I have been thinking, and getting advice here, on how to heat a house we’ll build.
The thinking is to use an LP fired mod-con boiler, heat the woodframed main floor with panel radiators (the hot loop), and the lower walkout level (ICF walls, mostly) with infloor radiant.
One Breaktimer suggested that for the lower-temp radiant part, we mix down with a manual mix valve, to achieve the lower temp, and that’s that. Trouble there is that we supply with one temp only, which seems inefficient at moderate temps outside.
We are now thinking we may add sophistication by use of the Taco RMB-1 radiant mixing block for the radiant side, using its outdoor sensor to temper the mix up and down as needs dictate. The two zones of radiant would be controlled by tstats.
Upstairs, the hot radiator loop would be controlled by one tstat, set high, and owner control of the various spaces would be done using the TRVs mounted on each rad.
The whole scheme might look like the diagram attached. Tstats are not shown, nor is the boiler loop.
Comments, please?
Replies
The block is a nice setup, but a lot more money than a mixing valve. You don't need a lot of temp variation for the infloor. Use the mixing valve. Use outdoor reset with the trv and you will get the greatest savings.
Even better, put in oversized rads, and you can lower the supply temps even more.
Remember, lower supply temps = greater fuel savings.
Edited 2/16/2007 12:17 am ET by rich1
Thanks for the advice. I met my local heating pro this early a.m. (this job is outside his territory) and he confirmed your thoughts.
There are two zones of slab radiant. One with glue-on carpeting, the other will have 3/8" gluedown engineered wood. We though two mixing valves, one per zone, each zone mixed for its floor covering.
Having run the heat loss analysis conservatively, and coming up with 53K Btu/h heat loss, and looking at just the part we'll do with the radiators, we've got over 10 percent excess heating capacity there, so we should be in good shape.
So now I am wondering whether to use a Triangle Tube Prestige Solo 110, or a Munchkin T80. The Solo seems like too much boiler. It's not my house, it's a spec, and in heating season, will be used as a weekend ski getaway. The competition is going cheap with Weil McLain WGO oilburners, baseboards, no outdoor reset.
We're sticking an LP-fired direct vent gas fireplace in the greatroom with a blower kit, probably capable of providing almost enough heat for the whole place.