Monica Parisi is making big changes to her East Davis home that promise benefits to her and the environment. First things first: so, in 2015 she installed solar panels, which set a strong foundation for an all-electric home. Rooftop solar gives Monica access to inexpensive power, which makes transitioning from gas to electric more affordable and feasible. Smart move. Now, what should she do next?

When’s the right time to replace air conditioners and furnaces?

The federal EPA has developed a recommendation on how long to stick with those old appliances before moving to a more energy efficient, cleaner alternative. They consider a number of factors, among them the energy embodied in the appliance at the time of manufacture. If you buy a new appliance too early, you essentially waste that input. On the other hand, if you wait too long, you may be using an out-of-date energy hog.

Replacing older systems with new models generally saves money in energy costs and reduced emissions.  The sweet spot for an air conditioner, according to the EPA, is 10 years. For a furnace, 15 years. Likely your appliances will last longer than this, but this is the point at which upgrading to more efficient equipment makes monetary and environmental sense.

The EPA seems to assume that a gas furnace will be replaced with a more efficient newer model gas furnace. If you are changing to electric to reduce your carbon footprint, the calculation would likely be a little different.

Monica’s choice

Monica was patient. She didn’t really want to replace perfectly functional appliances before their time.

However, a big motivator for Monica was a leaking air conditioner. Leaking refrigerant is a serious issue. Since heat pumps also use refrigerant, knowing how to see the signs of a refrigerant leak and getting it fixed quickly remains an essential home maintenance responsibility.

One way to cover this base is to pay for a relatively cheap yearly tune-up from a licensed HVAC company and specify you want them to be sure there are no leaks. Some signs of leaking refrigerant include higher than normal bills, longer than normal time to cool or heat, and not actually blowing cool or hot air.

Monica decided her older, leaking unit needed to go. She could have gotten it repaired or simply replaced it with a more energy efficient model air conditioner but she decided to take a bigger step, toward home electrification. Monica was motivated to reduce her carbon footprint, but this move made financial sense as well.

So in 2020, Monica installed an electric heat pump mini-split system in her home. This gave her a new energy efficient air conditioning system and an electric source of heat.

Sticking with her slow and steady approach, Monica left her gas furnace and the central ducting system in. She uses it on occasion, especially when she needs to heat the back bedrooms for guests. Because the mini-split heats a room more slowly than her old forced air system, which uses ducts, she decided to leave it in because it provides a powerful way to circulate the air for general ventilation and for hurry up situations.

The only negative she can think of is the appearance of the air-handler units up near the ceiling. But she got used to that and doesn’t notice them now.

What’s a heat pump?

Heat pumps are an efficient method of heating because they remove heat from the surrounding air. Even when it’s cold, there is heat in the air that can be “mined” by a heat pump. Running as an air conditioner, heat pumps are no different from a “regular” air conditioner. The new part about mini-split technology is using the same method, in reverse, to heat air.

Mini-split systems have an outdoor compressor unit and indoor air-handling units. The air-handling units are mounted near the ceiling, one per room. This type of system provides maximum flexibility and Monica took advantage of that. She installed an air-handler unit in the living room, family room, and master bedroom. She chose not to bear the expense of installing units in the two small bedrooms since they are little used at this point. Units can always be added later if the need arises. The units can also be turned on and off individually. So, she can heat or cool only the room she is in, saving even more energy.

See the Cool Davis resources below for lots of great links to learn more about how heat pumps work, and what you need to know to include them in your planning.

Next up: That gas burning water heater

Next in the succession of failing appliances was her old gas water heater. In November 2022, it finally failed. Monica took the next step towards all-electric and replaced it with a heat pump water heater in a short amount of time. In this respect, Monica got lucky. Replacing a gas water heater with an electric one can be a lengthy process.

Once a gas water heater has failed, many people opt for the quickest option, a new gas water heater. Changing to electric requires running a 220 electrical line, and, of course, securing a new water heater and having it installed.

Monica was able to slide into a cancellation, the contractor had the heat pump unit she wanted in stock and the switch occurred in one day. That is not always the case.

The EPA recommends looking to replace an old water heater after 10 years of service.  That is an efficient and cost-effective time to do so and allows for a move to a cleaner energy future.

Benefit budgets and the environment

Monica is happy with her new water heater. It provides plenty of hot water to meet her needs. She thinks the higher up-front cost was well worth it and expects it will be returned in energy savings over the years.  As an added bonus, since it is installed in the garage, the cold air it emits after removing some heat helps to cool the garage in the summer.

All in all, Monica is moving consistently towards a cleaner running, more energy efficient home. She is doing it in a way that benefits both her budget and the environment. It is a path that many can and should take.

More reading

Other homeowner stories

Cool Davis home electrification resources

All-Electric Heat Pumps FAQs (highly recommended!)

Video of Clean Energy Home workshop (Cool Davis Home Energy & Efficiency YouTube playlist)

Presentation: Make A Plan-Clean Energy Home Workshop Presentation Final_PDF

The Electrification Path to Our Fossil Free Future by Chris Granger

Cool Davis Home Energy webpage

Turn Off the Carbon Pump and Turn on the Heat Pump! Heat Pumps Explained in Basic Terms by Kristin Heinemeier

Cool Davis Understanding My Home Worksheet Final

Cool Davis All-Electric Planning Guide Final

Cool Davis HVAC Common Terms

Cool Davis Working w Contractors Cheat Sheet Final

Cool Davis Contractor Bid Comparison Table


Visit our Ways to Save webpage for utility bill assistance programs and incentives.

Read about new federal home energyincentives: Inflation Reduction Act of 2022: Actually a Climate Busting Bill by Michael Kluk

Summary of new federal home energy incentives available late in 2023:

  • Increases the credit for energy efficient home improvements such as added insulation, from 10% to 30%, and extends them through 2032.
  • Expands the credit to cover the cost of home energy audits up to $150 and electrical panel upgrades up to $600.
  • For residents that fall below 150 percent of an area’s median income, establishes a rebate program of up to $14,000 per household including $8,000 for heat pumps, $1,750 for heat pump water heaters, and $840 for electric stoves. Also includes rebates for improvements to electrical panels or wiring and home insulation or sealant.