I posted about a possible conversion over to geothermal here several months ago, after my local heating oil distributor told me their price for home heating oil (which we use to heat our 4500 sf home in SE NY State, 50 miles NW of NY City, natural gas lines don't come up here, too rural) was $4.89 per gallon. Right. We used 1477 gallons last winter.
So I looked into geothermal. Got two price quotes. The right way to do up our house would have cost a whopping $60,000. After that we would have needed to spend another $10,000+ to remove every baseboard heating unit in our 4500sf house and re-trim, paint and wallpaper all those rooms. Still, at nearly $5 per gallon @ 1477 gallons, you could almost make the case for such an outlay for a system that would reduce us from nearly 1500 gallons of oil to zero. I kept researching.
We wound up taking the middle road. We installed an Energy Kinetics System 2000 boiler/hot water system just like this:
That will take us from 1500 gallons of oil down to <900 gallons. Most efficient boiler on the marketplace, it's been around for nearly 30 years. I did a lot of research on this. They are reliable if a touch finicky to service due to the sophisticated electronic controlling unit, but becoming more mainstream every day. Our local contractor is excellent, there are several good companies here that service these including our new oil supplier.
We also changed our oil suppliers and lowered our oil cost by about 40 cents per gallon. Between that and lower prices on global oil, heating oil prices are closer to $3 per gallon ($3.39 last time I checked, I'm sure it's lower now) than $5.
Further, we removed the two old cranky in-wall A/C units in our finished basement/office (that's where we work every day) and buttoned up those openings. Replaced them with one 12,000 BTU ductless mini-split heat pump ($2000) which is 13 SEER (old units were 10 SEER) but more importantly makes our finished basement far less drafty in winter.
The next phases will be:
• Closed cell foam spray insulation in our attic. $4,400. They claim that will reduce oil usage by 30%, I'm hoping for 20%, which would bring us down to 700-750 gallons of oil annually. Our home is well insulated with excellent Anderson windows (it's only 11 years old) but the attic insulation is a bit light, the closed cell foam would be like putting a winter hat on our head to replace a light baseball cap. It would also reduce the load on our A/C gear tremendously.
• Replacing our 11 year old central A/C unit with a new much higher efficiency 16 SEER heat pump with a variable speed air handler. That can generate heat through our a/c ducting rather efficiently when the outside temps are above 40º or so, which will largely relieve our boiler of home heating duties except for 3-4 months of the year. That's a 5 ton unit (same size as the current old unit). A bit undersized for our home perhaps (it's only for the 3200 sf upstairs, not the finished basement), but we're thinking that the attic insulation will reduce the load enough so that it will be fine. $9500 for this measure, two three ton units would be closer to $15K, don't want to go there, too complex and expensive. We only use A/C three months annually and would be using this to offset the heating load on our boiler in the shoulder months, should work fine, my heating contractors agree.
That last measure should theoretically lower us to <600 gallons annually in combination with the attic insulation. We'll probably do that next winter after the new heat pump/ac unit. Trying to do this in phases.
So from nearly 1500 gallons of home heating oil to about 600 gallons. Total cost outlay about $26K. We really have to do it. House will be more comfortable, have better resale value in the long run and will obviously have a much lower carbon footprint.
The last ultimate measure would be to install a solar hot water assist array on the roof, current pricing is $20K, but I'm sure that cost will drop. That lowers your oil consumption another 30%+, which would bring us down to <400 gallons. I'd only go there if oil went to $6+ per gallon. That would be nearly double current prices. We'll see.
The difference between the old boiler and the new one are startling. The old boiler sounded like a jet plane. The new one is virtually silent. The old unit was CONSTANTLY firing up to keep the water hot. The new one literally fires up about 20% (or less) as frequently. The System 2000 can provide 40 gallons of new hot water in 12 minutes. The old one took 45 minutes. That's almost unlimited hot water. And it does this for .2 gallons of oil per day, that's less than 80 gallons of oil annually. I'm sure that's 1/4 of the oil the old system needed to provide our hot water. The new mini-split A/C in my office has a wireless electronic remote and it's far quieter (the compressor is outside). 13 SEER vs. the old one which was 9 SEER. These units are like replacing a 1978 Gremlin with an F22 jet.