Installing a programmable thermostat

My apartment has an antiquarian furnace, and I'm doing what I can to squeeze energy savings from it this winter. Earlier this month I replaced the furnace filter. My latest project was to install a programmable thermostat.

It's a simple way to eke out energy savings, particularly in northern climates. The idea is that you'll set the program to lower the temperature when you're asleep in your cozy bed at night, or out at work during the day. The savings at night are the more significant, and in an older house like mine, will probably equal about 1.8 percent for every degree celcius I drop the temperature.

So, if I drop from 20C to 16C at night, I should be looking at savings in the neighbourhood of just over 7 percent. The savings will vary depending on insulation and climate, and the scenario is different for people with heat pumps. But I expect a lot of renters are in my situation -- old, poorly insulated house with a big ol' gas or oil furnace. For more information, there's an interesting paper here by Andre Plourde, a professor at the University of Alberta.

A basic programmable thermostat costs about $30, though you can pay plenty more if you want something fancier. I bought mine when a $15 rebate coupon came with my Enbridge gas bill. So really, I'm out about 15 bucks for the thing, and should easily recoup the cost. And it looks a lot nicer than the old mercury thermostat.


How to install a programmable thermostat
This is surprisingly easy. Most older furnaces have a simple two-wire system and the wires are usually colour coded. Read the instructions that come with your new thermostat.

The first step is to slip off the cover plate of the old thermostat. It just slides off with a simple tug.

Notice the bubble of silvery liquid at the top. That's a glass tube filled with mercury. This is a hazardous material, so remove the thermostat with care and follow instructions from your municipality regarding proper disposal. In my city, one can bring them to a Community Environment Day or bring it to one of the city's hazardous waste depots.

After removing the cover, remove the screws holding the thermostat to the wall. These will probably be small flathead screws. Then unscrew the two wires from the terminal. Be careful not to let the tips of the wires touch. You may want to wrap them in electrical tape while you work.

Next, follow the instructions for mounting the new thermostat. On a two-wire system, each wire should be colour coded and easily screw into an appropriate terminal on the new thermostat. Then slide the face into place as per the manufacturer's instructions.

Programming the thermostat
My thermostat has four settings for weekdays and two for weekends. The idea is that you'll set it to lower the temperature when you go to bed, raise it just before you get up, drop it again when you go to work, and make the house toasty for your return home. On weekends, it's a simpler program to drop the temperature when you go to bed and raise it when you get up.

In my house, it's set for 16C overnight and 19C during the day, though I sometimes go up an extra degree first thing in the morning. I don't set it much lower during the day because I work from home (a simple two-program thermostat would have done me fine, but I couldn't find one).

Best of all, the new thermostat looks a lot nicer than the grotty old one. Being green is important, but aesthetics still count for something.

Furnace Filters

Replacing a furnace filter is, in most cases, very easy and very rewarding. It will improve the furnace's energy efficiency and improve indoor air quality.

I say "in most cases" because, well, some jobs are easier than others. Most furnaces have filters that come mounted in a handy cardboard frame. Here's an example of one, in case you haven't seen them before. Manufacturers suggest changing furnace filters monthly during the winter, and most are cheap enough that this isn't an unreasonable request. For these furnaces, you just slide the old filter out, note its size, go to the hardware store to buy a new one and then slide it in. Easy-peasey.

But not mine. Oh, no, nothing so simple for the Green Tenant. The furnace in my apartment was installed in 1984 and doesn't have the handy pre-framed filter.

For mine, one must buy a roll of fibreglass material and cut it to size. Still, it's not hard.

First, open the bottom compartment of the furnace (usually they just slide into place) to reveal the filter chamber. Then remove the carriage holding the filter. In this case, it was a simple matter of pulling the top edges in slightly, then sliding it out.



The filter on this model is held by clips on either side. They clip onto the mesh and are released by sliding (on this one, one side goes up, the other goes down). Then peel off the old filter. This one obviously hasn't been replaced in ages. Eeew.







Lay the old filter on the floor. Lay the sheet of new material over top, then cut it to size with an Olfa knife, box cutter or scissors.








Clip the new filter into the carriage, then slide the unit back into place. Follow any directions on the package (it might tell you which side of the filter to position facing in).







This won't make a 24-year-old furnace particularly energy efficient, but it will help the fan circulate warm air more easily. And your lungs will thank you, too.

Autumn checklist

Winter is coming, and in Canada that means there's lots to do. I've got a long list of indoor projects to keep me busy in coming months, but some need to be done before the first frost. For now, I'll put aside my gardening projects (though they will be the focus this weekend). What do I need to do in order to keep my apartment cozy and my gas bills low this winter?

1. Replace the furnace filter.
The furnace is frighteningly 24 years old. The thought of how much gas it'll use scares me. But replacing the filter will make it run more efficiently and help with indoor air quality. This furnace uses a different kind of filter from the previous furnaces I've had, so expect a post on it in the near future.

2. Buy heavy, insulating curtains for the windows.
Even good windows let a lot of heat out at night. At best, they're R8, which is nothing when you consider that even a 2x4 stud wall holds R14 insulation (and new construction here typically has 2x6 stud walls with R20 fibreglass and often an inch or two of rigid foam at R6-8 per inch on the outside for the newest homes). Good, thick curtains can make a huge difference. Close them at night to keep the heat in, open them during the day (especially on south-facing windows) to reap the benefits of passive solar heating.

3. Do something about the front window.
The front window of my apartment is north-facing. The main panel is double-glazed, which is good. The lower, opening portion, however, has two single-glazed layers. Not terrible, but not great, and likely draughty. But my main concern is a beautiful stained-glass panel at the top. This will let a tremendous amount of heat out. Curtains are a good start, but not enough here.

I'll throw this last one out to any experts who read Green Tenant. I know that I could use a heat-shrinking plastic film. But what are my other options? I'm a tenant, so not in a position to replace the window. And I like the stained glass. It's pretty. Any great ideas out there?