The GE Zoneline units are one of the most common brands found in motel rooms, and they are also often used in smaller apartments. They have models that use heat pumps for heating. You will want to look at the 5800 series, because these are the ones with a defrost cycle, and they can run resistance heat to maintain the room temperature during the defrost. Some of of the other heat pump models are really intended only for warmer climates, and they only run as heat pumps down to 40 degrees F or so, and below that they'll just switch over to resistance heat. Here is a link that might be useful: GE Zoneline dealer

@ Saltidawg: I do see your point... I suppose yearly maintenance is not that big of a deal, and it would be a good idea to have a yearly tune-up/inspection with any type of system anyway. Perhaps "maintenance" is not the right term for all my concerns... it's also the "inconvenience" factor, having to rely on deliveries and worrying about the tank running dry. I know that can be avoided by coordination with your oil delivery service, but I don't like getting on automatic fill-up plans when fill-ups cost so much. (If just using oil as back-up, it would be less of a concern though.) I'm also thinking about long-term costs, such as if the furnace ever had to be replaced (I'm guessing that would be 4-5K?), or if the oil tank had to be replaced (I'm guessing that would be about 2K?). My furnace should be ok for a while, but the tank is 60 years old, so I feel like I could have problems with it. If I consider keeping oil, I suppose I should have the tank inspected. It also has a broken gauge so that should be fixed too. (If I just got rid of the oil, I could avoid that.) It's about about $3,000 more to go with HP with electric back-up than HP with oil back-up. The additional cost isn't just for the electrical upgrade... it also includes going 15 SEER vs. 13 SEER, additional equipment and labor, and removal of oil tank. I would have a higher SEER, sufficient electrical power if it's ever needed for anything else in the house, the tank out of my house, never having to worry about it leaking... also approx. ~20%-ish saving over oil back-up heat if oil stays at $4/gal, potentially more if oil prices go higher. $3,000 isn't a trivial amount, but I feel like once that conversion is done, all you ever have to worry about is one system, the heat pump... no oil furnaces, no oil tanks... so over time, I feel like money would be saved. (Correct me if I'm wrong... an HP with oil back-up should have about the same lifespan as HP with electric back-up, shouldn't it? There's additional electrical components to worry about, but I feel like it's usually the compressor that craps out over time, and compressor usage would be about the same either way, wouldn't it?) That being said, you do have some good points, and I will take them into consideration. If my oil tank is ok, maybe it isn't worth the extra 3K at this time to get rid of oil. If it's not, well then I'd rather take the 2K that would have to go to replacing the oil tank, and put that towards getting rid of oil. @ david_cary and weedmeister: Thanks for the info. I'm still a little confused about actual percent savings, but I think if I'm going to go through with this, it would be ideal to go with a 15 SEER, which I may not be able to do that if I keep the oil. Since my current A/C unit is 10 SEER, I think I would save a decent amount on A/C bills with 15 SEER. (I wish I knew how much of my electric bill actually goes to A/C and what goes to other stuff, but I don't really have a way to tell that.) @ cindywhitall: HP with oil back-up would not have electric back-up strips. If the oil craps out, then it would come down to repairing/replacing the oil furnace, adding electric back-up later, or adding some other back-up later. If I wanted to keep oil AND add electric back-up also, it would cost more than the current higher cost route, and I'm not sure it would even be possible. Oil prices to me seem a lot more unstable than electricity, but that's anybody's guess. Yes, I know I need to make a decision soon, before it gets cold. I know I can easily get through until mid-to-end October without heat, but not beyond that. My electric bill doesn't have the costs on one line either... I added up all the "per kwh" usage charges, and that's where I got the $0.114. My August bill was for acutal usage of 1903 kwh. Does your bill have gas on it too? (BGE puts electric and gas both on the same bill, but since I don't have gas, my bill only includes electric.) I don't know how NJ's rates are, but MD (BGE) did have a pretty big price increase around 2007/2008... however, since then electric rates have come down every year. I use an alternate supplier for additional savings. Rates are only guaranteed until May 2013, and they'll be announcing future rates this fall. My winter rates with the alternate supplier are the same as summer rates. FYI - I am female. My husband doesn't think it's necessary to do an HVAC upgrade, so that's why I'm looking into it. He thinks we should either use only wood and spaceheaters (which we did last year and was AWFUL), or get some oil, but try to make one fill-up (~250 gal, $1000) last all winter, which is unrealistic. Besides the oil issue, we have some other HVAC issues that really should be addressed (we should have some additional ductwork, the A/C doesn't work well on the 2nd floor, etc.), so I think it's really necessary to do something NOW. @mike_home: As mentioned, the tank is one of my concerns, being 60 years old. I wouldn't buy (another) house with all oil either, and if I could go back in time, probably wouldn't have bought this one. BUT - I can't change that now, so here I am :) SO WHERE I AM RIGHT NOW: I know oil alone for heating is not a good option, and something really should be done. I still need to get some more estimates, and I'm honestly not sure yet about keeping the oil as back-up or not. I don't see a big advantage to keeping oil, except less up front cost, and the off chance that oil prices could go lower one day (which I don't ever see happening). I could keep the oil as back-up now and look into other back-up sources later. I don't think we'd really need MUCH oil for back-up... I'm not looking for a toasty 75 degrees... more like 65 degrees most of the time is good enough. We also have the wood stove too. The only drawbacks to keeping oil are that we may only be limited to 13 SEER, and I'm worried about the condition of the oil tank... also it's a good time to remove the 60 year old tank NOW while it's empty... so it's a tough call. No one has commented on geothermal, but I may look into that too... doesn't hurt to get an estimate, right?

