Is it possible to replace a furnace with a heat pump in an old house?

The duct size for the first floor will not need to change, but when heating, the pass-through vents will work poorly, since the air from a heat pump is much cooler and will not rise through them in sufficient quantity. They will not work at all for the A/C.

Also, you would have to size the pump for a single story house, since you would not be able to heat or cool the second floor without more ductwork. Then, you would have to install a second system for the second floor with all the associated duct work.. This would be quite expensive, but a good choice if you have the money.

A second option is to install a two stage furnace of high efficiency and sized to heat the entire house. At that time have a coil and casing installed for an A/C unit sized for the whole house. Use window a/c's for the second floor. When you have the money for the condensing unit and additional ductwork from the furnace to the second floor, you can have central HVAC for the whole house. .

If you do not have sufficient electrical service for a heat pump with electric back up, you can get a dual fuel heat pump that will have a gas or oil backup heat. It will cost more.

A heatpump works like this: Suppose your furnace quit working in the winter, and you had a window air conditioner. You know that when your AC is running, it pushes hot air outside. So, you turn your AC around and put it in the window backwards, with the controls outdoors. You fish the wire in the window and plug it in, then go outside and turn the AC to max cold. Now you go inside, and enjoy the heat coming out of the back of the machine. This is a heat pump. When you run a heat pump, you're air conditioning the outdoors. Even on very cold days, there's a lot of heat in the outdoor air -- absolute zero is about - 473F. It's cheaper to "pump" heat than to create it by burning fuel, that's why the heat pump is efficient as compared to old fashioned resistance electric heat. Still not as thrifty as gas or oil heat, though.

The disadvantage of heat pump is that it doesn't feel warm -- a gas or oil furnace puts out about 100 degree heat, so when you stand in front of the grill, it feels warm. The heat pump puts out about 80 degree heat, so it feels like you're standing in a cold draft (body temp is higher than the heat pump output). Heat pump is clean, though, and safe, and quite thrifty. You can probably use all the existing ducts, but you need a licensed HVAC person to examine and evaluate, and you will need added ducts or plena (plemums) for upstairs. Please get at least 2 bids, check with builder's association for membership, check with BBB, ask for references, etc.

I guess yes you can replace your furnace with heat pump. To know exact solution of your problem contact Heat Pumps Brisbane.. They will check your house and will provide you proper information whether you can use heat pump or not, which heat pumps are best suitable to your home etc...

You can replace your furnace with a heat pump. I did in a house I owned. Be aware that a heat pump is electric. If your existing furnace is gas you may have to have some electrical work done, perhaps upgrade to a 200 amp panel to handle the load.