Sizing & Selection


More Tools and Next Steps

  1. Click Here to download the above form as an Excel spreadsheet.
  2. Estimate pricing:
  3. Click Here to download an Excel spreadsheet and calculate your annual savings and payback period with GARN® heating equipment


It is important to not undersize or oversize any heating appliance. These tools will only provide a preliminary estimate for sizing your GARN unit. A detailed heat load analysis should be completed before final sizing of any GARN.  The BTUH’s calculated above are for your coldest average month.  Warmer outdoor temperatures mean a smaller effective heating load, so the thermal storage will last longer between burns.  Colder outdoor temperatures have the opposite effect.  Contact your local rep for further assistance.