zlacker

>>PaulHo+(OP)
I've been keeping an eye on heat pump water heaters for awhile, but right now they mostly make sense in warm climates. The big problem is they're still specialty products and marked up like crazy, but also they tend to use cheap components which makes them loud and prone to failure. If you run A/C for the majority of the year then they pay themselves back reasonably quick, barring early failure, but in colder climates they make your house work that much harder to keep the space warm.

The most optimistic hope is that the government mandate will force enough demand that manufacturers can enjoy some economies of scale and actually try to compete on price. I don't think this will happen anytime soon.

>>jandre+Cr3
You're about 20 years behind.

My heat pump is working great at 0F. It's 7 years old.

>>gwbas1+KE3
It really depends on how well your home is insulated. Heat pumps don’t work well on old, poorly insulated houses in cold climates. If they can keep up, which is a big if, the price of electricity generally dwarfs natural gas, even if the heat pump is running at 250-300% efficiency.

>>hippo2+sY4
It's not really correct to say that heat pumps don't work well on old, poorly insulated houses in cold climates. That it's a heat pump is not the issue, that it's cold is not the issue, the problem is only that with poor or no insulation in a cold climate you'll need a huge heater (say, 10-15kW just for the living room). And domestic heat pumps are not designed for that range. If you could get one that big then it would work very well indeed.

If you have a poorly insulated house then the fix is to insulate it, which is what a lot of people are doing around here, with very hold houses. My house is less than 60 years old and very well insulated for the time, and it holds up even today - it's always warm, with the heat pump not even close to its max power.

>>Tor3+585
The issue with “just” insulating your home is that many homes weren’t designed with insulation in mind and thus it’s not a straightforward proposition.

For instance, masonry was a common building material and that is not easy to insulate. You need to add many inches of insulation on either the outside or the inside, both of which have complications.

Even in a basic stick framed house, you’re still talking about taking down all the exterior walls, likely involving removing plaster and replacing it with drywall. Plaster has a number of nice properties, so it’s sad to remove. And that’s not to mention the price of this work.

Finally, roofs need special consideration. Most roofs today need to be properly vented, which was not as much of a consideration when the houses naturally breathed. Venting today is often done with soffit vents. Yet on historic houses, soffits are typically one of the nicer details. It’s not trivial or cheap to install venting in such cases.