Operating costs of different types HVAC systems for my house

I’m investigating replacing my central ducted natural gas furnace. I see two possibilities, one is to use an ASHP with my existing ducts and the other is a ASHP mini-split system. I asked for quotes and also the operating “costs” for each so that I can determine approximate life time “costs”. I put “cost” in quotes as I have Solar so I want to know how much additional power my system needs to generate to offset the new loads.

I’ve done some searching and couldn’t find anything that would allow a home owner to compare different types of HVAC systems as to the amount of power they would require to heat/cool a house. Does anyone here have any suggestions?

I suppose it’s a bit early to find such a tool as there’s not much interest yet in creating one.

There are two youtube people that choose to combine multisplit A/A with solar, maybe you’ve seen already, if not have a look.



I’m surprised u think it’s early. When I was installing solar a few years ago tools that allowed you to determine the power output of your proposed system based on your location, panel count, panel orientation and your historical power use was common. With those you could/can estimate your lifetime costs (ROI). Hence I was expecting something similar for HVAC.

I happen to be a.programmer if I created a similar tool for HVAC would anyone else be.interested increasing or using it?

Oh, and txs for the links, I’ll take a look!

I had ducted air gas fired heat in one house in Australia so perhaps I should comment. It used an awful lot of very cheap gas to blow some hot air into a poorly insulated house with single glazed windows and enormous exposed exterior surface area. You are quite right to seek improvements because that used lots of gas for not much heating. It was rented, and I moved on.

Where I live now is mid terraced with cavity wall insulation, extra loft insulation, and a gas combi boiler which I’ve hardly used all summer except for three hours elapsed in four months, mainly on bath days. Unheated is feasible until next month, so what insulation would you need to get a sane indoor temperature unheated? So the minimum cost HVAC is the summer policy of “turn it off, stupid!” which is only sufficient after your insulation is sorted out. I continue adding to mine. For example twinwall clear polycarbonate affixed inside two doors should help with warming in winter as much as 1kW.hour per day when outside is 16C colder than inside. Against my present near-nil heating usage, such small insulation improvements can matter.

Later in the month I’ll start using the single room air-air heat pump (an older model of air source heat pump with no hot water connection; 0.7kW electrical 2kW thermal; single blower to a single room like an air conditioner). That much power is fairly often available within the output of my 2.5kW(peak) of solar photovoltaics. With a CoP of 3 at best and less on cold days, that is of help rather than being a complete solution. As it is standalone wall mounted, installation did not touch the existing gas heating. I just use that less.

Txs for the Info!