Location is everything. Are you in an environment where you need a lot of heat? What are your gas and electric rates? If heating is important and electricity is expensive, you should go gas. If electricity is cheap and you are in a hot environment, mini splits might be a better deal. Either way you go, the ducts should be inside the house, not in an attic or crawlspace.

Can either system make DHW for you?

Here is a link that might be useful: See this and other articles at Building Science

Thanks for the reply. That link was helpful.

The house is in southern CT - so it gets both cold and hot. Stuck in the middle!

Are there any features of a house that would lend itself more towards one system or the other? - too many rooms, etc.?

Reviews of the mini splits have been mostly good, but I have heard some stories of $1,500/mo elec bills! (could have been a leaky house).

What is DHW?

Is this new heating system for the whole house or the addition? If the latter, what do you have in the original part of the house? I'd think in CT, I'd want gas heat because gas is very inexpensive right now.

Ideally, you'd have where the ducts go inside the envelope before you started framing, but it is not too late. Please keep them inside. A little extra planning and trouble will yield benefits for years to come.

DHW is domestic hot water. Your summer time space cooling can be making hot water for you. That is an investment in equipment, however, so you need to calculate the return on your investment.

As I understand it, CT gets really cold.

We have ductless AND ducted minisplits in our house (2 systems). But, we are in the PNW. When it gets "really cold here" (say, 19* overnight), our minis have some trouble keeping up. If you choose electric minisplit in CT, you MUST have an alternate heat source. Do you have a wood stove? Gas stove?

I'd say, with my experience and my understanding of NE winters (and not having ever been to the NE), I'd go with the gas furnace in your circumstance.

One more consideration--cooling.

Does your furnace system include provisions for A/C? Would A/C be desireable/necessary where you live? The minisplits do both--heat or cool--depending on season.

The gas furnace doesn't, obviously.. So, if you go gas furnace route, you'll be able to stay warm enough in the winter, but may always be too hot in the summer without an additional cooling system.

I guess, either way, you are looking at a second system. Which second system is better for you? (accessory heat with minisplits, or accessory air with furnace?)

"Have quotes from one Mistubishi Diamond certified contractor for DUCTED mini splits - around $44,000. But another Diamond cert contractor said he wouldn't recommend mini splits as we have too many rooms, so he quoted $50k Natural gas system."

I'm confused, too. I hope you meant $5,000 for the natural gas system? (You said $50,000).

???????????

50k would be a normal quote if they are having to install a whole house ducting. This isn't just a furnace replacement--*that* would be more like 5k.

"50k would be a normal quote if they are having to install a whole house ducting. This isn't just a furnace replacement--*that* would be more like 5k."

Would have to be an incredibly complicated situation to justify $45,000 in ductwork! The addition is framed but not drywalled. Can't imagine why the costs are coming in that high.

The OP should get more estimates.

(Well, they were that high in my area too...with multiple quotes).

Holy cow! I know prices are regional, so I guess the only solution is to move!

;)