Hello Your heat pump air-to-air sounds like the best options. If you dont need to use it for water the COP is quite high, usually COP-3-4. The COP means a ratio of what you get out vs what you put in. The COP of 3 is 3 times the heaat of what you put in. There are a number, some that get a COP of around 5 using source of 30F. Others list between 3-4 quite generally. Carrier is a maker of one type which has a COP of 3 and is a small size. When the source (outdoor temp) is low the COP goes down as does the output. (Below freezing especially). Its worth having an oil or wood or gas heater to go with the system as back up. Heat pumps that can heat water have to work harder as the water is warmer than the air used in buildings, so they use expensive CO2 heat pumps which will set you back about $5K easily. Therefore I would suggest keeping a boiler system, outdoor boiler. An indoor stove needs fresh air which is not ideal for heat pump system which works ideally with heat recovery on the ventilation system (extract heat from waste air at 90% or so efficiency). A neat approach may be to operate an air -to-air heat pump, aim for as high a COP as possible, but install a gas boiler if you have this. The smaller boilers, condensing systems, are surprisingly cheap. If you install a waste water heat recovery system which is just aa heat exchanger on you waste water from your shower, you can half the energy you need and thereby get by with a smaller boiler and consume only about 4-5kWh/day for shower water. A condensing boiler works most efficiently when working with water heating rather than central heating, and plus, the typical condensing system now heats so quickly that you dont need a hot water tank, reducing loses. You would still have at least 15KW available for heating the home. This can be done by putting in a heating loop into the air ducting that is shared with the air-pump. This could be a compact fan assisted system. There would be expense in heating controls for all the ducting. However, if you cannot put in ducting, then you can install a water radiator central heating system. To work with a heat pump, you can go for the super-efficient CO2 based systems that are emerging but expensive. The efficiency can be raised if the heat is needed at a low temperature, so requiring either under-floor heating or a 'fan assisted radiator' which extract more heat and can return the water to the heat pump much cooler than normal radiators, and require a lower temperature, raising COP. I would go with: Waste water heat exchanger ( I guess $500 est with capital cost $200-$300 plus basic installation if incorporated with a boiler installation and pipework anyway) -this will reduce the energy requirement of the condensing boiler, potentially allowing a smaller system. Condensing boiler - 15-25kW output, 90% efficient, capital cost $500 ebay Air-to-Air heat pump (in loft) - COP 3-5 (later figure seen in an Austrian GSHP but should work with airsource unless outside air is usually very cold?) cost? controls? Fan assisted radiator in ducting for backup (run off boiler)? Ventilation heat recovery

"Does the different type of construction (concrete block vs 2x6) between old house and new addition necessitate a zoned HVAC system? " No. "Would a ductless dual heat pump in the new addition suffice? I'm trying not to kill my already tight budget." Depends on the layout of your addition. If its open plan, a ductless minisplit might work. If it's several distinct rooms, you probably need a ducted system.