Heat Pump

We decided to replace our furnace & A/C this year. The A/C was not cooling the house, due to air velocity issues, the furnace was 20 years old, and I was concerned about it's safety. I called one of the highly-recommended HVAC guys, and his suggestion was a "dual fuel package unit" as there was limited head room in the crawlspace to install a conventional furnace. This is a combined heat pump and gas furnace. For most of the heating season here, a heat pump can meet our heating needs, and of course provide cooled air in the summer. On this unit, the balance point (where the heat pump switches off and the gas furnace supplies the heat) is selectable based on outside temperature, equipment efficiency, and the relative costs of electricity and natural gas.

This unit sits outside the house, and ducts extend through the walls of the house in to the crawl space, connecting with the original ductwork. We hope that this unit will address the air flow issues we experienced previously, and make the house more comfortable.

I have not done a complete cost analysis on this unit, and have not determined a 'payback' time. Since we were not satisfied with our previous heating and A/C setup, and I had concerns about the safety of the furnace, we were looking at a replacement in any case. Our space heating costs are about $700 per year (we lower the heat in the house by about 7 degrees C from 9:30 each evening to 3:30 each weekday afternoon), so even if we reduce our heating costs by 50%, I expect it will take many years to recover the price of this installation.

The installation went (almost) flawlessly today -- one of the formed pieces of duct was improperly fabricated, and a large roll of duct tape was consumed in temporarilly bridging the gap. Red Green would be proud. Hopefully it will remain intact until the replacement arrives. As we disassembled the old furnace, we discovered the reason for its' poor performance. The inside of the A/C evaporator which is well hidden and unreachable, was about 50% covered with what looked like a thin layer of paper-mache. Whatever this was, it considerably reduced the airflow, impacting the heating, and the air conditioning. Lesson: check your heating system regularly!