Ideas for how to be done with oil?

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twcronin

New Member
Oct 18, 2021
8
Wayland, MA
Hi all,

I'm wondering if anyone has ideas for how we can get kick our oil habit and the nasty storage tank (/potentially massive leak liability) that goes with it. House is ~2200 sqft including area of a finished basement, not super tight (~1945 construction, heavily built) but insulated during some house work and further by a Mass Save contractor. Our HVAC setup is as follows:
Supply:
-Oil boiler, rated for ~150 MBH hot water (but that's now massively oversized)
-MF Nova wood stove in main living room (rated for up to 50 MBH)
-Central A/C with outdoor compressor/condenser unit and air handler/evaporator in attic (don't know specs on system size offhand...)

Distribution:
-Hydronic baseboard radiators with two zones through the house for oil heat
-Ducted A/C system
-Indirect DHW sourced by oil boiler

Last year we used ~500 gallons oil for heat+DHW and between 2-3 cords of wood. Prior to wood stove install it was ~1000 gallons oil per year.

Any thoughts? Replace the A/C with a heat pump system (that is generally doable, right?) and transition to a wood pellet or cordwood boiler or propane for the coldest weather? Double up on heat pumps with one serving heat/cold to air handler and the other sending water to the baseboards?

Thanks!
 
There's a few ways to skin that cat.

We replaced a wood/oil combo boiler with a gasifier wood boiler and electric boiler, and ordinary electric hot water heater, in 2012. Yanked out everything oil related. No regrets, should have done long ago. Have since added a couple mini-splits for shoulder season 3-4 years ago and have not used the electric boiler since. Will likely add one more next year. My biz partner just replaced his oil furnace with a Daikin central heat pump system. Needed all new ductwork. Not cheap. Just completed. Time will tell how that turns out. If you want to keep hot water heat, I would try to retrofit lower temp emitters in, somehow, as a main consideration. Cast rads or flat panels. Or throw a whole bunch more baseboard at it. Typical baseboard really hampers overall efficiency because of the high supply temps needed. Going to a wood boiler might not be easy, most also need storage. Unless you just go outdoor boiler. Pellets might be an option depending on the supply situation in your area. They're not cheap. Natural gas also if you can get it. A guy here is having decent success by combining a new electric boiler with lower temp emitters, to replace oil with. But you'd need some kind of provision for a power outage.
 
Interested, but I suspect it's going to be hard amortize any reasonable ROI on just 500 gallons per year. Heck, that barely qualifies as a "habit"!

Got room for a wood stove?
 
I concur with ashful. If the motive is purely financial, you're not going to like it.
Other motives may exist and justify things, though.
 
Interested, but I suspect it's going to be hard amortize any reasonable ROI on just 500 gallons per year. Heck, that barely qualifies as a "habit"!

Got room for a wood stove?
Hah, fair! We've already got one wood stove and I suppose could put another in to replace the oil boiler but it's a crappy place to put a stove since it would sit in the uninhabited utility room of the basement, and would leave the hydronic heat system stranded and unused.

I should say that ROI is not the main motivation (agree, it's very hard to justify yanking out an oil boiler halfway through its lifespan when we use so little oil for heat, but $5.50 per gallon does change that calculus some...). We do have some concern about the potential for oil tank leakage, which is very difficult to insure and could be a very large expense based on MA requirements for cleanup -- so it would be nice to get rid of that liability. That plus aesthetics plus a values-based desire to move away from oil are the main considerations, rather than a purely financial ROI perspective.

Do people ever pair an interior air-source heat pump with a wood stove in an unused part of their house? I've read about using heat pumps in a basement space for DHW but not for hot water to supply to radiators -- which is presumably much more heat demand and would cool the basement space too much unless compensated by a lot of waste heat from something else. This would be a wacky solution...
 
