That he should have known better presupposes he's right. He may be in his circumstances, but having worked with two dozen Nests, my experience says this helps almost everyone.
I own nine Nests in two properties, a loft office with one zone and a two building home with eight zones. The loft is commercial central heat and air. The home is boiler heat with eight baseboard zones.
The Nest in loft saved me about 30% compared to prior years, and the Nests in home saved me closer to 50%.
The reason I saved so much in the home is thanks to the energy history view in the web or iPad app. I was able to see which zones were cycling on and off when, and adjust relative zone temps until all zones were sharing work equally. When all zones were naively the same temp, some zones were always on (lower floors) while others were never on (top floor). Balancing temps differently until I could see all zones cycling equivalently dropped my boiler burn time by 50%.
Based on this, I recommended these to a number of friends and family. Those with conventional central heat and air have all commented on savings they can see on their electric bill.
The one exception is a friend with commercial office properties. He switched to Nest and was having trouble, bill shot up! Turned out his tenants were mis-training the Nest, with the classic misunderstanding that turning it higher than our goal makes it adjust temps up faster. Nest was letting temps drop farther, then tenants would turn it to 85 thinking that would make it heat faster. It learned that, and was hitting 85 every morning then tenants trained to let it drop back to 75 during day. We tweaked the Away temps to stay closer to normal, switched off learning, and set a nice schedule. Now he's saving 30% or so as well.
I own nine Nests in two properties, a loft office with one zone and a two building home with eight zones. The loft is commercial central heat and air. The home is boiler heat with eight baseboard zones.
The Nest in loft saved me about 30% compared to prior years, and the Nests in home saved me closer to 50%.
The reason I saved so much in the home is thanks to the energy history view in the web or iPad app. I was able to see which zones were cycling on and off when, and adjust relative zone temps until all zones were sharing work equally. When all zones were naively the same temp, some zones were always on (lower floors) while others were never on (top floor). Balancing temps differently until I could see all zones cycling equivalently dropped my boiler burn time by 50%.
Based on this, I recommended these to a number of friends and family. Those with conventional central heat and air have all commented on savings they can see on their electric bill.
The one exception is a friend with commercial office properties. He switched to Nest and was having trouble, bill shot up! Turned out his tenants were mis-training the Nest, with the classic misunderstanding that turning it higher than our goal makes it adjust temps up faster. Nest was letting temps drop farther, then tenants would turn it to 85 thinking that would make it heat faster. It learned that, and was hitting 85 every morning then tenants trained to let it drop back to 75 during day. We tweaked the Away temps to stay closer to normal, switched off learning, and set a nice schedule. Now he's saving 30% or so as well.