In January last year, Google agreed to buy Nest Labs, a start-up company making thermostats (and, more recently, smoke detectors) for $3.2 billion. It’s an astonishing amount of money, particularly for a business that was only started in 2010. The success of the Nest ‘smart’ thermostat was based on it replacing traditional central heating programmers, which consumers find difficult to set up and, more important perhaps, it’s ability to learn. The Nest thermostat is a beautifully designed circular control that learns the pattern of temperatures that you set over time. Within a few days, it programs itself to repeat the pattern.
The Nest controller turns heating off when nobody is at home, can be set up to ensure that pipes don’t freeze during periods of very low temperatures and can be remotely controlled over the Internet using a phone, tablet or laptop computer. The idea is that consumers not only gain better control over their home environments but they reduce their electricity bills by optimizing energy usage.
Many of us are familiar with rectangular thermostats so it may come as a surprise that Honeywell first introduced a round thermostat, called the T-86 Round, in 1953. Derivatives of the 62 year-old original are now used in more homes than any other. And the T-86 is still in production today. The Nest is different because of its electronics, it’s ability to learn, and the way it uses the Internet for control and monitoring. Not surprisingly, Honeywell didn’t take long to create a competitor. Its own smart product, called the Honeywell Lyric, announced in June 2014, takes a different approach. Rather than learning your habits, it uses something called geo-fencing. Your cellphone tells it if you’re at home, so it optimises for comfort. If you are away from home, it optimises for energy savings. It has a lot of other tricks up its sleeve too – far too many to go into here.
So there’s a snapshot on the latest ‘intelligent’ consumer thermostats, but what’s happening in the industrial world? Well, our latest digital thermostat, the ET2011, doesn’t connect to the Internet, track you via your mobile phone, or learn your habits. But it features lots of things that its consumer counterparts don’t.
The ET2011 programmable thermostat: simple buttons and a big, bright, clear display
The ET2011 can be used with a variety of temperature sensors – thermocouples, PT100 or NTC types. It’s equally suitable for heating or cooling applications, and you can choose the way in which it delivers temperature control. Depending on your application, you can opt for simple on-off control, or P, PI, PD or PID (you can find out more about these control modes here). There are two relay outputs rated at 250V AC that can be configured for either control or alarm function, and a 12V/20mA solid-state relay control output. Of course, all this functionality and flexibility comes at a price. The tiny, rectangular (77 mm x 35 mm) ET2011 costs well under $100.