I'm always surprised at how common oil furnaces seem to be out east. Here they are very uncommon mostly having been replaced by natural gas or LP furnaces. My place is rural and I don't have access to natural gas so LP is the first choice. If it is an option, why not replace your oil burner with LP or natural gas furnace as back-up to your wood stove? Gas is vented with PVC pipe, so you might free up a chimney flue to use for a wood burning furnace too.
 
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I'm always surprised at how common oil furnaces seem to be out east. Here they are very uncommon mostly having been replaced by natural gas or LP furnaces. My place is rural and I don't have access to natural gas so LP is the first choice. If it is an option, why not replace your oil burner with LP or natural gas furnace as back-up to your wood stove? Gas is vented with PVC pipe, so you might free up a chimney flue to use for a wood burning furnace too.
And it would be “right sized” compared to your admittedly huge oil boiler.

Only 500 gallons of oil per year in MA seems low. That’s great for a 1945 build.
 
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A few comments, but dont shoot the messenger;)
If you have a mortgage and house insurance, you probably need a backup conventional heating system.

A conventional house no matter how tight is going to have a pretty hefty design heat load and that means someone has to be there 24/7 to keep the place warm with a woodstove during the coldest times of the year. There are zero net energy and passive homes built in Mass that can go days without any heat input but might as well burn your house down and start from scratch compared to trying to do it with a conventional home.

IMO the only way to go oil free is to do what I and others have done and that is installing a indoor wood boiler with thermal storage or a pellet boiler with bulk fuel storage if you have a bulk pellet dealer nearby that delivers them in bulk with pneumatic system. Both are a $15, to $25,000 hit. (Currently the only indoor wood boilers that meet the EPA standards are gasifiers so use wood boiler and gasifier interchagably). Cord wood can cost less if you have a place to cut wood or willing to scrounge wood. Some members do well by talking to trees services and getting it for free or for low bucks. This requires dedication and time and I suspect most of us who burn wood do it partially for intangible benefits. A Pellet Boiler takes far less homeowner time but costs more to buy the fuel. Wood boilers do not feed themselves and when it gets really cold, they will probably need to be run once a day to boost the storage temp up, a pellet boiler with bulk storage and automatic feeder can go for weeks, its the closest thing to an oil boiler. The only gotcha with a boiler that uses bulk pellets is there are not a lot of sources who deliver bulk pellets, the big heating distributors that are snapping up local and small heating fuel suppliers do not mess with pellet deliveries and some folks have been stranded with no supplier when the local guy sells out. Do your research.

BTW note I was specifically referring to indoor wood boilers, I will refer you to a state website on Outdoor Wood Boilers https://www.mass.gov/guides/heating-your-home-with-a-wood-burning-appliance. No matter how "clean" it is, an OWB is going to be heating the outdoors and the ground while an indoor wood boiler, typically in a basement, means any heat radiating out the piping and boiler casing goes into the house.

The good news that you probably do not want to hear is at 500 gallons of oil per year, you can pretty well solve the oil tank leakage problem by installing a Roth type oil tank https://www.roth-america.com/product/oil-storage-tanks/double-wall-heating-oil-tank/. They are double contained with a lifetime leakage guarantee. The fuel supply system from the tank to the boiler is modified so that the oil is pulled up from the tank instead of draining by gravity out the side. Any heating oil company can make the switch in about 4 to 8 hours. The biggest limitation is if you can get the oil one out and the new one into the basement. The other thing you can do is replace your boiler with "low mass cold start" boiler. A typical older boiler stays hot year round, that means a lot of wasted heat during the summer, spring and fall when the heating demand is low. One company pretty well owns that market and its Energy Kinetics who make the System 2000. It uses a conventional burner so a typical service tech can work on it. Its likely that there is supplier that offers a biodiesel blend of heating fuel in your area and as the years go on I expect the blend ratios will go up. My guess is a cold winter in New England may finally force some new pipeline capacity to built into the region so Natural Gas will probaly replace heating oil but its guess at this time as the US government needs to swap over the nations housing stock to electric heating away from oil and gas in order to meet climate commitments.

