Re: Choosing a new furnace
Sealing the ductwork that's in unheated areas would be a good thing to do, too. There can be an incredible amount of energy loss due to air blowing out of the joints. The preferred material is duct mastic. Second option is foil duct-sealing tape.
Do not use duct tape. It may have originally been designed with ducts in mind, but the adhesive dries out and it falls off when used on a duct. Most code inspectors would probably say "harumph" if they saw it on your ducts. Save that stuff for making wallets, shopping bags, holding your car bumper on... anything that's not critical or expected to last a long time.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.