It's the middle of the heating season - how well is your furnace "breathing" through the filter? Have you been changing the filter regularly? If not, January is a great month to start a regular maintenance cycle. Furnace filters should be changed every 3 months for optimal performance of the furnace. A clean filter allows better air flow and a furnace that doesn't have to work as hard to meet the heating demands of your house.
Check out these other posts from Jovag Home Inspection for further information on furnace systems and maintenance.
Brian Jovag, owner of Jovag Home Inspection.