The other thing to consider is that there are going to be lot of incentives to install minisplit type electric heating units. They are hassle free but with the current electric rates in Mass I would be hesitant to recommend them as a primary heating source but thrown in with a mini split is that they are super efficient air conditioning so if you cool you house in the summer the savings can be used to pay for the higher bills in winter.

The Mass Save and equivalent programs are a great program, but they are going for the "low hanging fruit", There are ways to further reduce heating demand in an older home but its starts to get radical with long paybacks. Cutting your 500 gallons in half would probably require gutting the interior or exterior walls, foaming the existing exterior wall cavities then adding a couple of inches of insualtion board on the inside or outside, major insulation in the attic, removing some windows on the north and possibly east and west walls and replacing the ones that are left. This is serious move your stuff into storage and go way and live somewhere else for a few months type of work and given the shortage of trades and big demand for new housing in Mass, it would be very hard to find someone who would even do the work.

BTW, I have a 1987 Full Dormer Cape in Northern NH with 6 inch walls, good window and fairly efficient construction for the era plus a Mass Save equivalent retrofit about 10 years ago. I have solar hot water so no need for hot water from the boiler. The two years prior to putting my wood boiler with thermal storage on line I was burning around 300 gallons per year with a "hot boiler" that was shut down in the summer and a wood stove I used on weekends. I havent used oil to speak of in the last 6 years. I go through 3.5 to 4 cords of wood a year that I cut and process myself. My wood boiler is an "ancient" 1980s vintage wood/coal boiler that was probably based on a design from the 1930s. If I went with a gasifier and bigger storage, I could probably reduce my wood use by a quarter to a third. I also have a Roth oil tank I bought off craigslist waiting for me to get motivated to install it to replace my 30 year old steel heating oil tank. If I am not home to feed the wood boiler, the system automatically switches back to oil with no intervention on my part.
 
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I'm always surprised at how common oil furnaces seem to be out east. Here they are very uncommon mostly having been replaced by natural gas or LP furnaces. My place is rural and I don't have access to natural gas so LP is the first choice. If it is an option, why not replace your oil burner with LP or natural gas furnace as back-up to your wood stove? Gas is vented with PVC pipe, so you might free up a chimney flue to use for a wood burning furnace too.
In areas that had coal, multiple coal stoves from the 1800's were replaced with a central heating coal furnace in the basement and heat ducts were installed. Later, oil burners were retrofitted to many coal furnaces. When the combustion chamber finally gave up, a new oil furnace was installed since the tank and heat ducts were there. In few towns where natural gas was available, central gas furnaces and ductwork replaced the multiple coal stoves. Water circulation systems were mainly found in wealthy homes being much more expensive than ducts. Most older homes have the remnants of multiple chimney connections were the stoves were as well as the coal bin. Those that can't afford a new heat pump and air handler to replace furnace systems, and as gas and electric prices rise, multiple stoves are more appealing. Almost came full circle!
 
I literally just did this project last month. Took out an old oil boiler and put in a high efficiency propane combi boiler, does baseboard heat and hot water. I also had concerns about the oil tank, which was buried for almost 40 years. Luckily, it was in good shape. We had to have it properly abandoned, which wasn’t cheap. The toughest part was coordinating everything so we weren’t without heat and hot water for longer than a day or two. We had to have propane tanks installed, grounded, and the line pulled to the new boiler obviously. There were a few kinks, and it was a lot of stress for me. But it seems to be working ok. We burn wood mostly for heat when we’re here, so that helps a lot. But oil was $6 a gallon when we switched. Paying $2.50 a gallon for propane. Plus the old boiler was almost 40 years old, so I wanted to get ahead of it on my terms, not at 2 am when it’s 5 degrees out and it decides to finally go up.
 
A few comments, but dont shoot the messenger;)
If you have a mortgage and house insurance, you probably need a backup conventional heating system.

A conventional house no matter how tight is going to have a pretty hefty design heat load and that means someone has to be there 24/7 to keep the place warm with a woodstove during the coldest times of the year. There are zero net energy and passive homes built in Mass that can go days without any heat input but might as well burn your house down and start from scratch compared to trying to do it with a conventional home.

IMO the only way to go oil free is to do what I and others have done and that is installing a indoor wood boiler with thermal storage or a pellet boiler with bulk fuel storage if you have a bulk pellet dealer nearby that delivers them in bulk with pneumatic system. Both are a $15, to $25,000 hit. (Currently the only indoor wood boilers that meet the EPA standards are gasifiers so use wood boiler and gasifier interchagably). Cord wood can cost less if you have a place to cut wood or willing to scrounge wood. Some members do well by talking to trees services and getting it for free or for low bucks. This requires dedication and time and I suspect most of us who burn wood do it partially for intangible benefits. A Pellet Boiler takes far less homeowner time but costs more to buy the fuel. Wood boilers do not feed themselves and when it gets really cold, they will probably need to be run once a day to boost the storage temp up, a pellet boiler with bulk storage and automatic feeder can go for weeks, its the closest thing to an oil boiler. The only gotcha with a boiler that uses bulk pellets is there are not a lot of sources who deliver bulk pellets, the big heating distributors that are snapping up local and small heating fuel suppliers do not mess with pellet deliveries and some folks have been stranded with no supplier when the local guy sells out. Do your research.

BTW note I was specifically referring to indoor wood boilers, I will refer you to a state website on Outdoor Wood Boilers https://www.mass.gov/guides/heating-your-home-with-a-wood-burning-appliance. No matter how "clean" it is, an OWB is going to be heating the outdoors and the ground while an indoor wood boiler, typically in a basement, means any heat radiating out the piping and boiler casing goes into the house.

The good news that you probably do not want to hear is at 500 gallons of oil per year, you can pretty well solve the oil tank leakage problem by installing a Roth type oil tank https://www.roth-america.com/product/oil-storage-tanks/double-wall-heating-oil-tank/. They are double contained with a lifetime leakage guarantee. The fuel supply system from the tank to the boiler is modified so that the oil is pulled up from the tank instead of draining by gravity out the side. Any heating oil company can make the switch in about 4 to 8 hours. The biggest limitation is if you can get the oil one out and the new one into the basement. The other thing you can do is replace your boiler with "low mass cold start" boiler. A typical older boiler stays hot year round, that means a lot of wasted heat during the summer, spring and fall when the heating demand is low. One company pretty well owns that market and its Energy Kinetics who make the System 2000. It uses a conventional burner so a typical service tech can work on it. Its likely that there is supplier that offers a biodiesel blend of heating fuel in your area and as the years go on I expect the blend ratios will go up. My guess is a cold winter in New England may finally force some new pipeline capacity to built into the region so Natural Gas will probaly replace heating oil but its guess at this time as the US government needs to swap over the nations housing stock to electric heating away from oil and gas in order to meet climate commitments.

The other thing to consider is that there are going to be lot of incentives to install minisplit type electric heating units. They are hassle free but with the current electric rates in Mass I would be hesitant to recommend them as a primary heating source but thrown in with a mini split is that they are super efficient air conditioning so if you cool you house in the summer the savings can be used to pay for the higher bills in winter.

The Mass Save and equivalent programs are a great program, but they are going for the "low hanging fruit", There are ways to further reduce heating demand in an older home but its starts to get radical with long paybacks. Cutting your 500 gallons in half would probably require gutting the interior or exterior walls, foaming the existing exterior wall cavities then adding a couple of inches of insualtion board on the inside or outside, major insulation in the attic, removing some windows on the north and possibly east and west walls and replacing the ones that are left. This is serious move your stuff into storage and go way and live somewhere else for a few months type of work and given the shortage of trades and big demand for new housing in Mass, it would be very hard to find someone who would even do the work.

