I live in the north north east (Canada).

Our house had an oil furnace, we added an air source heat pump. There are periods in the winter where the heat pump can't keep up, but in the months early and late winter it's all we need. The net result is that it has significantly reduced our oil consumption. Add to that fact it's an A/C unit in the summer, and it's wins all the way around.

How is the heat delivered? Forced air? If so no problems with heat pumps, the modern air source can produce heat at very low outside temps and a ground source is excellent in very cold climates (if you have artesian well, or ground loop).

The problem is most oil or gas fired heating systems are forced hot water (or steam) so a heat pump isn’t going to help you unless you want a mini-split in every room.

Even if you have ducting for cooling with AC it likely won’t have enough CFMs for heat in the winter unless it was specifically sized that way (but you likely wouldn’t be still using forced hot water or steam in that case).

Heat Pumps absolutely blow both Fuel Oil and very nearly Propane out of the water in run cost, even when electricity is high.

At 30f - until you exceed 15-15.5 cents per kWh, heat pump is cheaper to run than median oil price.

Propane is no better than oil in terms of cost per BTU (except propane boilers are usually slightly more efficient). Natural Gas (from the street) is significantly cheaper than either oil or propane and particularly if used with a modern condensing boiler.

It’s not that a heat pump isn’t more efficient it’s that if you have forced hot water or steam radiators you are looking at an additional $40K to retrofit forced air ducting to your house. Oh and you still need a solution for domestic hot water, probably you’ll just end up with a resistive heater (or a hybrid/heat pump unit like the Aerotherm but the heat has to come from the room).

I went off median prices from DOE and found oil to come in at 32 cents per 10,000 BTU's propane at 24 cents per 10,000 BTU.

You can look at the State of New Hampshire’s Dept of Energy comparisons here, updated weekly:

https://www.energy.nh.gov/energy-information/nh-fuel-prices

Actually right now #2 heating oil is now somewhat cheaper per MBTU than propane. Also Natural Gas is slightly cheaper than heat pump per MBTU (YMMV on efficiency!)

I’ve never seen propane cheaper than heating oil here!

EDIT: It’s probably worth pointing out that the North East of the US is the largest heating oil market in the world.

ooh, thats a great source - now that I've updated my calculator, your numbers match mine - I went with local prices for propane and DOE prices for propane.

Exceed 15 c/kWh? We were past that loooooong ago in California. Here are PG&E's rates for the Bay Area... https://www.pge.com/assets/pge/docs/account/rate-plans/resid...

The cheapest rate is 38c/kWh, the most expensive is 62c/kWh..

Forced air only? What about mini splits? Many homeowners convert from steam radiators to mini splits.

I have an electric water heater. It’s hybrid, so I run the heat pump mode in warm/humid weather and regular electric mode the rest if the year.

I would not want mini-splits in a house in the north east. it gets cold and you need to heat evenly. Plus you'd need them in every room incl. bathrooms so the pipework would be nuts!

Mini-splits are not uncommon for cooling in the summer, but then again you only need them in the main living areas and bedrooms.

Tons and tons of people have mini splits in the northeast!

You don’t actually need it in every single room. A lot of rooms, you can get away with like radiant floor heating or electric baseboards.

If you didn't have an actual heat source in your bathroom, it'd almost certainly freeze when it's <20F out. I'd also imagine that most of the mini-splits you see around the Boston area are for cooling and probably aren't designed for heating in the winter (most HVAC companies tend to spec the cheapest of the cheap condensers for the outside unless you are specific about heating). I actually have a Trane/Mitsubishi ductless mini split and it struggles when it's cold out (eg 30's) and will use AUX (resistive) heat (it's in a garage and is for cooling in the summer!).

A baseboard heater or something like a cadet heater are more than enough to keep a bathroom warm