Liese: One way to define sufficienctly is to use the European standard for "passivhaus" which is generally 80% or lower consumption than U.S.
But another is simply how much you are going to use the radiant system. If you have longer than a three week period where the radiant system will run every day, then you need two tankless heaters. If your other systems mean your radiant system will only be used occasionally, except for a really short period, than you can get by with one. At any rate there is no reason to get a tank system. If you are going to get a second tank eventually for a second bathroom that is not there yet, you might get by with one tank for the moment and adding a second later. In terms of compatibility of tanks with passive solar homes there are ways this can work. It works routine in "passivhaus" designs in Germany, but these are heavily insulated, R40 or better walls, R7 or better windows, R60 or attics, R30 or better floors (below the thermal mass of the floor in your case). Also complete avoidance of thermal bridges, well sealed homes with once through ventilation via a heat exchanger. You have to avoid indoor air pollution for this to work which would mean any wood stove would have to be external combustion. (air intake and outake for stove both being the ouside.)
For homes not built on this principle there are still probably ways around it. For example to deal with the problem of "wasted" stove heat, simply make sure you have enough thermal mass to deal with both the solar gain, and gain from the radiant heating. So extra heat lets you simply turn on the radiant heater later at night. (You have the pluses and minuses of having increased your thermal lag.) Also put the radiant heat in the ceiling instead of the floor. That does not eliminate the problem, but it reduces it. A lot if this depends on the specifics of your house. Do you have an engineer you are working with? I'm taking off now, but my profile addy is good. Email me if you want to discuss this more, and I'll reply later.
Arizona still doesn't switch?
Right. Because of the cows.
Commercial frosting is made with plain vegetable shortening, and Crisco now sells a non-hydrogenated version. Vegetable shortening is the only way to get a pure white icing for a wedding cake.
Oh, and bulging Buffista groupmind, what's the opposite side of the spine in a book?
Fore edge. I only know that because of the wonders of fore-edge painting [link]
Tankless water heaters are much better than they were, and one would probably be okay for just two of you, particularly with low-flow faucets. The problem with tankless water heaters is the water is heated as it goes through the heating element, so the faster the water flow, the cooler the water. They are significantly more expensive than traditional water heaters. You might want to look into point-of-use tankless water heaters, which just heat the water for a single area. They're sometimes used for bathrooms in additions or at the far end of the run from the water heater. It's possible that with your setup, you might be able to use a traditional water heater as part of your thermal mass.
Actually I just googled and now google says it's because it wouldn't be cool enough to have an extended evening. I thought it was because in the 1960s farmers said the cows would get up no matter what clock time it was.
The funny thing google gave me was the subhed for an NPR story that roughly went, "how does Arizona DEAL?!" Well, how does the rest of the country deal with resetting their clocks twice a year? It's not a huge deal to be in a different time zone from other states half the year.
Right. Because of the cows.
And their watches?
Indiana bitched about DST because of the cows. Arizona, however, has a legitimate complaint, IMO. The idea is to increase the amount of daylight that people use. Only, when you increase daylight when you're in the desert, you just get more heat.
I have to confess to finding the whole DST thing a little odd anyway.
I have to confess to finding the whole DST thing a little odd anyway.
I always get a little weirded out by the fact that time is such an artificial construct that we can play with it the way we do with DST. If everyone on the planet agrees (or at least most of them) we just impose a new time on people. It's very strange.
Thanks, Ginger! Damn, those fore-edge paintings are amazing, particularly the videos!
Only, when you increase daylight when you're in the desert, you just get more heat.
Well, you just move around the times you deal with the heat, really.
