More rapid fire questions from someone who is an engineer, has a lots of experience in energy conservation in homes, and is one of the first to get certified as a Zero Carbon (R) coach

Q1: The price of elec makes it uneconomical to go heat pump w/o solar. 

A1. Yes but it is very economical with solar and most houses can generate electricity at 5-10c/kWh (even with some shade on the roof). With a COP of 2.5 (the average in NE for ducted and ductless combined, my Bosch ducted system is about 3.0) the breakeven electricity price at which solar is cheaper than heating with natural gas (not an option in Sherborn) is 12.5c/kWh so most people can save money with a heat pump and solar even if they are on natural gas. With heating oil the breakeven at COP 2.5 is 20c/kWh which almost any roof can do. If your roof is in total shade or is slate or you think solar is ugly then you can buy 100% solar electricity made in MA for about 20c/kWh. This means that using a heat pump can cut your carbon footprint to zero at same cost as heating with heating oil. This won’t save you any money but it will cut your carbon footprint to zero and you will not have solar panels on your roof.

Q2. Despite what was discussed last night if the client thinks solar is ugly…it’s ugly. 

A2. Yes.. See above.

Q3. Geothermal is not feasible forcing the client to continue maintaining the existing system. 

A3. Agreed, geothermal rarely makes financial sense unless you can get the wells drilled for cheap. I am currently investigating if this is feasible on an existing well on our rental property in Dover. I will keep you posted.

Q4. Many ducted AC systems are in the attic outside the envelope. 

A4. Yes but if the sloped sides of the roof are insulated you have brought it inside. Fiberglass is dirt cheap and you can install it yourself or get an installer which MassSave may pay for.

Q5. Window incentives are only available when replacing single pane. 

A5. Yes. This is why I only recommend adding triple-glazed windows when the existing windows fail. Then the incremental cost of the new triple glazed over the cost of new double glazed usually pays for itself in a few years. This is how we did it on our house and clients of mine have done it this way too and they are very happy with the results. Not just lower bills and carbon footprint but fewer cold spots in the house.

Q6. Based on my experience and our discussions a Mass/Save audit is iffy at best.

A6. I agree I have had several done and some were next to useless. That is a government program and suffers from those usual ills. I use it only as a gateway to get the 0% heat loan. This is one of the reasons I think coaches can be so powerful, there is a real shortage of high-quality independent advice.

Q7. It is not possible to power a boiler with a heat pump unless the house is 100% radiant. 

A7. I am genuinely not sure about this. I have not done it myself so I have no direct experience. Manufacturers claim it can be done, but I am wary of their claims. I am about to install an ASHP to power a radiant system. However, I do not see having an existing forced hot water system as a big obstacle. Heat pumps do not replace boilers and radiators. They replaced AC units. At least that is my approach. I have never recommended to a client to take out their existing heating system, forced hot air or forced hot water. If the house has ductwork for AC already then that can be reused for heating. I always recommend leaving the boiler and radiators in place anyway as a back up for when the heat pumps can’t keep the house warm on their own (which is about 20 days a year on our house and our rental house). I am going to be replacing ancient AC units with heat pumps at the rental property and am going to get quotes for using both the radiators and the ducts for distribution. So watch this space! If the house does not have ductwork for AC then it can sometimes be added at reasonable cost from the basement to the first floor and from the attic to the top floor. If none of that works then mini-splits can make sense. We added mini-splits to the other rental house and they work fine for both heating and cooling, though they were about twice the cost of the ducted system at our home.