If you have pipes which are warm to the touch, which 'sweat', or go through unheated areas, the fix is quick, simple and very inexpensive. Simply snap the insulation over the pipe and run a strip of duct tape over the seam where pieces butt together. Cut short lengths of the foam insulation with a razor knife and bend around elbows and joints. While you're at it, insulate the cold water pipes too - this will keep them from freezing in unheated areas or during cold weather if you're away from home. If your home is heated by a central furnace, check the filters every month during winter.
Clogged filters reduce air flow and cause the furnace to work harder, using more energy.
Severely clogged filters can even lead to premature compressor damage. To check the filter, hold it up to a light and see if the light shines through. New filters cost about 50 cents each, and are simple to replace. Turn off electric power to furnace while inspecting filter. It's recommended that filters be replaced at least every three months of furnace use.