Thread by @MassMcPhee

Can heat pumps be the sole source of heating in a cold climate like Massachusetts? Are whole-home heat pumps ready to scale? 2 years, and 168 projects later, @MassCEC reports back.

A THREAD

@MassCEC Executive Summary: yes, whole-home air-source heat is ready for prime time. The technology is there, the demand is there, and the workforce is ~getting there.

Building off @cleanenergymeg's blog:

https://twitter.com/cleanenergymeg/status/1438246637462245377?s=20

. @MassCEC launched our Whole-Home pilot May 2019. We engaged 168 homes, provided a ~modest flat rebate ($2,500) and some technical support.

All homes had gas heat or NC and chose to transition to 100% air-source heat

Why do whole-home when you could do hybrid heat pump/fossil fuel heating? A few darn good reasons:

1)Customers want whole-home heat pumps. It is a more streamlined heating system, no complicated interfaces with legacy systems, and they eliminate fossil fuel usage. Also, no need for duplicative distribution systems to take up space in house.

2)No need to maintain fossil fuel systems. Boiler tune-ups are ~$300/yr plus any system repairs. There’s an extra cost to maintain 2+ heating systems. Not the case with whole-home heat pumps. 1 system for all heating and cooling needs. Simple.

3)No need to invest in another fossil fuel system. With a hybrid system, there comes a day when the legacy system needs to be replaced. This tends to be in the middle of the night on a weekend in the winter for some reason.

When this happens in a hybrid system, few people have a plan to expand their system to a whole-home heat pump. People usually pay thousands of dollars for a new fossil fuel system as they don’t have another immediate choice.

Now you’ve had to pay to replace your secondary heating system. Extra costs there too. A lot of extra costs…

4)Carbon savings. In New England, there are very limited hours when a good heat pump system has slightly higher emissions than a gas system. And, over the ~15 year life span of a system installed today, they get smaller as our electricity gets cleaner.

And with whole-home, you guarantee households are using heat pumps vs. fossil fuel and for all of the square footage.

We investigated satisfaction: 95% of participants were fully or somewhat satisfied with heating performance, and 100% were satisfied with cooling performance.

We investigated costs: median project costs by project type ranged from $12,700 to $20,000. Not cheap, but keep in mind that this is for a heating & cooling system, and that ductless systems also include distribution costs.

How do you compare these costs? To compare to hybrid system, it’s important to include the lifecycle cost of maintaining and replacing an additional fossil fuel system.

To compare to standard fossil heating/cooling: what are the costs of a furnace/boiler, an air-conditioner, and related air-handlers and distribution modifications?

These costs are not that far off from whole-home heat pumps, especially when incentives are included.

Addition of cooling: in the northeast, many homes still don’t have central cooling. Heat pumps (especially ductless) may offer the lowest cost option for adding cooling to an existing home. That is the perfect time to move to a whole-home heat pump.

Workforce: There are companies ambitiously doing whole-home heat pumps, but many are not yet. Whole-home projects ARE more complicated and require more design and sizing rigor. But this is solvable with training, tools, and increased experience.

Complementary Actions: air-sealing and insulation improvements reduce the cost to heat AND reduce the upfront equipment cost. It’s a no-brainer. And any upgraded electrical service will support a charger for your future electrical vehicle.

Conclusions: Whole-home heat pumps are ready, today. There is strong market demand, though awareness among residents and contractors needs to be increased. There is a continued need to expand and enhance this workforce to scale whole-home heat pumps.

But whole-home electrification is ready to become the backbone of building decarbonization, especially as MA pursues aggressive electrification through this decade (1M households out of 2.5M!) (mass.gov/doc/2030-inter…)

CCing: @cleanenergymeg, @kevinkircher, @ASchuur, @panamaredhat, @spantano, @RockyMtnInst, @energysmartohio, @janrosenow, @asahopkins, @JohnSemmelhack, @JesseJenkins

And to be clear: @cleanenergymeg is the heart and brain of this program.