Oil heated baseboard vs Mini split system?
digdug18
| Posted in Energy, Heating & Insulation on
I currently live outside of philadelphia, in a 2000sq ft single story home, with basement. I have oil heat, hydronic baseboard currently. My oil heater was new in 1970, and is now about 60% effecient according to 2 different effeciency tests. I am considering installing 3 mini-split ductless blowers in 3 of the rooms/living spaces, for supplemental heat and cooling.
I want to save money on my heating, my insulation will be upgraded in the spring, I’m adding slow rise foam in the walls, and 8 inches of cellulose in the attic, a new whole house fan with automatic shutter mechanism, as well as a new attic staircase that self seals.
Thoughts please!
Andrew
Replies
The mini-split systems have ... electric heat? Or is it a heat pump? Electric resistance heat will be more expensive ... normally ... depending on the cost of oil and the cost of electric, but normally electric resistance dominates the cost of energy.
On the other hand, your furnace is like 40 yrs old. Maybe consider a switch to a new more efficient option w/ cooling option, too. You could get a gas option (assuming it is available) in either a moderate efficiency (i.e. 80-85%) or a condensing style (90+% efficient).
A couple of mini splits may cost as much as a new furnace ... not sure, but I'm guessing they may be a bit expensive.
By far
the best things you can do are insulation and air sealing.
Re oil vs mini-split, to compare operating costs, you need to know the cost per BTU delivered from each fuel. You also need to factor in equipment cost and your expected time period of ownership/use.
What does a gallon of oil cost you, and what is electric per KwH?
Gas heat isn't an option, doesn't go down my street or any in a 5 mile or so radius, everyone around me either uses oil or electric baseboard.
The mini-split's i'm looking at have both a heat pump, and resistance coil, you can decide when and if to turn the coil on.
I might still get the mini-split system, to use in the 9 months of the year we aren't below 30f, as it would be much more effieicient then.
Andrew
For your application,
mini-splits make a lot of sense. As does all the insulation retrofitting. However, I would also investigate making the attic part of the conditioned space (i.e. hot roofing) instead of the attic fan business. That way you can skip the soffit vents, ridge vents, and all the other lovely ways to increase infil/exfiltration from your home. See buildingscience.com for more info on the benefits of a hot roof. We love ours - zero issues!
I would also consider getting a right-sized oil/propane boiler as a replacement. I am a fan of direct vent solutions (more common with propane) since they limit infiltration also. Plus, if the masonary chimney is then no longer needed, you can demo it and use its former space for your whole-house fan cooling solution.
Guessing game
Costing the fuels cost is a bit of a guessing game at present.
I'm readign that heating oil cost could more than triple over the next decade. Some, sources are predicting electric costs to double in some areas.
Adding insulation and getting things more air tight are the only sure bets.
Thoughts
Although your oil-fired boiler probably has decades of life in it yet, look at replacing it with a unit sized to accomodate your house WITH the improvements.
Chances are the boiler will be half the size (literally and capacity-wise) and you could more likely afford a much better, very efficient oil burner.
You have no central cooling now?
Mini-split Heat Pumps are a reasonable way to add cooling in houses with no duct work. In PA, air cooled heat pumps could provide a fair amount of the heat required in the sprinng and fall. This would save you from firing the boiler for an early or late cold snap.