Cost of Oil vs Propane vs Something Else?

brandon15

I live in eastern PA in a 3,000 sqft stone farmhouse. Half of it is original (no insulation just 18" thick stone walls), the other half was just built in 2021 with good insulation and windows. I have an 25+ year old oil boiler, with a mix of cast iron radiators, new hydronic baseboard, and new hydronic radiant floors.

In winter months, we go thru a tank of oil a month (275 gallon tank), so I also installed an outdoor wood boiler. I love my OWB, oil boiler barely runs now, but with my young family of 3 kids, time is sparse to split all the wood I need to run my OWB (8 cords a winter). Wood heat is free, my time is not. Wanting to balance cost vs time savings.

All that to say, would switching to a different fuel save anything? A propane boiler vs oil. Or perhaps another alternative? Would love to hear opinions.

pecmsg

NO

Tightening the envelope WILL save money. 

Jamie Hall

Assuming that you don't have natural gas available, oil and propane really are your only two choices (some might suggest looking at an air to water heat pump, but without major tightening of the envelope it's not likely to really do the job in colder weather). The cost of a BTU of heat from oil and a BTU of heat from propane varies widely. What you need to do is to find your local cost of a gallon of oil -- which contains about 140,000 BTU -- and a gallon of propane, which contains about 90,000 BTU p- and compare the relative costs.

It's likely that you will find that they are comparable -- in which case switching would be a waste of money. The propane would have to be a LOT cheaper to offset the cost of the switch.

brandon15

pecmsg said:

NO

Tightening the envelope WILL save money. 

Definitely, easier said than done in an c. 1800's stone farmhouse. We recently remodeled our kitchen, which is in the original part of the house, and added 2x4 walls with spray foam, new windows and a new exterior door. Ideally would do this to each room in the old part of the house. Maybe if I stumble upon some $$$.

hot_rod

If you have X amount of dollars to spend, spend it on upgrading the building. Seal cracks, upgrade insulation, window coverings, etc. That is better money spent compared to switching fuels.
You already have a dual fuel system with the wood burner.

Are the kids able to help with the wood ritual? If they get cold enough they will

There may be energy audit or upgrade programs from your utility, www.dsireusa.org lists the programs.

A blower door test would tell a lot about your building, infiltration, drafts are huge energy stealers.

I wouldn't say wood is free as an energy source. It needs to get from the tree to the firebox, certainly some fuel and time involved.

WMno57

I have an out of the box idea for your home.
Use the thermal mass of the stone as a thermal storage battery. Recharge the stone battery at night with low time of use electric rates and an air to water heat pump.
It would involve extensive remodeling of the old section of your home. The stone walls would become the interior walls. Does your wife like the rustic look? Moving outwards there would be some type of hydronic system. Shotcrete and pex????. Then a bunch of fiberglass insulation, vapor barrier, and on the exterior, new siding of your choice.
No idea if the cost of all this would make financial sense. It would be cool though. Maybe you could sell tours to the green dreamers.
General Motors has the Ultium battery.
You could have the Flintstonium battery!

hot_rod

also a good cleaning and tune on the oil boiler could save some oil consumption 

Hot_water_fan

Do what @Jamie Hall says to compare costs. 

What you’re getting at is hedging fuel costs - there are many ways to do it, switching fuels and/or adding insulation are two options. You might also just invest in oil company stock, it’s a bit easier to transact than home improvements. 

WMno57

Jamie Hall said:

oil -- which contains about 140,000 BTU

129,500 BTUs per gallon for Number two 100 percent Dinosaur Syrup.
127,250 BTUs per gallon for B20.
https://en.wikipedia.org/wiki/Gasoline_gallon_equivalent#Gasoline_gallon_equivalent_tables

Jamie Hall

A useful table:
https://ipm.cahnr.uconn.edu/heating-value-fuels/
Note that #2 heating oil is 138,500 BTU per gallon.

It also happily includes values for quite a range of other fuels...

WMno57

Home heating oil has more BTUs because it is made from carnivorous dinosaurs. On-road Diesel is made from vegan dinosaurs.
Kidding. I got no idea why such a big difference in published BTUs. I have heard that most refiners make one type of #2, then add red dye for off-road and HHO. In the USA today almost all if not all HHO is Ultra Low Sulfer (under 15 ppm). I did read that California requires a higher Cetane Number. I'm not sure if that could make such a large difference in BTUs.
More research is required.

brandon15

WMno57 said:

I have an out of the box idea for your home. Use the thermal mass of the stone as a thermal storage battery. Recharge the stone battery at night with low time of use electric rates and an air to water heat pump. It would involve extensive remodeling of the old section of your home. The stone walls would become the interior walls. Does your wife like the rustic look? Moving outwards there would be some type of hydronic system. Shotcrete and pex????. Then a bunch of fiberglass insulation, vapor barrier, and on the exterior, new siding of your choice. No idea if the cost of all this would make financial sense. It would be cool though. Maybe you could sell tours to the green dreamers. General Motors has the Ultium battery. You could have the Flintstonium battery!

I’m all for outside of the box ideas! Radiant walls are actually popular in Europe, according by to things I’ve read. To retrofit into a stone house, it would be quite a bit of work! 

I’ve also had the thought of going to an electric boiler and running it off of solar.

WMno57

Solar gives you watts during the day. Largest demand for heat is at night and early morning. You could have two boilers, electric during the day and oil at night.
I like @hot_rods boiler tune up idea best. Does Energy Kinetics have a condensing oil boiler? @EzzyT recently posted a very nice EK gas mod-con install. Really hard to show a Return on Investment payback on any new equipment or major construction. But if you need a new boiler anyways................

brandon15

WMno57 said:

Solar gives you watts during the day. Largest demand for heat is at night and early morning. You could have two boilers electric during the day and oil at night. I like @hot_rods boiler tune up idea best. Does Energy Kinetics have a condensing oil boiler? @EzzyT recently posted a very nice EK gas mod-con install. Really hard to show a Return on Investment payback on any new equipment or major construction. But if you need a new boiler anyways................

I’ll have to check those out never heard of them. The solar idea would be a bigger project, because while I’m at it I might as well get enough panels to do the whole house, install batteries that get charged during day and give you power over night. 

I also contacted a local alternate heating supply company that makes a supposedly very efficient inside wood boiler that has an oil backup. I like my owb because the mess is outside and I can throw larger logs in. But I go through about 8-10 cords a year depending on how cold and how long I run it. If the interior wood boiler was way more efficient and cut down on amount of wood, it wouldn’t be a bad option. My property is mostly forest and I have tree companies dropping off, so wood is endless. 

Hot_water_fan

It depends on your electricity prices of course, but a heat pump could be cheaper and provide AC, if you don’t already have that. Keep the oil and the wood in that situation and have a triple option heater. If you already have ductwork for AC and that AC is getting up there, then a heat pump  could be your cheapest installed option by far. 

Jamie Hall

Heat powered by solar? Even if you can use a heat pump --which is at best maybe -- you are going to need a VERY big array, and a lot of battery -- or kid yourself into thinking it's solar when really it's still the grid.

But let's just crunch a number here...

Suppose your heat loss is 68,000 BTUh, which is about 20 KW. There are two ways to go:: if we assume an electric boiler, that's the power you need. If we assume a heat pump and are generous and say on that cold night it can manage a COP of 2.5, that's 8 KW. Now further let us suppose that you are in the northeast somewhere. The useful insolation in the northeast does vary, but a sort of back of envelope number is an average of 3 hours per day, with as many as 3 consecutive days with no usable sun in the winter. OKJ. Let's use the heat pump, since it is the more optimistic. We need to receive from the suand and store a power output of 8 KW for 3 days. 576 KW-hours of energy. A Tesla PowerWall, for example, stores 13.5 KW-hours of energy, so you'll need 43 of them. Then you need to charge them. A good modern solar panel with good orientation can be expected to produce around 250 watts per square meter of panel. You'll need to charge your batteries in a time span of 3 hous between blizzards, so you'll need about 10,000 square feet -- a quarter acre -- of solar array.

Still game?

Hot_water_fan

Ha @Jamie Hall you’re right obviously, but nearly every solar install is grid connected. 

brandon15

Hot_water_fan said:

It depends on your electricity prices of course, but a heat pump could be cheaper and provide AC, if you don’t already have that. Keep the oil and the wood in that situation and have a triple option heater. If you already have ductwork for AC and that AC is getting up there, then a heat pump  could be your cheapest installed option by far. 

Thought about that too. I do have ac ductwork. It’s getting up there in age but still runs like a champ. Will definitely consider when it’s time to replace. That could at least be an option for the more mild winter months

Hot_water_fan

Thought about that too. I do have ac ductwork. It’s getting up there in age but still runs like a champ. Will definitely consider when it’s time to replace. That could at least be an option for the more mild winter months

I’m in a similar climate and use it all winter. Works out to be cheaper than natural gas here, but of course it’s utility dependent. It’s essentially free to install!

brandon15

Jamie Hall said:

