In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
code man says my DHW tank has to go as a heat source What now?
I am not going to get into the battle about DHW tanks as radiant floor heat sources as I am sure it gets folks all fired up! (though I could rage for hours about this topic)
The "MAN" says it has to go, so I am in the market for some knowledge.
Here are specifics of my system/situation:
I have a 900sq foot slab on grade, passive solar, well insulated single story structure.
The heat loss calculations I have done put me at about 28000 to 32000 btu design loss. (depending on which calculator I punch my specifics into...long form ones not the 5 question ones) But none of these take into account the solar gain.
The pex is on 10-12" centres...sitting a bit low in the concrete I suspect.
Four loops in a single zone. (the house is more open concept cottage than "house").
The current illegal heater is a 40 gallon, 30000 BTU run of the mill mid level DHW tank.
(a bit under powered, but does the job)
It gets well cold here. -22ºF is not all that uncommon.
The current system fires up in the winter on average 2 times in a 24 hr period. Three if we are hitting those super cold days. Mostly at night and early morning and only runs for about 20 minutes before it hits the set point and shuts off. I don't hear from it for another 7-8 hours.
The water in the tank - once it has sort of settled out - leaves the tank at about 100ºF and returns at about 82ºF.
Overall...not knowing much about the hows and why's of this stuff...I have been pretty happy.
BUT...I need a boiler apparently.
So I need some help with a logical choice.
Space is a major problem.
Power is a MAJOR issue. (off grid solar) Currently a single grudfos runs the whole thing. And in the dead of winter I cringe when the pump is going as I know it is eating up the power in the batteries.
I don't want to oversize this thing, but I sure don't want to find I have undersized it.
Okay, let er' rip!
Thanks everyone and anyone for your input as it is getting cold and I need to pull the trigger on this asap.