Smart Thermostats near you

EPA's key product criteria for smart thermostats, under a specification effective January 1, 2017, set out a functional list and a small set of measured device limits. Reading them is a good corrective to marketing copy, because several of the requirements are about behaving sensibly rather than about being clever.

The savings side of the certification is where the detail repays attention. EPA does not measure dollars or fuel; it measures reduction in equipment run time, annually, as a percentage. To demonstrate compliance, smart thermostat service providers use EPA-provided software to analyze and combine a year of data from hundreds of their customers' homes, reflecting how the thermostats were actually used, and to calculate national savings metrics for heating and for cooling.

The thresholds are expressed twice, in two different statistics, and the reason is worth understanding. For heating, the lower 95 percent confidence limit of the weighted national average annual run time reduction must be at least 8 percent, and the weighted national average of 20th percentiles must be at least 4 percent. For cooling, the same two measures must be at least 10 percent and at least 5 percent. EPA explains that the lower 95 percent confidence limit is similar to an average but takes into account the chance that the particular homes sampled were all higher savers, and that the 20th percentile means four out of five homes in the sample saved at least that much.

The practical reading is that the second number is the honest one for a cautious buyer. A certified product has shown that the bottom of its distribution is not zero, which is a real and unusual claim for a consumer product, but it is a claim about a national sample of households, not about yours. A house that is already run on a disciplined schedule has less run time to remove than one held at a constant setpoint, and the same device will show up very differently in the two.

There is a third measure in EPA's savings criteria that exists purely because of heat pumps, and it is a reporting requirement rather than a threshold: average resistance heat utilization for heat pump installations, reported as a national mean in 5 degree Fahrenheit outdoor temperature bins from 0 to 60 degrees Fahrenheit. EPA collects it because a control that hits its run time reduction targets by leaning on electric resistance backup heat has not saved anybody anything.

That is the failure mode to watch for in an American house with a heat pump. Aggressive recovery from a deep setback, a changeover setting configured as though the equipment were a furnace, or an outdoor temperature lockout left at a default can all call the strip heat in more often than the old control did. The bill goes up, the thermostat reports that it hit its targets, and nothing on the wall says which kind of heat has been running.

Two things help. First, insist that whoever installs it configures the equipment type, stage count, backup heat type and changeover behavior deliberately, and then shows you how the thermostat reports auxiliary or emergency heat. Second, use shallower setbacks on a heat pump than you would on a furnace, and check the run time reports in the first cold week rather than at the end of the season.

The utility connection is built into the certification. EPA requires a certified smart thermostat to be able to work with utility programs to prevent brownouts and blackouts while preserving the consumer's ability to override those grid requests, and describes certified models as designed to be compatible with the programs some local utilities offer to homeowners in their service territory.

Read the enrollment terms rather than the headline incentive. The things that differ between programs are how many events a season, how long each one lasts, how far the setpoint moves, whether the adjustment is pre-cooling or a straight setback, how an opt-out is exercised and whether opting out too often removes the incentive. The override right is in the ENERGY STAR criteria; the commercial terms attached to using it are not, and they are the utility's.

On the federal side, be careful with older advice. The IRS states that the Energy Efficient Home Improvement Credit, the section 25C credit, can be claimed for improvements made through December 31, 2025. Whatever a page written earlier in the decade says, check the IRS page for the current position before you count on a federal credit, and treat utility and state programs as the live route.

Compatibility is settled before purchase, not at the wall. ENERGY STAR's own buying advice is to make sure the smart thermostat you purchase is compatible with your heating and cooling system, and that for the very highest efficiency heating and cooling equipment you may want a controller from the same company, giving equipment rated at 20 SEER or higher as an example. That is a real constraint on high-end variable-capacity systems, where a third-party control can leave the equipment running in a cruder mode than it is capable of.

The second constraint is connectivity, and the criteria acknowledge it from both ends. The certification requires the device to keep working as a basic thermostat without a connection to the service provider, and ENERGY STAR's practical advice is to make sure a Wi-Fi thermostat is reasonably close to the router, and to consider a range extender if it is too far. A thermostat that drops off the network every few days will not deliver schedule, geofencing or utility program behavior, whatever it does when it is online.

The third is the household. A smart thermostat earns its savings from occupancy patterns, so the install is only finished when someone has set up the accounts, the geofencing and the schedule for the people who actually live there, and has cleared the permanent hold that so often gets left in place during commissioning. Ask for that handover as part of the job rather than assuming it happens.

The device price is the small part. What moves a quote is whether the existing wiring can power the thermostat or a new conductor has to be pulled from the air handler, whether the equipment is single-stage or multi-stage, whether it is a heat pump with backup heat that needs deliberate configuration, whether the system is zoned or communicating and therefore wants a manufacturer's own control, how many thermostats there are, and whether anything has to be relocated because the current position reads the hallway rather than the rooms. On a simple single-stage system with the right wiring this is short work; on a zoned heat pump it is not.

LokalMatch is a place to collect quotes and compare them, not a contractor. You describe the equipment and the control once, HVAC pros serving your area receive the request, and the ones interested contact you. Pros pay for the requests they receive and homeowners pay nothing. LokalMatch does not do the installation, does not set prices and does not vet, rank or recommend anyone who contacts you, so ask each pro which model they propose, whether it is ENERGY STAR certified, and how they will configure and demonstrate the backup heat settings.