Without having an energy analysis performed on your home to determine the amount of heat gain and heat loss it is impossible to answer your question accurately.
To help you understand the complexity of your question, below is a list of factors which must be taken into account to properly size and specify a system.
- Amount of glazing and its orientation.
- Amount of door openings and their orientation.
- U value of glazing.
- Material of doors and R value.
- Square footage of ceiling below attic.
- Square footage of wall below grade and R value of basement insulation.
- Square footage of outside wall and its orientation.
- Type of wall insulation and R value.
- Local energy supplier and cost of utility.
I would highly recommend that you find a local energy analyst to assess your home and present to you a series of options. These options should include:
- initial installation cost,
- operation cost,
- maintenance cost and
- duration of time to achieve the return on investment.
Harold Remlinger, AIA Principal Architect DesignTeam Plus, LLC
For more information:
Check GreenHomeGuide's Find a Pro directory to find a local energy auditor.