When I explain this, I use a car. If your engine dies, a mechanic can put in a brand new engine. That doesn't mean you no longer have a flat tire. The parts work together to make a car, but fixing one doesn't fix the others. It's the same with a doctor: your allergist isn't running an EKG on your heart.
What Won't a New System Fix?
- Your ductwork. The most efficient system in the world still gives disappointing results in some rooms if the ducts are too small, unbalanced or poorly laid out. See our zoning and balancing guide.
- The furnace you're keeping. Adding a heat pump or AC to an existing furnace doesn't change the furnace. Any problems it had, it still has.
- Floor-to-floor differences. In summer, the basement is almost always coolest, the main floor warmer and the top floor warmest. A new system doesn't change that unless you also add balancing or zoning.
- The sun. A room facing south or west that bakes in the afternoon sun will be warmer than a shaded room facing north or east, all else equal. Room size, windows and insulation matter too.
Will a New System Be Quieter?
- Outside, usually yes. Side-discharge heat pump outdoor units are almost always noticeably quieter than the AC units they replace.
- Inside, it depends. The new ultra-low NOx 80% furnaces aren't necessarily quieter than your old one; most are single-stage. Variable-speed blowers are quieter than multi-speed ones. High-end 97% modulating furnaces are usually quiet and smooth, and often don't cost much more than an ultra-low NOx 80%.
- Ductwork matters here too. Restrictive ducts make any system louder. A system that can breathe freely is quieter.
Will My Utility Bills Go Down?
- In summer, they may go up, if you didn't have AC before. A heat pump adds cooling, so you'll use more electricity. But you're no longer sweating through an 85-degree bedroom.
- In winter, it depends on gas and electric rates. Electric rates will go up; nobody knows by how much.
- With dual fuel, you can't really end up worse off. Say your old furnace costs you $100 a month. A new one that's about 5% more efficient brings that to about $95. That's as bad as it gets, because you still have a furnace. Then the heat pump can save you more on top of that.
- You can adjust it. If running the heat pump down to 20 °F saves you 10 to 15% above that temperature, set it there. If gas prices spike, move the switchover colder, say 5 °F, and lean on the heat pump. If electric rates jump, move it warmer. See how dual fuel works.
What Should I Fix Along With the New System?
That depends on your house. On our walkthrough, we look at your ductwork, returns, venting and electrical, and tell you honestly what will hold the new system back. Then you decide what's worth fixing now.
New System FAQ
Why Is One Room Still Hot After My New AC Was Installed?
Usually ductwork, return air or sun exposure, not the new equipment. Balancing or a better return often helps.
Will a Heat Pump Be Louder Than My Old AC?
Usually it's quieter. Most modern side-discharge outdoor units are noticeably quieter.
Will My Bills Go Up With a Heat Pump?
Summer bills may go up if you didn't have AC before. Winter bills depend on rates, and dual fuel lets you choose the cheaper fuel.