Heat powered by solar? Even if you can use a heat pump --which is at best maybe -- you are going to need a VERY big array, and a lot of battery -- or kid yourself into thinking it's solar when really it's still the grid. But let's just crunch a number here... Suppose your heat loss is 68,000 BTUh, which is about 20 KW. There are two ways to go:: if we assume an electric boiler, that's the power you need. If we assume a heat pump and are generous and say on that cold night it can manage a COP of 2.5, that's 8 KW. Now further let us suppose that you are in the northeast somewhere. The useful insolation in the northeast does vary, but a sort of back of envelope number is an average of 3 hours per day, with as many as 3 consecutive days with no usable sun in the winter. OKJ. Let's use the heat pump, since it is the more optimistic. We need to receive from the suand and store a power output of 8 KW for 3 days. 576 KW-hours of energy. A Tesla PowerWall, for example, stores 13.5 KW-hours of energy, so you'll need 43 of them. Then you need to charge them. A good modern solar panel with good orientation can be expected to produce around 250 watts per square meter of panel. You'll need to charge your batteries in a time span of 3 hous between blizzards, so you'll need about 10,000 square feet -- a quarter acre -- of solar array. Still game?

Dang dude leave some knowledge for the rest of us!! Haha thank you for breaking it down though. 

I more meant that I could end up going solar for the whole house, would pull from the grid some months, other months would have surplus and hopefully break even at the end of the year. 

hot_rod

Most solar PV is grid tied these days, so the grid is a storage device. Some days you bank solar, other days you pull 100% from the grid

Check what your local utility grid  for  off peak rates for residential. Also what they credit you for feed in.

There are plenty of online  solar PV calculators to show you the numbers both power generation and financials

Most of the outdoor furnaces are about 40% efficient when burning large, green wood.

Higher efficiency gasification types can run into the 80%. So 1/2 the wood consumption.
They require dry wood to burn cleanly, wood stored for a year or two so more wood work😉

I doubt you would recoup the cost of a dual fuel gasification wood boiler and the thermal storage tank they typically require. Same  with a large enough PV array

If you have duct work an air to air heat pump may be the best least expensive backup for the wood  fired unit  you have, heat and cool at the lowest possible cost. That give you wood, oil or electrical fuel options.

So many homeowners have gone through this exercise here at HH over the years. You can do some number crunching and get close approximations, fickle mother nature has the final say on what it will cost to heat and cool a home

Dave Carpentier

Is the time factor with the wood more of the pre-season prep time , or the daily handling ?

Paying a crew of laborers to cut and stack the 8 cords would have a cost of course, but otherwise mainly free btu.

hot_rod

It depends on how well you process the wood. To get a good dry piece of cord wood you want no splits larger than 6” across. So you can get the wood dried completely. This is what the Wood Resources lab claims. This is pretty important for gasification type burners, else you end up cleaning the fire tubes inside, often.
I had a covered shed that got a lot of sun, so 1 year was enough to dry wood.

I sharpened my saw ever trip put as I cut mainly hardwoods. It’s less work on you and the saw to have it razor sharp. I kept an extra chain in case you hit the ground or a old nail inside the tree😗
Mixed gas, bar oil, fuel cost for the truck or 🚜 Cleaning the stove and brushing the flue monthly, ash removal,etc all burn up time and $$

Unless you get up once in the night it is tough to get an 8 hr burn. So then you have the whole fire starting procedure again. By design gasification boilers do not have a large firebox. Often they are put inside the home so they are built to fit thru doorways. The 40kw and smaller residential units anyways.

When you buy wood split, delivered and stacked, they price it a few bucks below LP in my area. So it only work out if you process you own. At least in my neck of the woods

Jon_blaney

The cost of cut/split firewood is going to be cheaper than oil. If you do not have the time, pay to have it done. Maybe you are living in the wrong house.

MaxMercy

I'm in CT, and oil is way cheaper than propane where I am (and cheaper than NG), but your area may differ. You can check with people around you (there might be on-line current day prices) and compare the price per gallon being aware of course that propane has a lot less BTU per gallon, and you may have to rent the tank.

Even with stone walls, a lot of heat is lost through windows, doors, general leaks, *and* the roof. Don't overlook your insulation above the ceilings.

EDIT: I just checked this mornings prices. In Connecticut, oil is $3.30 and propane is $3.79 per gallon. Considering how much less BTU propane has compared to #2, it's a LOT more expensive.

leonz

Since you live in eastern Pennsylvania near the anthracite coal mines you should seriously look at using Anthracite Coal for heating you home and hot water using a coal stoker.

You will save a great deal of time and money if you use a coal stoker boiler to heat your home and domestic hot water.

The only ones I would recommend are the Axeman-Anderson 130S or 260S with the domestic coil, the EFM DF520 with a domestic hot water coil and the AHS S130 or S260 with a domestic hot water coil.

These three coal stoker boiler brands are made in Pennsylvania, The Axeman Anderson coal stoker 130S and the 260S are made in South Williamsport, Pa. and the EFM DF520 coal stoker boiler and AHS Coal stoker boilers are made in Schukyl Haven Pa.

I have a coal stoker boiler with a domestic hot water coil and I have not heated my home with oil since 2015.