Existing structure (mainly weekend use at present) is 2800 square feet entirely open plan with all cathedral ceilings on upper level. Bedrooms and family room on walk-out lower level, half bermed. No basement. Now fairly well insulated and sealed. Vermont Castings (Encore?) stove in brick fireplace on lower level is used extensively, but wish it were bigger; large zero-clearance (Superior?) fireplace on upper level almost never used. Single large heatpump for heat and cooling -- and for circulating warmed air from the VC stove. Endless hardwood on 100 acres.
Now planning a very well-insulated, two-storey, 2000 square foot extension, about a quarter of which would be a garage on the lower level. HVAC via a second heatpump, ideally with propane boiler for radiant slab and floor heat.
If I can afford it, I would love to add a gasification wood boiler to do most of the radiant. Despite its price, I am attracted to the Garn because of its simplicity, the size of the firebox, and integral water storage, but I am open to other suggestions. From what I've been reading here, installation is a very significant part of the total cost, can be complicated, and the availability of the necessary local plumbing expertise could be an issue. DIY is not an option. (I have not yet contacted Garn or anyone else to see if there is such expertise in the area.)
(If I can't afford a boiler, any opinions here on a second wood stove? Large -- to take large pieces of wood and for long burn times -- and efficient.)
I wouldn't want a boiler within the proposed extension's two-storey envelope because, if I were going to use it for DHW (or for heating an eventual pool or hot tub) outside the heating season, I wouldn't want the heat rising and adding to what we already have plenty of in the Virginia summer. I would also like to keep the inevitable messiness of firewood away from the living areas. For that reason, what I'm thinking of is to add a room to the lower level of the extension in the crook of the "L" of that extension's footprint. The insulated boiler room would be on a slab under a high, metal, waterproof deck, under which would also serve for wood storage.
Lots of questions:
-- For radiant heat, is it best to circulate the heated water directly from the boiler through the pex in the floors?
-- Could a heat exchanger for DHW be added to/alongside of such a direct circulation system? If so, any
concrete recommendations?
-- Since the house could easily be unoccupied for significant periods (and we had minus 4 here recently), can the system be made freeze proof by the addition of anti-freeze to the boiler water? Or, can that danger be addressed by including the boiler room in the radiant system with the propane boiler backup?
-- Besides being super insulated, what would the best (and reasonably priced) boiler room look like? Concrete block? Two-by framed? Fire/code issues?
BTW, I am very impressed by the knowledge and generosity of those participating here. The good side of America (and Canada).
Now planning a very well-insulated, two-storey, 2000 square foot extension, about a quarter of which would be a garage on the lower level. HVAC via a second heatpump, ideally with propane boiler for radiant slab and floor heat.
If I can afford it, I would love to add a gasification wood boiler to do most of the radiant. Despite its price, I am attracted to the Garn because of its simplicity, the size of the firebox, and integral water storage, but I am open to other suggestions. From what I've been reading here, installation is a very significant part of the total cost, can be complicated, and the availability of the necessary local plumbing expertise could be an issue. DIY is not an option. (I have not yet contacted Garn or anyone else to see if there is such expertise in the area.)
(If I can't afford a boiler, any opinions here on a second wood stove? Large -- to take large pieces of wood and for long burn times -- and efficient.)
I wouldn't want a boiler within the proposed extension's two-storey envelope because, if I were going to use it for DHW (or for heating an eventual pool or hot tub) outside the heating season, I wouldn't want the heat rising and adding to what we already have plenty of in the Virginia summer. I would also like to keep the inevitable messiness of firewood away from the living areas. For that reason, what I'm thinking of is to add a room to the lower level of the extension in the crook of the "L" of that extension's footprint. The insulated boiler room would be on a slab under a high, metal, waterproof deck, under which would also serve for wood storage.
Lots of questions:
-- For radiant heat, is it best to circulate the heated water directly from the boiler through the pex in the floors?
-- Could a heat exchanger for DHW be added to/alongside of such a direct circulation system? If so, any
concrete recommendations?
-- Since the house could easily be unoccupied for significant periods (and we had minus 4 here recently), can the system be made freeze proof by the addition of anti-freeze to the boiler water? Or, can that danger be addressed by including the boiler room in the radiant system with the propane boiler backup?
-- Besides being super insulated, what would the best (and reasonably priced) boiler room look like? Concrete block? Two-by framed? Fire/code issues?
BTW, I am very impressed by the knowledge and generosity of those participating here. The good side of America (and Canada).
