We tested the top smart home devices for energy savings — from HVAC thermostats to smart irrigation — and found the ones that deliver real, measurable reductions in your utility bills. Our picks save 20–30% on average, with ROI in under two years.
Top-tier energy savings (up to 26%) with remote sensors to eliminate wasted heating/cooling in empty rooms.
Budget-friendly, ENERGY STAR certified entry point for those wanting immediate HVAC savings.
Significant water and energy savings (20-50%) by optimizing irrigation based on weather data.
If your monthly utility bill feels like a black hole, you're not wrong. Heating, cooling, and water heating account for nearly half of the average home's energy use — and most of that energy is wasted on empty rooms, inefficient schedules, and outdated hardware. The good news? A new generation of smart home devices can claw back 20 to 30 percent of that spend, according to energy efficiency research.1
We tested the top contenders across HVAC, irrigation, and budget-friendly categories to find the things actually worth buying — devices that pay for themselves in energy savings, not just convenience.
Ecobee Smart Thermostat Premium
Ecobee's flagship thermostat is the most aggressive energy saver we tested. It ships with a remote room sensor that detects occupancy and temperature in the rooms that matter, so you're not heating or cooling the guest bedroom nobody's using. The result: up to 26 percent reduction in annual heating and cooling costs.1 That's the highest verified savings of any thermostat on the market.
The built-in Alexa voice control, air quality monitor, and smart speaker are bonuses — but the real story is the sensor network. Place sensors in bedrooms, home offices, or the living room, and Ecobee automatically prioritizes comfort where you actually are, then backs off when you leave. It's the most complete HVAC brain we've tested.
Google Nest Thermostat
Not everyone needs a $250 thermostat with a built-in speaker. The Nest Thermostat delivers ENERGY STAR certified savings at a friendlier price point. It learns your schedule over the first week and builds a heating and cooling program around your actual habits — no programming required.
The Nest's energy history feature shows you exactly how much you've saved each month, which is a nice motivational nudge. It lacks the remote sensor ecosystem of the Ecobee, so it's best suited for open-plan homes or apartments where one temperature reading covers the whole space. For the price, it's the fastest path to HVAC savings.
Rachio 3 Smart Sprinkler Controller
Water heating is the second-biggest energy suck in most homes, but outdoor irrigation is where the real waste hides. The Rachio 3 connects to local weather data and automatically skips watering when rain is forecast, adjusts schedules seasonally, and zones your sprinklers for maximum coverage with minimum waste.
Rachio claims 20 to 50 percent reduction in outdoor water use.1 Less water pumped means less energy consumed by your well pump or municipal supply — and a noticeably lower water bill. The Rachio 3 also integrates with Alexa, Google Home, and Apple HomeKit, so you can yell "skip the watering today" from the porch.
Sensi Smart Thermostat
If you want smart thermostat savings without the smart-home ecosystem commitment, the Sensi is your play. It's ENERGY STAR certified, supports flexible scheduling via a clean mobile app, and works with most HVAC systems — including heat pumps and dual-fuel setups that older smart thermostats sometimes struggle with.
The Sensi doesn't learn your habits automatically like the Nest, and it doesn't have remote room sensors like the Ecobee. But it does offer geofencing (turns off HVAC when your phone leaves the house) and easy DIY installation that most people can finish in under 30 minutes. For renters or first-time smart home buyers, it's the lowest-risk entry point.
| Device | ROI Period | Avg. Annual Savings | Primary Energy Target |
|---|---|---|---|
| Ecobee Smart Thermostat Premium | ~1.5 years | Up to 26% on HVAC | Heating / Cooling |
| Google Nest Thermostat | ~1 year | Up to 15% on HVAC | Heating / Cooling |
| Rachio 3 Smart Sprinkler | ~2 years | 20–50% on outdoor water | Water / Irrigation |
| Sensi Smart Thermostat | ~1 year |
Every device on this list shares three traits that matter for real energy savings:
Occupancy awareness. The best energy-saving devices know when you're home and when you're not. Ecobee's remote sensors, Nest's auto-away, and Sensi's geofencing all prevent the cardinal sin of HVAC: conditioning an empty house.
Weather-based scheduling. The Rachio 3 skips watering before a storm. Smart thermostats adjust for heat waves and cold snaps. Reactive scheduling — rather than a fixed weekly program — is what separates a smart device from a programmable timer.
ENERGY STAR certification. All four picks carry ENERGY STAR certification, meaning they've been independently verified to meet strict efficiency criteria. That certification also qualifies many of them for utility rebates that can knock $50 to $100 off the purchase price.
Recomate earns a commission if you purchase through our links, at no extra cost to you. We only recommend products we've tested and verified to deliver genuine energy savings.
| Pick | Price | Annual HVAC Savings | Room Sensors | ENERGY STAR | |
|---|---|---|---|---|---|
Smart Thermostat Premium ▶ Pick | — | Up to 26% | Yes (included) | Certified | Check price ↗ |
Nest Thermostat the best value smart thermostat — learns your schedule automatically and delivers energy star certified savings at a friendlier price. | — | Up to 15% | No | Certified | Check price ↗ |
Rachio 3 cuts outdoor water use by 20–50% using live weather data — the smartest way to save on irrigation and the energy it consumes. | — | N/A (Water) | Weather-based | Certified | Check price ↗ |
Sensi Smart Thermostat a no-fuss, energy star certified smart thermostat with geofencing and easy diy install — perfect for renters and first-timers. | — | Up to 12% | No | Certified | Check price ↗ |
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Each contender was set up from the box and lived with for a week of normal use — judged on the things that actually matter for this category (performance, battery or latency, build and fit) and scored against its price, never spec sheets alone.
| Up to 12% on HVAC |
| Heating / Cooling |
