[redpoint5]

I bought a 4 bedroom house 3 years ago and rented out the extra rooms. Now that I'm married, we only use 1 of the bedrooms. I have closed the heating vents to the 3 unused rooms and unused bathroom. In total, almost half of the vents in the house are closed. Would this cause excessive pressure on the ducting and place an unacceptably large strain on the blower motor?

In addition to closing the vents, I was thinking about taping over them so they don't even blow a small amount of warm air. Then I was thinking I would stuff a towel under the door gap to isolate the rooms from the rest of the house. Could this save any noticeable amount? The bedrooms are all on exterior walls.

Of course, I have a highly programmable thermostat set to suit our daily schedule, and we turn off the heat when we leave anyhow.

With an unusually low temp of 16 deg F, I've been thinking about this more recently. Hopefully the fuel in the truck doesn't gel, otherwise it will be a cold commute on the motorcycle.