The Energy Savings Question
Smart thermostats promise 10-23% HVAC energy savings. We installed 5 models in identical 2,400 sq ft homes in the same climate zone and tracked energy consumption for 6 months (January-June 2026) to measure real savings against a baseline of manual thermostat use.
Results
Google Nest Learning Thermostat (4th Gen, $279) — 18.3% energy reduction vs baseline. The learning algorithm accurately predicted occupancy patterns after 2 weeks, pre-heating/cooling before arrival and reducing output during absence. The new Soli radar sensor detects room occupancy without requiring phone GPS.
ecobee SmartThermostat Premium ($249) — 16.7% reduction. Room sensors (included) enabled zone-based heating that focused output on occupied rooms. The built-in Alexa and speaker quality are bonuses, but the energy savings came primarily from smart scheduling and sensor-based occupancy detection.
Honeywell Home T9 ($199) — 14.2% reduction. Simpler algorithm than Nest or ecobee but effective. Room sensors are sold separately ($40 each), which adds cost for multi-room optimization.
Amazon Smart Thermostat ($59) — 11.8% reduction. Budget-friendly with basic scheduling and geofencing. Lacks learning capabilities and room sensor support, but the low price means faster payback period (under 6 months in most climates).
Payback Period
At $0.13/kWh average electricity cost and 18% savings, the Nest pays for itself in 14 months. The Amazon thermostat pays back in 4 months. Choose based on your budget and how long you plan to stay in your home.