BTW, I have a 1987 Full Dormer Cape in Northern NH with 6 inch walls, good window and fairly efficient construction for the era plus a Mass Save equivalent retrofit about 10 years ago. I have solar hot water so no need for hot water from the boiler. The two years prior to putting my wood boiler with thermal storage on line I was burning around 300 gallons per year with a "hot boiler" that was shut down in the summer and a wood stove I used on weekends. I havent used oil to speak of in the last 6 years. I go through 3.5 to 4 cords of wood a year that I cut and process myself. My wood boiler is an "ancient" 1980s vintage wood/coal boiler that was probably based on a design from the 1930s. If I went with a gasifier and bigger storage, I could probably reduce my wood use by a quarter to a third. I also have a Roth oil tank I bought off craigslist waiting for me to get motivated to install it to replace my 30 year old steel heating oil tank. If I am not home to feed the wood boiler, the system automatically switches back to oil with no intervention on my part.
Thanks for the thorough reply! I agree that we certainly need a central heat system of some sort, and as much as I like cutting and processing wood (it's effectively free in log length around here from tree services), a cordwood boiler might not be the best idea in terms of complexity of house functioning and ease of use for all household members.

We blew in insulation when doing some work on the house, put new windows in, and had state/utility-subsidized additional insulation and air sealing work done. They did a crappy job with the additional air sealing, but based on energy use I've estimated the whole-house energy loss coefficient as now somewhere in the range of 300-400 W per degree C. Based on the blower test, probably ~100 W/C of this is infiltration and the remainder conduction. Nowhere close to a passive house, and agree, not getting there without very major changes that don't make sense to make. At a -15 C cold month temperature design standard, this means a minimal central heat system needs to be able to supply something like 50-60 MBH.

We do use A/C in summer and have a ducted central air system. That system is about 12 years old, and seems slightly underpowered (2 tons nominal, has lost some efficiency) for the amount of cooling we want in summer. I'm getting some quotes for how much this would cost to upgrade to an air source heat pump system which could do double duty heating and cooling. Conveniently the rooms served by the central air do not include the living room with the wood stove, so switching the A/C to an air source heat pump might be a nice balanced option that would get the house through all but the coldest weather (I doubt we would size an ASHP unit to meet 5 tons of heating demand, as that would be expensive and massively overpowered for cooling needs). But ideally we could run a small ASHP system plus the wood stove for a winter and see how much further down the oil use came, then consider options for kicking out the oil entirely -- whether it be cordwood, pellets, propane, or another heat pump wired to the radiators + DHW.

Or we could decide to stick with the oil and upgrade the tank -- that's also a good idea.
 
Well, there's lots of options, most of which have been covered already just pick your poison. I'm also in the camp of wanting to get rid of my oil boiler(only provides FHW for heat) and the path that i'm hoping to follow works out. There are really good rebates for heat pumps through Mass save, up to $10k, so you could look into going heat pumps for heat and ac, then ditch your boiler using a good woodstove or pellet stove as your primary heating system. You could then also get solar panels to help pay for this. For DHW, i suggest a hybrid hot water heater or on-demand system if you have propane. Currently i have hybrid for DHW and burn wood for my primary heat, dont have central AC, so i would be very happy to get some mini-splits put in to handle AC and heat for spring and fall. I'm still up in the air for solar since i'd need to do a roof mount system and not the biggest fan of those. But it'd give me "free" hot water and ac if i did. Heat pumps do have some draw-backs though and really hoped the industry would up it's game on them but i dont see that happening so we're stuck with the units we can get.
 
How old is the AC unit? How does it cool during the hottest 5 days of the year? How many amps is your main electric service?

A heatpump with resistance heater backup is a no brainer. There will be good incentives for the switch staring next year. A heatpump water heater is also a great choice. Bigger (80 gallon) is better if you have more than 3 in the house as it can run in heatpump only mode in a basement that’s 55 degrees all winter.

