As mentioned in a couple threads now, I'm starting to plan some bigger home repairs, with the only real goal being to reduce winter heating costs. The thing is, this is going to be a multi year project because I can't afford to do it all at once, and really really don't want to take on anymore debt until after the house is paid down a bit more or Dana's car is replaced.
In no particular order, here's the list of projects. What I'm trying to figure out is which projects would net the most energy savings to do them first.
- Replace central air unit with unit that has a heat pump
- Replace 25 year old 80% efficient oil boiler with something newer, be it a more modern "high efficiency(84-90%)" oil boiler or switching to gas and getting a propane tank (I'm still running numbers on this)
- Insulate the not insulated attic
- Replace the 12 foot by 7 foot windows in the living room with something more modern and better installed
- The house needs rewired anyway, so while the walls are down, better/new/any insulation added in
- Insulated vinyl siding to replace the stained, unknown aged, falling off in some places vinyl siding
- New roof, most likely metal.
With the exception of redoing the actual walls, those projects all cost about the same amount, which means I can afford to do one a year. The roof over most of the house is fine, so it's definitely on the lower priority list.
My thought was originally replace the AC next year, the boiler the year after, then do siding. That was before I found out the attic isn't really insulated. At the same time, I don't want to blow in a E36 M3 load of insulation and have it be in the way down the road when I rewire/remodel the house room by room. But heat rises and all that jazz.
So where would you spend the money first, or what on the list maybe isn't as helpful as other things for trapping heat in the house?
Keeping it cool in the summer would be a bonus, but isn't quite as important. AC only raises the electric bill $40-50/month, oil costs closer to $500/month and we need it longer throughout the year than AC.
Insulate that attic! It's not even close.
If there is no insulation in the attic, that's likely going to be your best bang for the buck (assuming that there are no leaks in the roof that would then soak the insulation). Wall insulation is good and important, but you're likely losing more heat through the attic than you do through the walls.
Is the oil furnace in dire need of replacement? If not and if it doesn't get stupidly cold where you are, I'd do the heatpump first. In our case that cut the heating cost from 450+ gallons of oil every 3-5 weeks down to 1-2 refills over winter.
I did talk to our HVAC guy and at least for us he seems to think that retaining the existing oil heat (albeit in our case, with one new furnace this year and likely the other one next year) is more cost effective than switching to propane. The math may be slightly different if you're already cooking with gas.
Duke
MegaDork
10/29/21 11:53 a.m.
Absolutely #1 priority is to get R-38 insulation in the attic as soon as possible. You are literally letting your money escape while trying to heat the world.
How is your attic configured? I wouldn't worry too much about future wiring - you can deal with that when the time comes.
If the boiler is reliably operational and 80% efficient I would table that until you solve some of the worse problems. Once you insulate the attic you may find that you don't need the supplementary heat pump to keep oil costs down.
Insulated vinyl siding is going to help minimally - somewhere around R-2 or R-3. I used it on my house but mostly because it helps hold the planks straight and flat, not for the R value. However, if it is in disrepair, I'd look into that earlier in the priority list to avoid any water leaks. You can also add 1/2" R-Max over the existing sheathing to pick up another R-3 or so.
No Time
SuperDork
10/29/21 11:55 a.m.
Insulation first, just like everyone has said so far, then windows (heavy curtains and draft stomping measures as a temp improvement) , then the boiler, then A/C.
High efficiency boilers only save money if they can modulate their output to extract as much heat as possible out of the fuel used. If they are running full throttle to overcome no insulation and window drafts, then they are no more efficient that what you have now.
Once you do the insulation, you may find the AC, boiler, or fuel conversion are not the big savings you initially calculated. At that point you re-evaluate the benefit and order of those items.
Attic has definitely bumped itself up priority wise. I'm sending Thing 1 up there when she gets home from school to pull some trash out and do some measuring to get an idea on how much insulation it's going to take.
