You have existing ductwork? What is your electric rate and area of country you live?

IMO

Only ductwork in the bedroom areas, not the main living area and no way to connect ductwork from furnace to main living area. It is 11 cents per Kwh and I'm in central OR, high desert.

So it does not work well with wall to wall carpet and is many $$$$ to install in a renovation. Have you looked at hot water radiator type heating with a boiler it might work . I have it and love it the heat is even all the time and we have 3 zones you can add as many zones as you need. We like our bedrooms quite cool . I think it is worth taking a look at they can be electric baseboard heat but I find those really affect where furniture can go but the hot water ones are fine with some stuff near them.

I live in California, my local utility company provides the information you are looking for, perhaps your utility provider does too.

@Patricia Colwell Consulting I haven't looked into that, because I didn't really want rads everywhere, but if it is the most cost effective long-term, may make sense. I did see the cost was very high for radiant, but had a 30 year warranty, so thought it might pay for itself comparatively if it worked well. Thanks for the info!

@User Thanks, I will give them a call. I don't see anything online about anything other than heat pump. I did see something about selling solar to them, so I may look into that as I have a large area on my land that I could put solar panels on!

Not sure how it would fit with your budget, but solar for water to heat tile floors plus mini splits to carry the AC load in summer is one option. True, there is an electric system that heats under carpet, but seems electric is too pricey for you to use year round. The best conductor of radiant heat is tile, but a hard surface can be hard on the body, especially if you're older, arthritic, etc. Here's an overview, some of which should apply to your situation.

Thanks @decoenthusiaste. That is interesting, I will definitely learn more about that. I don't have any cooling right now and it was fine, but it would be nice to have in the guest bedrooms.

I think you should talk to a HVAC professional. I was reading about some systems that have motion detection tied to the thermostats. There is an "occupied" temperature and "unoccupied" temperature.

There are two basics that you should know about radiant floor heat. First, it is generally the most expensive way to deliver heat from any fuel in terms of building cost. Second, there is a lot of inertia -- you don't instantly heat up a room and when you turn off the heat or turn down the temp, it cools off slowly. That can be good, but not so much if you use a room to exercise then the family wants to use the same space for lounging on a cold day. It is not so great for big diurnal temperature changes that you typically see in deserts.

It is the best way to heat, especially with high ceilings. Few find it worth the cost if mechanical cooling means ducts plus a second method of moving heat.

I love my hot water heat but it has the same issues with changing room temp it works on heating the mass of the space not the air so a slower warm up and cool down but the eveness of the heat once to temp is awesome and the big bonus no dust blowing around,.

Retrofitting would probably be expensive, but my house is entirely heated with hydronic radiant heating, built into the poured concrete foundation and also installed above the subfloor on the main floor. The loft doesn't have or need any. There is a long enough thermal lag that we don't change the temperature at all! When we started using this as a vacation home, we would set the temperature to 50° when we weren't there. We were living about 6 hours away and, when we left to drive up, we would increase the temperature to 70° (WiFi thermostat). It wouldn't reach the new temperature until the next day!

Patricia, are you writing of radiant floor or other types of radiators or convectors?

mtvhike's, inertial situation is the max with heat exchangers embedded in concrete. Under other types of floors, there is much less inertia, but inertia there is. If you want to get away from that, forced air is optimal

Radiant heat is super efficient if it is water pipes in concrete floors.. the electric pads under flooring not so much...i had these floors in aspen ,colo. with the most comfortable heat i have ever experienced....two story ceilings..lots of picture windows and widely varied seasonal temperatures...no problem and very low utility costs..