I love my heatpump and woodstoves combo. Really spend some effort air sealing well. That’s the best money spent.

Right now we are still waiting on the efficiency requirements for the IRA incentive money.

I don’t see keeping the oil at backup if you have a woodstove. It’s just more to maintain.
 
I'm always surprised at how common oil furnaces seem to be out east.
All us practical. The ROI is rarely there, for tearing out and replacing a working oil-fired hydronic system, which are nearly ubiquitous in the masses of older homes dotting the eastern seaboard. I’ve looked at it, and I won’t live in this house long enough to justify the cost of making any substantial change to my current system.
 
I did a bit of research and in addition to the lack of natural gas in the streets, heating oil was also regarded as safer than natural gas. You rarely hear of a house burning down by a heating oil fire, it takes a lot of heat to vaporize fuel oil, that is why its classified as noncombustible. On the other hand, homes blowing up from natural gas leaks make the press quite often. Same with propane. Propane is heavier than air so it tends to pool in low spots and can build up. Natural gas is lighter than air, but in a closed house it just means a bigger boom if it goes over the LEL (5%) All three can be used safely but for some reason there are more short cuts taken with gas and propane installations and its lot easier not to notice a minor gas or propane leak.

My mom was deathly afraid of natural gas in a house. She did not even like it in the street as its not unknown for a natural gas leak in the street to follow an old pipe trench into a basement that had gas at one point but no longer had and cause an explosion.

The other aspect is similar to wood burners with respect to self reliance, a full tank of heating oil, several cords of wood or a ton or two of pellets in the basement is something you can depend on no matter how crazy the rest of the world is. Propane can have the same attribute but not a lot of folks have bulk tank, most rely on smaller tank filled frequently.
 
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I did a bit of research and in addition to the lack of natural gas in the streets, heating oil was also regarded as safer than natural gas. You rarely hear of a house burning down by a heating oil fire, it takes a lot of heat to vaporize fuel oil that is why its classified as noncombustible. On the other hand homes blowing up from natural gas leaks make the press quite often. Same with propane. Propane is heavier than air so it tends to pool in low spots and can build up. Natural gas is lighter than air, but in a closed house it just means a bigger boom if it goes over the LEL (5%) All three can be used safely but for some reason there are more short cuts taken with gas and propane installations and its lot easier not to notice a minor gas or propane leak.

My mom was deathly afraid of natural gas in a house. She did not even like it in the street as its not unknown for a natural gas leak in the street to follow an old pipe trench into a basement that had gas at one point but no longer had and cause an explosion.

The other aspect is similar to wood burners with respect to self reliance, a full tank of heating oil, several cords of wood or a ton or two of pellets in the basement is something you can depend on no matter how crazy the rest of the world is. Propane can have the same attribute but not a lot of folks have bulk tank, most rely on smaller tank filled frequently.
The safety aspect, or at least perceived is something I never thought of. Maybe because gas is so common here. It seems funny to me that I read about insurance companies not liking an oil tank in the basement but apparently they don't have a problem with gas. An excuse to raise the rates?

I do like the concept of self reliance with all the firewood I need for a winter and a 325 gallon LP tank for backup!
 
The safety aspect, or at least perceived is something I never thought of. Maybe because gas is so common here. It seems funny to me that I read about insurance companies not liking an oil tank in the basement but apparently they don't have a problem with gas. An excuse to raise the rates?

I do like the concept of self reliance with all the firewood I need for a winter and a 325 gallon LP tank for backup!
I suspect insurance companies have paid out way more $ because of leaky oil tanks over the years than anything NG related. They can make a huge mess, render a house a complete loss, and require very big $ environmental remediation.
 
Dont forget to compare apples to apples when figuring costs. A gallon of fuel oil(#2 diesel) roughly 140 ,000 btu. A gallon of propane roughly 92,000 btu. So take that $2.50 gallon propane and multiply it by 1.5. Also, I would not be surprised to see diesel start coming down. Crude oil in the mid 70's per barrel should not equal $5.50 fuel oil. Somebody in the middle is making a lot of money.
 
