Heating a remodeled space
I am currently in the midst of remodeling a space in an older home. It is a Craftsman's Cottage and I am renovating the second floor, (it was previously a large open attic space). I am putting in a master bedroom, bathroom and walk-in closet. Total floor space will be approximately 600 sq. ft. The majority of the ceiling is sloped but the highest point will be 10 feet. Insulation will be a spray-in icynene foam. The bath and closet constitute about 150 sq. ft. of the total floor space. I am having some issues as to heating this space. The original plan was to use a Rinnai gas unit in the bedroom and electric in the bath, but the cost of piping the gas unit has become an issue, (around $2000 just for the piping). I am looking for ideas on alternative heating methods. Any ideas would be helpful. I can't pull off the existing heating system as it will not handle the load, (it's a forced hot air system).
Re: Heating a remodeled space
You would have to check the output of the furnace & do a heat loss calculation of the upstairs apt. to see if there is adequate capacity in the furnace---sometimes the gas burners can be expanded to effect more heating capacity---you could then extend the duct supply & returns to accomodate the new addition.
Generally, the 600 sq.ft. is multiplied by 40 to get a rough idea of the heat load needed---thus 600 X 40 = 24,000 btu/hr.
If you do this for the entire sq.ft. of the house's heated spaced & check the furnace output on its nametag, you can compare the numbers & determine if you have enough capacity for the 2nd floor addition.
Also Google "heat loss calculation" to get more precise HLC calculators.