Heard back from Radiantec

I got a call from Don Vance of Radiantec. It's been a couple of weeks since I asked them for a quote. They seem like very reasonable folks. They design a system, then ship a kit that you can install yourself or hire a plumber to install, and they have a lot of detailed information on their website. Their prices seem lower than difficult folks like NW Mechanical.

Don asked for a current plan, so I whipped one up for him:

He suggested continuing the underfloor "staple up" piping under the Trees Room. When the heat has to pass through the wood floor, it means that coming into a cold house and cranking the heat takes longer to have an effect. However, if there is a problem, fixing anything requires ripping up the finish floor. Weighing both, and knowing we have 1230 SF of underfloor, he said, do underfloor. This is also based on Seattle being Zone 4, just a little colder than California, vs. Don's native Vermont, Zone 6, where it gets much colder.

For the slabs, though, he suggested a product called SunFoam that provides insulation against the cold concrete, a floating floor for finishes, and built-in hydronic heating.