I am going to be building a new home in Kingston Ontario in a year and don't have access to natural gas. So my choices are:
- Ground source heat pump (I have lots of land for a horizontal closed loop)
- Standard air source heat pump
- "HE" air source heat pump such as Mitsubishi ZUBA
I am trying to calculate the per year cost of each system including the upfront cost and the time-value of money over the life of the equipment (I'm an accountant so I can handle the numbers if I understand how they interplay and have the data). There are some other calculators out there such as this Gov't of Canada one, but they don't have a ZUBA-like product included and I would like to make my calculations as specific to my circumstances as possible. As well I always like to see the calculations and understand the assumptions.
I found a methodology for calculating Electric, Propane and GS Heat Pump on geo-exchange.ca - see page 12-13 of this document. I've updated it for the fuel unit costs in my area.
Unfortunately they don't evaluate air source heat pumps (ASHP). I was hoping to use the same method as the GS heat pump but just enter a different Coefficient Of Performance (COP) for the ASHP but I can't find these figures. Can I create them from an HSPF number? I am aware that ASHP have markedly different performance at lower temps. I've obtained some weather data so I can handle different COP numbers at different outside temperature levels.
So I am looking for some assistance in how to determine the annual operating costs of ASHP and "HE" ASHP. Any suggestions?
Also, if anyone has comments on the accuracy of the upfront costs for my area (Ontario), it would be appreciated (excludes ducting, just the "machinery"):
- Electric - $$$$$$$ for electric furnace, electric AC and electric hot water heater. Assumed 17 year life (halfway between 20 years furnace and 15 year AC)
- Propane - $$$$$$& for 95% propane furnace, electric AC, and propane hot water heater. Assumed 17 year life (halfway between 20 years furnace and 15 year AC)
- Ground source heat pump (I have lots of land for a horizontal closed loop) - - $$$$$$ for furnace/AC, horizontal loop install, and hot water heater. $$$$$$$$$$ for equipment replacement in 20 years but using existing underground piping.
- Standard air source heat pump - $$$$$$for furnace/AC and propane hot water heater. Assumed 15 year life
- "HE" air source heat pump such as Mitsubishi ZUBA - - $$$$$$$$for furnace/AC and propane hot water heater. Assumed 15 year life
Once I get something usable on ASHP's I will post to Google docs for others to critique and maybe even use.
Thanks in advance.