For a small home, what about using infrared space heaters as primary heat source? A fraction the cost of a ductless mini-split.
Julie Morse| Posted inEnergy Efficiency and Durabilityon
I live just north of Seattle and am remodeling a 1200 sq. ft home. I’ve had an energy audit done, and insulated and air sealed as much as was reasonable. But still it’s far from a well-insulated home primarily because of the cathedral ceilings and tongue-groove wood paneling (no air barrier) for a ceiling. I’ve spent 2 years trying to figure out the best way to heat. Currently I have a natural gas fireplace insert as the primary heat, but even with my creative use of fans it doesn’t circulate the heat throughout the house. Advise???
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Replies
Julie,
An "infrared space heater" is just another name for an ordinary electric resistance heater.
Electricity can certainly be used to heat a house, but in most areas of the country, it is an expensive fuel, especially if it is used to energize an electric-resistance heater. (Air-source heat pumps and ground-source heat pumps are more efficient ways to heat a house with electricity.)
If you have access to natural gas, you'll find that it is a less expensive fuel than electricity. However, I'm fairly sure that Seattle has relatively low electricity prices compared to the rest of the country, so you can heat your home with electric resistance heaters if you want.
Since you describe your house as leaky -- with a T&G board ceiling that lacks an air barrier -- I think that you will find that heating your home with electric resistance heaters is quite expensive.
Thanks Martin.
So would you recommend natural gas over electricity, even though a fireplace is far less efficient than a ductless heat pump?
Julie,
It doesn't make much sense to compare efficiencies between appliances that burn different fuels. For example, an electric resistance heater has an efficiency of 100%, while a high-quality gas furnace might have an efficiency of 93%. So what? That doesn't mean that it makes more sense to install an electric resistance heater than a gas furnace. After all, electricity is very expensive, and it many areas of the country, electricity is generated from coal-burning power plants which cause environmental damage.
A ductless minisplit might have an efficiency of 200% over the heating season, while a gas fireplace might have an efficiency of 60% or 70%. But as I said, you can't really compare efficiencies between appliances that burn different fuels.
To decide what fuel you prefer, you have to consider the overall cost of the fuel, the environmental effects of the fuel, and the cost of the equipment. It's your decision.
Julie / Martin,
I would consider two possibilities: 1. The first thing that springs to mind is hydronic radiant heat, with the heat source being an on-demand gas HW unit, or possibly with solar with on-demand back up. Radiant heat just doesn't go airborne, so you'd be able to keep in the 5'-6' zone where you live. Electric HW is only recommended if you are definitely going with solar.
2. With all your heat lofting its way up through the cathedral ceiling, I would think about a low-tech / low cost duct with in-line fan to de-stratify (reclaim) the heat and bring it back down to where you live. This would also reduce the stack effect and the delta T at the point of greatest heat loss. Distribution of the reclaimed warm air at floor level might be handled in the crawl space if there is one.
Best of Luck,
Joe
Julie, I think your question contains its own answer. Though you have insulated and air-sealed 'as much is reasonable' you have not tackled the ceilings which you have identified as both leaky and under-insulated. There are ways to address that problem and I'd suggest that's where you should spend any spare remodeling funds rather than on high-end mechanicals. Improving the enclosure at the ceiling level will almost certainly improve the room-to-room temperature gradient through the house, and supplementing your gas fireplace with electric baseboard units seems to make sense in a region where (as I understand it) electricity is cheap and mostly low-carbon.
A minisplit by itself of course will not solve your heat distribution problem unless it's a somewhat less efficient (and more expensive) ducted unit. And unless your cathedral ceilings are really high (20' or more) destratification arrangements such as Joe suggests will probably be of little value. Getting those ceilings tightened up should be your first priority!
Before you do anything with with mechanicals you need to fix the envelope. With the T&G cieling you are losing a lot of heat. I would say that is the starting point for any updapes.
I would assume the home was built with type of heating system, baseboard, elec or gas forced air. Many states have a low interest loan program that loans money for energy efficienct upgrades. With the help of the audit you should determine what upgrades are worth financing.
Agree that fixing the ceiling is smart, but I look at several a year and the conversation is always the same: do you want a new roof and bigger fascia boards, or do you want to move all your furniture, take down the ceiling, and then reinstall it (if it survives the demo process). You cannot convince the average homeowner that a job like that is worth the savings that it might achieve, even over a decade or two.
朱莉,mini-split投资。我们是我n the northwest where electricity is cheap (you are paying <10 cents per kwh, right?) and increasingly, natural gas is coming from hydro-fracking shale formations, a process which sure to go down in history as wretched mistake. up here san juan county, i can get small minisplit installed for ~$3500 then $1500 rebate bonneville power, screaming deal. you feel smug while getting your heat (mostly) hydropower wind.
If you can stand it, fix the ceiling too. Install some rigid foam right over it, and then drywall and paint it. It will make a major difference.