Overall message: Intellectually, efficiency is a great reason to upgrade a furnace, but comfort is the reason that we live with. It's an intangible, but valuable, benefit of replacement.
Comfort includes health factors: Clean air, optimum humidity.
Comfort comes from a more constant temperature and humidity level, which a higher efficiency model can provide (image: 2stage).
Not just upgrading from an obviously outdated model (image: gravfurn2), but even from an 80% efficiency unit (image: shop2) to a 95% efficiency unit (IMG_9328.26511848_std) has comfort and economic benefits (image: 95afue).
The comfort factor includes peace of mind with warranties.
Questions to ask when considering a Furnace Upgrade
Depends on unit.
How long to install?
Usually one day involves removing the old unit and replacement with new.
How to pick a furnace?
Get advice on sizing, etc.
Estimates should include: