Best expenditure of $$ to decrease home heating costs?

In My Humble Opinion
1

I live in a 1940s vintage house that has proven quite expensive to heat during winter, and as energy prices continue to rise this trend is likely to continue. So I’m willing to invest a few bucks to make my house cheaper to heat, on the assumption that this investment will pay for itself in some reasonably small number of years.

There are two obvious things I could do. First, replace the windows. My windows are old, single pane units, and the upper sashes on many of them are loose and refuse to stay put. Newer windows fit better and are better insulated, and of course as a side benefit will make my house look nicer.

The second option is to replace my furnace. My house has radiant heat provided by and oil furnace. To say my furnace is old would be an understatment. People look at my furnace, scratch their heads, and say things like “wow, ain’t never seen one of those outside of a textbook.” It may be original to the house. The house has a natural gas line, and a newer furnace would surely be more efficient, not to mention getting the 250 gallon tank out of my basement and never running dry.

Is there any way to make a quantitative assesment of which of these (or perhaps some other that I havn’t thought of) investments will yield a greater return in energy savings? I can (an will) of course, turn down the thermostat, but since I have small children at home the house is occupied pretty much 24/7, and radiant heating systems don’t lend themselves to digital controlers and daily temperature variations.

Any and all advice and/or suggestions would be greatly appreciated.

2

I’m probably simply restating what you know, but you will definitely save a bundle over a few years time replacing the oil with a nice efficient gas heater. On the other hand, you’ll never catch up while you’re heating the rest of the world through your poorly insulated windows, and probably the rest of the house. I can’t make the money calculation you’re requesting, but my hunch is that the money spent on insulation will come back to you quickly. That is, not only replacing the windows, but doing an evaluation of the building, and how and where it’s losing heat. Best way to do that informally, of course, is to see where it’s coldest. If you’re going to keep the old girl for a while, it may very well pay to have new insulation blown in. A truly well insulated building can hold its heat for a long time, keeping heating costs waaaaay down. xo, C.

3

“My windows are old, single pane units…”
You have storm windows too?

How’s the insulation in your attic? Heat rises.
I spent $70 putting some fiberglass batting in mine, and saved several hundred on heating the next winter.

4

We replaced both the furnace and put in new energy efficient windows in our circa 1760 colonial house. Before we did anything, our heating bill was about $900 a month in the winter. A new furnace dropped the bill down to about $750 - $800. Like you, we probably would have had to replace the furnace anyway ($5000) because it was so old. The savings were a bonus.

Then, we put in new energy efficient windows in the whole house ($15,000). The heating bill dropped to about $350 - $400 a month instantly.

The best bang for your buck will probably be the windows but both will be worthwhile. Expected payoff should be in the 4 - 6 year range.

5

Have you seen those do-it-yourself insulating kits with the clear plastic sheeting that goes over your existing window sills? You could try that this winter to see how the rooms feel with drafts and air leaks reduced. If you like the results, you’ll have a much better indication of whether replacing windows will be enough, whether you need to also replace the furnace, or increase the insulation in the ceiling or something else.

6

Do you have high ceilings? I shutter at the thought of doing this to an old house, but a drop ceiling would make the furnace’s job a bit easier as it would have a lot less space to heat.

7

Do you shudder too? (although shuttering is appropriate to this thread).:slight_smile:

Does your state offer tax incentives to put in energy-efficient appliances? My SO’s mother just had a natural gas furnace put in, and between the gas co rebates and the state tax rebates, she saved about $500.

8

If your home is empty of people (pets seem more adaptable) then a programable setback thermostat is a really cheap way to save substantial amounts of fuel…the worse your insualation, the more the payoff.

9

If it’s as I think you describe it, and it sounds like you are budgeting your money, there is one prudent course of action. Take out a home improvement loan and replace the furnace, get new double-pane windows and make sure the house is well insulated. (The cost of the programable thermostat is minimal but worth it.) The energy savings will probably make the loan payments and leave some money left over. Bite the bullet and get the place in order. It will prove to be a smart decision. It will also add value to the house so you will probably recover all of the costs at resale.