I suspect insurance companies have paid out way more $ because of leaky oil tanks over the years than anything NG related. They can make a huge mess, render a house a complete loss, and require very big $ environmental remediation.
Most of the regulations in Canada allow you to farm the contaminated dirt on the same property as it formed on.
If you do it yourself it is pretty cheap.
But as usual if you hire someone the regs they have to follow to remove the dirt and treat it at a different site makes it expensive.
My brother and I had to clean up government property that adjoined my Mom and Dad's old business.We had already cleaned up the titled property,but the goberment would not allow title change on the property till the road right of way was cleaned up.The cleanup was aprox 250 dump truck loads it took about 3 summers to farm the dirt.That involved turning it a couple times a summer.24 hour sunshine bakes the hydrocarbons out pretty fast
 
Hi all,

I'm wondering if anyone has ideas for how we can get kick our oil habit and the nasty storage tank (/potentially massive leak liability) that goes with it. House is ~2200 sqft including area of a finished basement, not super tight (~1945 construction, heavily built) but insulated during some house work and further by a Mass Save contractor. Our HVAC setup is as follows:
Supply:
-Oil boiler, rated for ~150 MBH hot water (but that's now massively oversized)
-MF Nova wood stove in main living room (rated for up to 50 MBH)
-Central A/C with outdoor compressor/condenser unit and air handler/evaporator in attic (don't know specs on system size offhand...)

Distribution:
-Hydronic baseboard radiators with two zones through the house for oil heat
-Ducted A/C system
-Indirect DHW sourced by oil boiler

Last year we used ~500 gallons oil for heat+DHW and between 2-3 cords of wood. Prior to wood stove install it was ~1000 gallons oil per year.

Any thoughts? Replace the A/C with a heat pump system (that is generally doable, right?) and transition to a wood pellet or cordwood boiler or propane for the coldest weather? Double up on heat pumps with one serving heat/cold to air handler and the other sending water to the baseboards?

Thanks!
Well, I'm pretty partial to my Froling boiler. I've been very happy with my choice but understand it might not be as economical now days given the price of everything... You will have to crunch the numbers for your budget but I would consider adding a Froling cord wood boiler onto your existing hydronic system. Keep the oil boiler as a backup and just tie into the controls and piping. The only downside to using a Froling boiler is you need space for the thermal storage tank. You're in MA so take to look at Solar Technics for unpressurized storage systems. Im in NY have have a 820 gal tank. With my baseboard emitters I have an effictive range in my tank of about 140/150 to 180F, so 30 to 40 degrees. I found the 820 gal tank used locally, otherwise if I was buying new I would of opted for the 1000 gal tank. My house is almost 2000 sqft ranch, 2 zones on the main floor, unfinished basement, domestic hot water. I use about 18 face cord a year and have to fire the boiler (5cuft firebox) 1-2 times a day. Typically one nearly full load a day when highs are near 32 or warmer. About 1/2 or 2/3 a load when highs are 32 or lower. Personally, I like hydronic heating better than forced air and if you are heating water with a boiler, there is little sense in connecting it to a forced air system when you already have a hydronic system installed.
 
Last thing I knew American Solar Technics is no longer making storage tanks and the business is for sale.

Bummer, as it was a real nice option, easy to install and took up far less space than any other tank ;)
 
