Fana’s design included two Fujitsu mini-splits, (NES installs Fujitsu and Mitsubishi ASHPs) — one 12,000 BTU single-head unit upstairs in the master bedroom, and one 15,000 BTU single-head system on the first floor. Upstairs there are four rooms and one full bath. The downstairs is an open floor plan with a living area, dining area, kitchen, and half bath. The two units have made the entire home comfortable even when the outdoor temperature bottomed out at -13 degrees in early February. The one concession is that all the room doors should be left open so the heat can flow into each room. In my situation, that is not an issue for me, but for families with privacy-conscious tweens or teens, you might want to incorporate those considerations into the design, and provide them with their own condensing unit. The system I installed is considered a partial home system by MassSave. It is not designed to provide whole home heating and cooling — even though it does. A partial home system is eligible for a MassSave rebate of $1,250 per “ton.” A ton is 12,000 BTU. My system is 2.25 tons.
As a partial home system, I still have a fuel oiler boiler as backup. For whole-home ASHP systems, MassSave offers a $10,000 rebate. To qualify for a whole-home system rebate, the primary heating system might need to be disconnected, or the homeowner might need to attest to not use it except in emergencies. There are also other conditions that must be met for the whole-home rebate, which are outlined on the MassSave website. Feel free, too, to call our offices and speak to Fana.
As I mentioned, I didn’t use the boiler to heat my home this winter, but I did use it to heat water. During a typical winter heating season (October – April), my home would use approximately 600 gallons of fuel oil. This heating season, I have only used 100 gallons — an 80% savings! This was the energy stabilization I was looking for. For example, a year ago, before I had mini-splits installed, from October 2021 through March 2022, I consumed 5.4 MW of electricity and used 630 gallons of fuel oil to power and heat my home, respectively. Combined, that was $3,528 of energy expense. A year later, after installing mini-splits, from October 2022 – March 2023, I used 2.5 MW of electricity and 100 gallons of fuel oil for a combined expense of $1,180. This translates into a 66% savings, or $2,348. Add these savings to the $2,812.50 MassSave rebate and $2,000 ASHP federal tax credit, and my ASHP system will be paid back in less than four years. After that, the system will be putting money back into my savings account.