Attic is big and open. Access through Thing 2s bedroom closet, it's about 4 feet high at the peak, and goes the whole way edge to edge. There are some vents as well. When I popped in the other day it was noticeably colder than the house or outside, like a good 10 degrees below ambient.
Not looking forward to it, but it does appear to be the lowest hanging fruit.
I feel like, and have nothing to base this on, that most of the radiators being on outside walls directly under windows isn't helping keep heat in the house either. I could be wrong, and Bob knows what it would take to move them to interior, but it seems like there are better options. At least around the kitchen, dining room, Thing 2s bedroom and the bathroom I have access to under the floor. I do wonder if it would be better if instead of using wall radiators I used under floor heating in those areas, but I have no idea what it would take to do such a thing or if the boiler could support it. That would be a lot of extra pipe to fill with water.
Duke
MegaDork
10/29/21 12:22 p.m.
In reply to RevRico :
Radiators are put there because the windows are a source of cold air infiltration. That's where they should be.
Tighter windows will help - if you can swing doing them at the same time as the siding, it will help logistically.
If future renovations include pulling down the ceiling under the attic, I would lay in 12" unfaced batts between the ceiling joists / rafters. They will be easier to deal with when you do that. If the ceiling will stay, then go the blow-in route.
Insulate #1 priority. We added 6-8" to the attic and the effect was noticable instantly. That fall we replaced the AC/Heat wih a new effcient heat pump that was more appropriately sized. Lastly we did the insulated siding. It wasn' as noticable, but on windy days (so, like 350 days a year) its much quieter. Our winter bill dropped from $500 to $300. Summer from $500 to $400. Those drops despite 2 years of increasing rates.
The bandaid option for leaky windows is the seasonal shrinkwrap plastic. It's not too expensive if you buy big sheets of it, and it can make a significant difference on old leaky windows until you get to fixing them.
In reply to Keith Tanner :
That's what I've been doing. The windows aren't really leaky, at least compared to the old house, but they are huge.
We have thermal blackout curtains on them, and the biggest one has a fancy blind curtain combination thing. I only really notice movement on really windy days, but still, 94 square feet of window is a big hole.
The curtains helped a lot this summer, this will be the first winter since we hung them. If only I could get someone to leave them the hell alone.
If I had to guess, they're from the late 80s, when it looks like the previous owner remodeled the last time. Single pane, custom sized.
Up and to the left slightly of Thing 2. I'd kicked around the idea of replacing them with a door and building a deck, but the driveway gets in the way.
No Time
SuperDork
10/29/21 1:22 p.m.
In reply to RevRico :
There are mullion kits available for some replacement windows and I had good luck using standard sized windows and the mullion kit to minimize cost and labor to upgrade while avoiding custom windows. (although that was 2004 ish using pella aluminum clad with wood frames and sashes).
No insulation may be a bit wrong. But whatever this powdered dirt looking stuff is is missing in a lot of places
Attic insulation, then windows, then wall insulation, then insulation of doors and floor.
Then, use the run-time and capacity of your furnace on the 5th coldest day of the year and air-conditioner on the 5th hottest to size your heat pump.
BoxheadTim said:
That insulation looks like vermiculite, which may or may not be bad news: https://www.epa.gov/asbestos/protect-your-family-asbestos-contaminated-vermiculite-insulation
Definitely have it checked out. Bad E36 M3.
Just outside of da 'burgh if I remember right. Lots of cheap asbestos used in houses there.
Watch your steam/water pipes to the radiators too, if they are insulated in white and it's old there could be more there.
In reply to preach (fs) :
The pipes are all not insulated. Some are painted with aluminum paint, but none of it is insulated. Another thing I want to fix, because it takes like 3 minutes to get hot water at the kitchen sink.
I would think you would want to do the windows and siding at the same time. I would imagine you would need to tear off quite a bit of siding to replace the windows, no sense in putting the old stuff back up if you're gonna replace it all anyway.
