[lcvw]

Is there a way to get your house (currently with hydronic gas heat) retrofitted for heat pumps that doesn’t result in either a ton of demo or ugly lines all over the exterior? I tried to switch over last year only to find the savings were not that great in my climate, and that it would have an unacceptable aesthetic cost.

[scott_s]

I had heat pumps installed in my house last year, to replace oil-based heat from baseboards. We have no drainage lines on the the front of the house, and only one bundle on the back. It follows the roof line, and then down a corner of the side of the house. So, yes, you will need drainage lines, but no, they shouldn't have to be all of the exterior. They should be able to be placed in an acceptable way. (Similar to, say, gutters.)

On the savings side: I think we're about even compared to oil. But I'm okay with that: we didn't have any air conditioning at all in the house, so we had no duct work. (We bought the house at the end of 2022 like this.) Since we were already doing significant work to install the duct work and get a new air conditioning system, I wanted to make them heat pumps to get off of oil. I think in the long run, we'll save money. I eventually plan on installing solar panels. And even if it's a wash in terms of money, I'm care about climate change, and I want to do what I can to electrify my house.

edit: After looking at other comments, I should clarify what we have. We have two condensers outside, and three air handlers inside. It acts like "central air", for the most part. We do have one mini-split, for the main bedroom, as we could not get ducts to it. My point here is that "heat pumps" do not necessarily mean "mini splits." My house is almost entirely centrally heated and cooled through duct work.

[sokoloff]

Air to water heat pumps exist that can efficiently supply flow/LWT* of 135°F, so if you can turn down your existing boiler to 135°F flow and maintain temperature in the house, you can retrofit to an A2W heat pump, which does not result in your home being festooned with linesets and covers running around the outside like plastic termite tunnels.

I also tried to switch in 2022 and found that it would literally never pay off due to the dramatically higher upfront project cost, and so a combi gas boiler now hangs on my basement wall.

* - LWT = "leaving water temp" aka "supply" aka "flow" depending on where you are in the world

[fullstop]

Mine has one pipe going into the basement, and the mains power connection. What sorts of ugly lines are you referring to?

[sokoloff]

I think probably the ugly lineset covers characteristic of lowest possible budget (and therefore overwhelmingly most common) installation of air-to-air heat pumps.

[fullstop]

I guess this depends on where you locate the heat pump. On mine, the insulated pipe and mains connection are within two feet of the building.

[sokoloff]

Is yours air-to-air?

[fullstop]

It is -- it looks just like an air conditioner plopped on a pad. There's two lines connected to it and leading into the house; one is an insulated copper pipe, and the other is the mains power connected to an electrical disconnect box.

[sokoloff]

Did they retrofit the linesets through the walls to the interior units?

Or do you have existing ductwork (which a house with hydronic gas heat probably does not have, or else they'd probably not be asking the question)?

[hedgehog]

Yes, a "heat pump combi boiler" will replace your existing hot water heater and boiler for heating leaving most of the visible infrastructure intact.

[ajross]

> Is there a way to get your house (currently with hydronic gas heat) retrofitted for heat pumps that doesn’t result in either a ton of demo or ugly lines all over the exterior?

It's literally the same physical design as an air conditioner. So... yes, unless you hate seeing AC units too, I guess.

[sokoloff]

A house with hydronic gas heat probably doesn’t have ducts right now. An owner of a house asking how to retrofit a heatpump without a ton of demo increases the likelihood that their house doesn't have ducts.

Adding ducts to an existing house qualifies as a ton of demo in virtually every case.

[leemelone]

No, I think you got it. You either have a lot of work to install ductwork or you're going to be doing lots of mini splits with ugly lines all over the exterior.