Just in time for Earth Day (and before another summer of expensive AC bills), Amazon is offering up the Nest programmable thermostat for a (rare!) discount.
Nest Thermostat on Amazon,
$249 now $219
While there's quite a few other learning thermostats on the market that are aiming to close the gap, Nest was the first, and is still considered the best amongst its competition (see: Wirecutter and CNET). And now it's on Amazon for a $30 discount.
If you already have a digital thermostat, it's not that difficult to install Nest yourself, though if you'd rather not be bothered, Amazon also offers pro installation for certain zip codes for about $130. It's worth it even if you're in a rental—hold on to the old device, and swap them back so you can take the Nest with you when you move.
While the Nest learns your heating habits and adjusts accordingly, that's not the only thing it does. Nest can be used as a hub for a smart-partment; the company also makes a smoke and carbon monoxide detector that can be controlled by smartphone as well as security cameras, but the Nest itself works with other products, too, like smart lightbulbs and doorbells. It will also connect to Google Home and Amazon's Alexa (so you can holler at a robot to change the temp for you instead of doing it yourself). It'll even help with laundry—if you have Whirlpool's smart appliances, it'll switch the machines to eco mode while you're gone, and occasionally tumble clothes in the dryer to prevent wrinkling.
And really, having a device that learns your habits and preferences and reduces your energy bill is not only good for your wallet, but good for the planet. Plus, it's also good design (which you probably care about at least a little bit, seeing that you're reading this on Apartment Therapy!).