Radiant/Forced Air Heating Hybrid
Wongliozzimangopony
| Posted in Energy, Heating & Insulation on
I am building a 2500 sq. ft. 2-story over a crawl space, and want to use hydronic heating. The cost do use this on both floors seems insanely expensive. Most of the daily activity will take place on the ground floor, with just bedrooms upstairs. Does anyone have experience with a hybrid system that uses hydronic radiant heat on the ground floor, and forced air on the top for supplementry heat and air exchange? I suspect that we may not need to run the upper-floor furnace much in the mild SF bay area climate.
Replies
Since you might have a boiler in the plans..........
why not think HW baseboard and in floor in the baths.
We have HW in the slab down, open floorplan. Use 1-4 ft. baseboard in the two remote BR's. Hose on top of subfloor and below tile for the two upstairs baths.
Supplement heat with a masonry heater and keeping the gas bills down.
This in NW Ohio.
Hydonic heat downstairs
Wongliozzi,
If you pay attention to your thermal envelope -- that is, if you aim for very low levels of air leakage and install thick insulation -- there's no reason you need any heat upstairs at all. If your first floor is heated, there's no reason for your second floor to be uncomfortable.
Of course, you need to work with a designer and builder who understand whole-house principles and energy-efficient construction practices for this approach to work.
Martin
That is a good thought and it works.
Utilizing proper site orientation to capture and also limit the sun can add comfort at a low operating cost.
An open and convecting floor plan will move the air naturally (or with just a bit of help).
Mass to hold heat and distribute evenly and slowly will also lower operating costs.
We live in a 2400 sf house in NW Oh that had a month max 60.00 gas bill for running the boiler for the radiant (full slab down, in floor in 2 up baths and 4' of HW basebd in each of the remote bedrooms up), burned a little over a cord of wood in the masonry heater, and cool the house with a window AC. A good bit of planning and a lot of luck I guess.
I would not
install a forced air system for the upstairs only. The air handler, the ductwork, and the rest of it takes up room, either in the house where you'll be giving up usable space, or in the garage/basement/attic, which is far from ideal.
Once you have a boiler in the plans, it should be easy enough (and not particularly expensive) to run tubing for the upstairs floor. It sounds like you are installing the downstairs tubing on or under subfloor, so do the same upstairs. This seems far simpler than installing an entire second system.
Or, like Martin says, you could do without it entirely.