For college students living in a rental home, frugality tends to take precedent over comfort. So chances are, you or a few of your roommates are obstinantly refusing to touch the thermostat in favor of being bundled in blankets. Luckily, the DIY experts of Stack Exchange are here to help you stay warm this Winter by telling you how get the most out of your heating system for the least amount of money.

Question:

What are some DIY ways to increase the efficiency of a forced air heating system?

— Originally asked by Tester101

1: Hand-held Thermal Sensor

Look for cold spots in your home. A room that tends to stay cold, despite your attempts to keep it warm is a signal of trouble. A nice tool for all such problems is the hand-held thermal sensor you can now buy, like this Black and Decker Thermal leak detector. Just aim it at a spot on a wall, ceiling, etc., and click the button. It gives you the temperature. Now move the sensing spot around, and look for cold spots. This can tell you if you have missing insulation in a wall cavity, or a spot of cold air entry into your home. Use this to decide to add weather stripping to a window or door for example, or to inject foam insulation into a deficient wall cavity, or simply to help you balance warm air flow through your heating system.

— Answered by woodchips

2: Programmable Thermostat

Get a programmable thermostat if you don’t already have one.

They are cheap, easy to install, and setting it up to turn down the heat a few degrees when you aren’t home can make them easily pay for themselves in just a few months.

— Answered by Eric Petroelje

3: Replace Your Filter

The #1 easiest way—remember to change your filter.

— Answered by Eric Petroelje

4: Call A Pro

Neither DIY nor guaranteed to increase efficiency, but worth repeating:

Get your furnace cleaned and inspected by a professional.
They can tune your system and make sure you are burning at peak efficiency.

— Answered by yhw42

5: Dampers

Install dampers to direct air flow to the rooms that need it most. This will help if you find yourself raising the thermostat to heat a bedroom, addition, basement, etc.

— Answered by Steve Jackson

6: Clear Cold Air Returns

Keep your cold air returns unblocked, no rugs or furniture on top of them.

— Answered by SqlACID

7: Energy Audit

If you are willing to spend a little money, get an energy audit. It will tell you where you home’s biggest losses are, and point out many other places that could use a little work.

— Answered by Justin Love

8: Seal Electrical Boxes

Seal electrical boxes (usually light fixtures) in the attic, and use spray-foam on electrical conduit entrance holes.

— Answered by Justin Love

9: Next time you repaint…

Pull off the baseboards on outer walls and use spray foam to seal the wall-floor gap.

— Answered by Justin Love

10: Seal Your Ducts

Ensure all your ducts are properly sealed – you can use aluminum foil tape to wrap the joints and transitions. Don’t use regular “duct tape”, it will get brittle and become worthless pretty quickly.

Insulate all exposed supply ducting—there are many DIY products for insulating your ductwork.

— Answered by kkeilman

(via Stack Exchange DIY)