Heat Pump w/radiators ?
 

My house currently uses and oil furnace with hot water radiators. The cost of heating oil is ludicrous, and is likely to go up.

I'm hoping to supplement my oil heat by placing a heat pump (preferably a reverse cycle chiller) in-line with the oil boiler, and use the heat pump most of the time, and only run the oil in situations where the heat pump becomes inefficient or ineffective (such as extreme cold).

Has anyone done this, or something similar? Know anyone who has? Heard of anyone who has?

I know they do the heat pump with hot water radiators thing in southern England, where the climate is a little milder than here (Eastern Pennsylvania), but I can't find any info on anyone doing this anywhere in the US.

Does anyone have any other suggestions as to how to get off of oil in a 105-year old brick twin where running ducting would likely be very expensive (correct me if I'm wrong about that).

I don't know anything about heat pumps, but...

The issue with getting off of oil isn't ducting; you can just heat your water with something else. What fuels are available? Is there natural gas in the street? Is there enough yard for a propane tank? With the price of oil now, even electric heat is looking reasonable.

A gas or propane burner can use the same exhaust pipe as the oil burner. It may be able to use all the same equipment and just change out the burner unit itself. All you have to do is pipe in the fuel, which shouldn't be too big of a project.

For electric, you would have to use an electric water heater, which I'm not sure if they make them big enough for heating the house or only big enough for domestic hot water (faucets/shower). You'd probably have to have a bigger service and panel put in.

I did a price comparison that measure cost per heat generated (you give it the local prices for oil, gas, propane, electric, pellets, etc and it makes a calculation based on efficiencies of burners and the # of BTU's per unit of fuel) and the result showed that Oil, Propane, and Gas are all very expensive right now, electric baseboard heat was OK and electric heat pump was best. Now, I wouldn't get quite the full benefit of an electric heat pump because they are usually used with a lower temp output than is necessary for a hot water radiator system, and the efficiency goes down when you turn the temp up, but I'm pretty sure it would still be the cheapest (per month).

Any and all opinions, insights, and data are welcome...

How about solar? The 70s style direct solar water heating roof panels should work in series before your oil burner. Will the neighborhood tolerate it or claim that it's too ugly?

My house is "historic" so I think panels on the roof are out. I'm a little nervous they might not even let me put a heat pump on a pad out back. Plus, I'm not sure it would be a good idea to panels up on the slate roof.

Keep those ideas rolling... Maybe someone else in addition to theholycow has some suggestions as well?

An electric hot water heater won't cut it. You will need a boiler. You can get small electric boilers, but they are expensive to run. It will be a lot cheaper to install a natural gas boiler.

-Jay

I just thought of something else... My parents saved a lot on heating their large 5 br colonial by converting the fireplaces from wood to ventless propane. In the winter they have the fan on the heat pump set to run continuously, and the fireplace has a thermostat on the burner. Enough heat was circulated throughout the house that their winter electric bills were really low. They only have to have the propane tank filled once a year, and that runs the fireplace and the stove. The best thing about the ventless gas logs is that 100% of the heat generated stays in the house, none of it goes up the flue.

-Jay

I read some time ago about a person who replaced his solid grate with stainless steal tubing. He had a pump to bring in outside air, ran it through the tubes and hot air came out in to the room. He just used newspaper or anything else to burn to produce the hot air. Simple and effective.

I work in a HVAC company in Upstate New York and we've been specializing in Geothermal heat pumps for the past thirty years. About 6 months ago we put two heat pumps in an old house with radiators as a rather expensive "experiment". The owners kept their boiler as a back-up/supplement. They couldn't be happier with the out come. The back-up boiler hardly ever comes on and it's only if there is a serious cold snap. You'd have to have a heat load calculation done on your house and see if your radiators are oversized. Many times in old houses they would oversize the radiators because "bigger is better, and biggest is best". The one house we worked on had to beef up their insulation with spray foam insulation and they examined every part of their house with an IR camera for heat loss. Just some suggestions. But it is possible and it's possible in much colder conditions than Penn.