piping. Where X is $2 or $3.
Regarding manifolds and thermostats: To compare apples and apples, I'd leave those out. If you have 5 zones of baseboards, you need 5 t-stats and 5 solenoid valves in the manifold, just like in RFH. Compared to forced air, I'd compared it to a RFH system with ONE thermostat and manually adjusted balancing valves. Not that I'd ever install such a system, but forced air is often done like that. I suppose I would throw another $50 or $100 per zone at RFH heating costs because the thermostats need to be smarter in a high mass (slab or gypcrete) system.
David Thomas Overlooking Cook Inlet in Kenai, Alaska
Edited 4/29/2002 3:08:55 PM ET by David Thomas