Well, I'm pretty partial to my Froling boiler. I've been very happy with my choice but understand it might not be as economical now days given the price of everything... You will have to crunch the numbers for your budget but I would consider adding a Froling cord wood boiler onto your existing hydronic system. Keep the oil boiler as a backup and just tie into the controls and piping. The only downside to using a Froling boiler is you need space for the thermal storage tank. You're in MA so take to look at Solar Technics for unpressurized storage systems. Im in NY have have a 820 gal tank. With my baseboard emitters I have an effictive range in my tank of about 140/150 to 180F, so 30 to 40 degrees. I found the 820 gal tank used locally, otherwise if I was buying new I would of opted for the 1000 gal tank. My house is almost 2000 sqft ranch, 2 zones on the main floor, unfinished basement, domestic hot water. I use about 18 face cord a year and have to fire the boiler (5cuft firebox) 1-2 times a day. Typically one nearly full load a day when highs are near 32 or warmer. About 1/2 or 2/3 a load when highs are 32 or lower. Personally, I like hydronic heating better than forced air and if you are heating water with a boiler, there is little sense in connecting it to a forced air system when you already have a hydronic system installed.
Have you ever considered adding more emitters? Like, a bunch more of what you have now. Or some cast iron rads where you could? I seem to always be thinking about it but haven't plunged into it, yet, except for once a few years ago when I added a couple small sections of Slant Fin to cooler spots in my office. And my other half isn't exactly a fan of cast iron. But being able to lower your useful lowest supply water temp by another 20-30° is pretty big, like comparable to increasing storage volume by 50%+. My bottom now is in the 130/140 area. I usually don't charge past mid-170s.
 
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I have considered pulling all my slant fin and going with low temp emitters. I could almost double BTU storage capacity of my tank. It all comes down to cost/benefit ratio. The cost is steep and since my wood is "free" with just my labor and supplies I just keep coming down to I cannot justify the out of pocket cost especially now that I am retired. I only burn 3.5 to 4 cords a year.

Once I decide if I am keeping my house or building a new one, there are upgrades I would do to my existing house that would open up a couple of walls and have considered putting in radiant in the wall. For a new home its probably going to a net zero home so heating is going to be minimal.
 
I have cast iron rads through out my house, i can get heat out of storage down to about 110 F.
When it's -40 C/F i charge my storage to 185
I don't have any mixing valves for outside temps.
 
Last thing I knew American Solar Technics is no longer making storage tanks and the business is for sale.

Bummer, as it was a real nice option, easy to install and took up far less space than any other tank ;)
I did not know that, that's too bad. That was one of the primary reasons I built my system. Honestly, the only thing that is unique about their storage tanks is the liner material. With some galvanized sheet metal and some ridged foam board you could construct your own tank panels. Spray foam has some a long ways now days, it would be very easy to make your own tank. There is some engineering math involved to make your own drop in heat exchanger but it's very do-able. Sourcing the tank liner material is probably the biggest issue. I dont think its proprietary material but if you choose the wrong stuff then you might have a leak. I know he used more than one material over the life of his business.
Have you ever considered adding more emitters? Like, a bunch more of what you have now. Or some cast iron rads where you could? I seem to always be thinking about it but haven't plunged into it, yet, except for once a few years ago when I added a couple small sections of Slant Fin to cooler spots in my office. And my other half isn't exactly a fan of cast iron. But being able to lower your useful lowest supply water temp by another 20-30° is pretty big, like comparable to increasing storage volume by 50%+. My bottom now is in the 130/140 area. I usually don't charge past mid-170s.
Yes. I've given thought to replacing my normal emitters with the high efficiency ones but ROI seems low for the cost and labor. These were my first choice. Depending on the outside temperature and wind speed, the house starts to feel cool when the storage temp reaches about 150F (typically when outside temp is mid 20's). Using the chart they provide, Their emitter is capable of the same heat transfer rate at 115F as the traditional emitter at 150F. This would double my usable capacity (from 180 - 150, to 180-120). https://www.pmengineer.com/articles/91631-a-sampling-of-low-temperature-heat-emitters

I try not to charge my tank to 180 but it happens some times and I haven't noticed any illeffects. I try to keep it mid/upper 170's max. Some times I misjudge and load too much firewood. For a long time now I have been thinking I should adjust the "emergency" limit in the Froling controller to turn on the dump zone at 180 and just dump the heat in the house. I've been lazy though.
 
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