Air-to-Water Heat Pump instead of oil furnace for home heating?

[bbattani]

Hello

I have a home in central MD with an oil-burning furnace heating system for the 1st floor of the house. Heat is delivered via hot water baseboard heaters located in all rooms. We do not have access to natural gas. Last year, I replaced all the original builder-grade windows with Energy Star rated, low-e, argon-gas filled Viewpoint windows.

The furnace is pretty old (30+ years) and I'm going to need to upgrade it before it fails. I also have an underground storage tank I'm not fond of, and rising oil prices with unstable future costs have me thinking about other options besides oil as my fuel source.

I do like the baseboard heaters and I like the efficiency of using water instead of forced air. I would prefer to keep this component of my system.

I like the idea of geothermal but the upfront costs worry me.

My question to the community is what do you think about an air-to-water heat pump system to provide heating and hot water through the existing system? Are there models out there that can achieve the water temp necessary for heating in winter? Would I need a supplementary system for a few months out of the year? What are the maintenance needs of a system like this? I like the idea of using air instead of oil and think I could capture some efficiency. My electric costs are pretty reasonable (8.5 cents/kWh supply). I'm currently burning about 1,000 gallons oil per year for heating and hot water.

Trying to understand the pros and cons to make an educated decision. Also thinking about propane furnace instead of oil because of commodity costs and efficiency.

I appreciate any feedback. Thanks!
Brian

[BradC]

Dude.

http://ecorenovator.org/forum/geothermal-heat-pumps/

All the cool kids are doing it.

Let me rephrase that. I'm getting a cop of over 4.5 with stuff I put together from the council tip (cooling not heating). Geo is cool and fun.

[Tesla]

I have gas to this apartment in Sydney but have turned it off after receiving a bill for AUD$64 and only using AUD$8 worth of gas - the rest was gas line rental and tax. so be wary of the gas and possible increases in the future. An electric heat pump can give good efficiency and heat either water or air. Also consider solar hot water heating if an option in your climate. Sorry I am not familiar with imperial units.

[MikeHolm]

Brian,
I don't think it is wise to try a heat pump with your present baseboards. They are meant for 150-180F (65-82C) water temp which you will never get with a heat pump in North America. If you double the amount of rads in the house you may be able to bring down the water temp enough to make it happen or get some of the European panel rads (Stelrad, etc) that can run at lower temps.


Check to see if heating with oil is roughly equal to the cost of electricity. If so, the heat pump can do the temps above 25F outdoor temp and added electrical can do the work below that temp.

With a propane boiler, you will gain about 10% efficiency but the cost is often as bad as oil. If you go with something electric you can also close off the old flue and lower the heat loss a bit.

[JackPreacher]

Hello Brian
What levels of insulation does your home currently have? You mentioned the new windows as being energy efficient but what about the loft/attic and walls?

It may be possible to run your baseboard panels at a lower temperature 24/7 if the heat losses a very low.

[The MG Pony]

If you can get the large cast iron radiators, they preform very well at a lower temp, just heavier and take up a hair more space. Heat pumps can and will do what you want feectivily.

As will propane with a condencing unit but must look at the priceof lpg and the availibility for the futur. if you rent a tank that adds to the cost, buy a tank then you need the 10/20 year recerting of it.

Your first step should all ways be more insulation no mater the direction you choose!