Best option for oil boiler replacement?
Live in a 4,500 sf old, inefficient house with 13+ people. Our heating system is an 80ish AFUE central oil hot water boiler with radiators. Hot water comes from a 75-gallon natural gas tank. We want to get rid of the oil boiler which cost us $3100 this past season. What are the most efficient, cost-effective, environmentally-friendly alternatives? Geothermal and biomass don’t seem feasible.
Our best solution so far is a condensing natural gas boiler. Since we’re doing that, we’re thinking of revamping the entire system by incorporating things like a combination boiler which does space heating and hot water (with or without an indirect storage tank?), solar thermal for additional hot water, and a drain water heat recovery system.
Is this a good plan or is this excessive? Are there better ideas?
Thanks!
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Replies
Karen,
Most energy experts predict that natural gas will remain a cheaper fuel than oil over the coming years, so if you have access to natural gas, that's the fuel to use.
You should also invest in an indirect water heater that operates off your boiler; such systems have very low operating costs compared to alternatives. A drainwater heat recovery device should yield a fairly fast payback, as long as people in your family prefer showers to baths. If your family prefers baths, don't get the drainwater heat recovery device.
Since you live in "an old, inefficient house," I'm sure that there are much better ways to invest any extra dollars you have than in a solar hot water system. Forget solar panels -- take that money and use it for air sealing and extra attic insulation.
Martin's advice is good, except for the "forget solar panels" part; but you should focus on air sealing and extra insulation. From a ROI perspective this is where you will get the biggest bang for your buck. A tighter house with a higher R value will burn less gas than your current inefficient one. But don't discount solar thermal as an option merely based on cost. If budget is an issue, you can phase this technology in incrementally over time. Ie: rough in the plumbing for a solar adjunct when your new system is plumbed in and add the panels and pumps at a later date when the money is there. This leaves you with options later on. Despite common nay saying, solar ROI is actually pretty good, relative to other renewables; but you should start with the basics. If your house is drafty and the insulation is weak, you're new boiler will be working harder than it needs to be. Invest in the envelop first and consider HRV, but don't count solar out.
Ditto insulation insulation insulation. Windows windows
Cheapest gallon of oil is the one you never burned.
Natural gas[not propane] is preferable to oil as the equipment and the fuel is cheaper. An indirect off of the boiler is a good idea. Also outdoor reset is saves fuel.
go to heatinghelp.com for more specific help
And no Dan does not pay me......
I suggest you get an energy audit; This will help identify and prioritize upgrades. There is an order that you want to do upgrades.
Thanks for all the comments. I already know to prioritize air-sealing and insulation. Believe me, they are on my to do list. If anyone has any other thoughts specific to the heating/hot water system, please share!
Karen
Are you thoroughly versed on sealing all the small air leaks (and some larger) in an attic. Do you know about attic bypasses.
Studies show tupgradingding equipment does alwayslwas lead to the expected energy savings. There is a lot of truth to the house as a system approach. Since we can't see into walls and homeowners do not typically have access to a thermal camera then how do you target weaknesses in a home. You might be interested in this http://homeenergypros.lbl.gov/video/infrared-at-work?xg_source=msg_mes_network
Does anyone know if central pellet boilers or hydronic ground-source heat pumps are feasible alternatives to a central oil boiler system with column radiators in Maryland?
I'd really like to get away from fossil fuels but these technologies don't seem available in my area. Is it worth waiting a few years before spending thousands of dollars on a high-efficiency gas boiler?
Karen,
You are asking many questions that don't have short answers.
Q. "Does anyone know if a central pellet boiler is a feasible alternative to a central oil boiler system with column radiators in Maryland?"
A. Yes, it is. A pellet boiler can replace an oil boiler. Do you have a steam system or a hot water system?
Q. "Does anyone know if a hydronic ground-source heat pump is a feasible alternative to a central oil boiler system with column radiators in Maryland?"
A. Yes, although a ground-source heat pump may require changes to your heat distribution system (replacement of the radiators with in-floor tubing or baseboard convection units).
Q. "Is it worth waiting a few years before spending thousands of dollars on a high-efficiency gas boiler?"
A. I don't understand your question. Do you mean that a gas boiler is your preferred system, and you are wondering whether gas boilers will improve significantly over the next few years? I'm not sure whether your question revolves around (a) whether your boiler needs to be replaced now or later (that depends on the condition of the boiler), or (b) whether investing thousands of dollars in a new heating system is wise (the answer is, it depends), or (c) whether it's better to wait for improved technology in the future (the answer is, it depends on the condition of your boiler and its efficiency, as well as the condition of your pocketbook).