Modern furnaces are so much more efficient than the old stuff that there is no comparison. With a big old house you want to get something good so don’t nickle and dime it. Same for the windows. There is a big difference between cheap windows and quality. If you buy cheapies you will regret it. Trust me on that. Get the good stuff!

10

The very first thing you should do, even before you replace windows or add insulation or anything, is go around your house and seal all the cracks and holes where air infiltrates.

This is a low-cost step that will yield a lot of results for the buck. When I was in architecture school, we learned that the average North American house has sufficient cracks and air leaks that it has the equivalent of a hole roughly six decimetres (two feet) square in one wall. The result was that the average room was having its air changed about once an hour. When it’s -20 out, the cost of heating all those roomfuls of air, over and over again, adds up.

Once the house is sealed, you then add a purpose-built air exchanger. This can be designed so that outgoing warm stale air heats incoming cool fresh air. Often air exchangers are built in as part of the heating system, especially with foprced-air heating.

The next thing I’d do is replace the windows with dual or triple-glazed units.

Only then would I move to larger steps like insulating the house as much as I could and replacing the furnace.

There are additional things that can be done to reduce the need for a heat source, but the more efficient the house is, the more it has to be designed and built that way, and the harder it is to retrofit an existing house to work that way.

You can add ‘thermal mass’ to the interior of the house, inside the insulation. Once this is brought to room temperature, it will warm a roomful of air without becoming much colder itself. Pair the thermal mass with big sun-facing windows: the sun will heat the mass for free, and the mass will heat the room.

I have friends who live in such a house near Bancroft, Ontario. Thay live in an area where winter temperatures drop to -35 or -40 Celsius, and they need no furnace. The house never drops below about 15C, even if they go away for a month.

11

:: rereads OP ::

Another suggestion before you replace the windows: thick insulated curtains. Seriously. Install them so that they touch the windowframes, and close them at night. You will lose a lot less heat.

An alternative mught be insulated shutters that fit the interior of each windowframe.

A couple of random links.

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Wear a really thick coat indoors? ($50)

13

What’s a thermal mass? A Newfoundland?

Anyway, I’ve heard it said (no cite, unfortunately) that insulating the attic is dramatically more effective than replacing windows – I suppose because heat rises. I suspect your attic already has insulation, but you could thicken the layer.

14

Keep in mind when adding insulation that it’s really easy - R values are cumulative, so even if you have old tired out loose insulation in the attic or something you can just lay down some new stuff on top of it and voila, better insulation. (Unless there’s other problems in your attic, of course.) I just moved into a house built in 1928, and what had been a laundry porch when it was built had been enclosed sometime in the meantime but without being insulated from below. A couple rolls of the Pink Panther stuff and you can definately feel a difference in there! It’s super cheap and you really do feel a difference.

15

First thing is to call up your local utilities – electric and gas – and ask if they can do an energy audit of your house. In most places, the utilities have programs to go out and look at a customer’s house and make recommendations on energy savings. These are free to the customer.

Typically, they’ll give you a ranked list of improvements to make (e.g. 1. Insulate ceiling – payback 1.3 years / 2. Replace windows – payback 2.1 years, etc. etc.).
Which I think would answer your OP and maybe point out some things you didn’t think of.

16

Switching to a natural gas furnace may not solve any problems, given the expected skyrocketing cost of natural gas. Baltimore Gas & Electric is predicting a 25-33% increase in prices. In a recent press release, they give a number of tips to save money and energy, including cleaning filters, vents, and chimneys.

17

Sorry. I should have explained more… I’m so used to this stuff that I sometimes forget how unfamiliar it can be to others.

Anyway, a ‘thermal mass’ is simply a mass of something heavy, like brick or concrete or stone or earth, placed inside the insulated volume of the house, so that it can store heat. Usually it is included as part of the walls or floor of the house, but I have seen mention of a brick veneer added inside regular wood-frame walls later as a retrofit.

18

Moved to IMHO.

-xash
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