DUCTLESS INVERTER HEAT PUMP TAKES BIG BITE OUT OF WINTER HEATING COSTS
By Mike Hamlin
It is no secret that this has been a much colder winter than normal. January, February and March HHD’S (heating degree days) were on average 16% colder than 2012-13 with March topping 24% colder than normal. In spite of this, our Mitsubishi Super Inverter HP worked flawlessly reducing heating propane usage from 845 gallons to 289 gallons while adding 5002 kilowatt-hours (kWh) but resulting in reducing heating costs from $2,994.00 to $1,705.00, saving $1,289.00. In addition, we saved 606 kWh or $ 100 in reduced furnace blower costs, so total heat savings is $1,389.00 or 46%. Cooling savings on the other hand were $116 for June, July, August and September 2013 vs. 2012. March 31 YTD Total savings in 10 months are at $1,505.00 for a system that has an average installation cost of $3,950.00 (38 % return on investment).
Our home is not a good an example of the ideal energy efficient home, but serves as a great example of what can be achieved with the addition of an 18,000 BTU Mitsubishi Super Inverter H2i ductless heat pump. We purchased the home in 2006 for a chance to live next to the lake after living in California for many years. Other than location, there was absolutely nothing else attractive about it, as it has consumed eight years of my spare time and money in upgrades and renovations. Currently the home uses approximately 70,000,000 (70MMBTU ) annually for heating, which is more than double what I’d expect for a new tight energy-efficient home. However, we continue working on improvements in this area with plans for spray foaming rim joists in the basement and crawl space, duct sealing and insulation, and adding insulation board and bead board to the vaulted ceiling above our dining – living area.
We installed the heat pump in late May 2013. It covers 70% of total heated area which includes a kitchen, dining room, sunken living room, bath and a bedroom. We run it to below 0, but the thermal balance point comes out to be at 18 degrees outside air temperature. From that point we supplement it as needed with the furnace. If our home were at ideal efficiency, the balance point would be at around 0. Our primary heating system is a ducted 96.6 %-efficient 40MBTU propane furnace and was installed in 2003. The heat pump replaces a 24MBTU 10SEER central air conditioning unit. Our electric costs are high at 16.7 cents per kWh and propane prices began in July at $2.86 per gallon and increased at each of six monthly deliveries to a high of $3.80 per gallon with a winter average of $3.52 per gallon.
We are very pleased with both the comfort and savings our new heat pump delivers, and are ahead already with $1,500.00 we can apply to additional energy upgrades. Not included above is the PSNH cash incentive of $900.
State incentives or rebates are available for heat pumps: See NH SAVES at nhsaves.com for participating utilities.
Mike Hamlin is a recognized expert on HVAC working in the field for over 40 years. He has designed and overseen hundreds of installations with heat pumps in many configurations. Mike works for Seely Heating, Plumbing, and Air Conditioning in Meredith, NH. Feel free to email him with any questions: Mike Hamlin <email@example.com>