Friday, 29 September 2017

Just how smart are smart homes?

When I first lived in Tokyo in the mid 1980's I remember being out somewhere and a friend got up to use the telephone. It was a payphone since this was before the age of mobiles. He didn't say anything, but punched in some numbers then put the phone down. He told us he'd just started the bath running at home.

If you don't know what a payphone is,
you probably won't know what this is either
This seemed like science fiction to me with my perspective from the primitive plumbing of England. Indeed it was science fiction compared to the Tokyo flat I was staying in where there was no running hot water, and the bath had to be filled with cold water, then heated by circulating water through a gas burner. Once, after a long day, I got into one such bath while the heater was still on. I dozed off in the bath and woke up very hot, and when I moved I got even hotter since I had been cooling the water immediately around me.

Most bath heaters had simple mechanical timers in the switches, so they would not overheat the bath. Even in the 1980s some of them could be programmed to switch on at a certain time, so the tub would be hot when you got home.

We can't call our bath on the phone, or send it text messages, but it can be programmed to come on at a certain time, and it does know how to say "I'm filling up the bath" and will happily tell us "The bath's ready". Unfortunately it doesn't know how to say "Whoops, I ran out of water so your bath is luke warm." And the phrase, "Hey, you forgot to put the plug in, you idiot" is also missing from its vocabulary. In both cases, the light just goes off and it remains silent. It's really not very smart.

So how smart are smart houses? Not very, is the short answer. Will they help us to save energy? Our bath could have saved us a few hundred litres of hot water if it just knew to tell us that it wasn't filling up and we'd left the plug out. So excuse me if I'm skeptical of the age of the smart house and the brighter future offered us by the internet of things.

If you want energy efficiency, then it is dumb things that will deliver: geometry, wall thickness, window quality, airtightness and attention to detail in the construction.

You can get gadgets if you want, and they may make your life better, but if you want to save energy start with the thermal envelope. You can stick as much as you like onto the envelope later. This applies to solar panels too, which are probably a good idea to add to your house, but they will not make your house more energy efficient. Putting insulation under the roof is a much higher priority than putting solar panels on top of it.

But don't just take my word for it. In Bringing users into building energy performance: Learning to live in a smart home, Tom Hargreaves, Charlie Wilson & Richard Hauxwell-Baldwin tell us that smart home devices are "technically and socially disruptive", are limited by the householder who is using them, and have a steep learning curve with few people to help you climb it. They also find "little evidence that smart home technologies will generate substantial energy savings and, indeed, there is a risk that they may generate forms of energy intensification."