Wednesday, 12 June 2013

When to switch it off

The best way of reducing the energy consumption of a device is to switch it off.

Pretty obvious, but the marketing people won't tell you this. Car adverts will show vehicles cruising wilderness or open road, boasting the high efficiency. They won't show them parked in the garage when their miles per gallon are up at infinity.

In fact, not buying the device in the first place is better still, but it's usually too late for that.

We switched off our electric radiator at the end of February, and until then it was running on a timer so it would only come on around six in the morning.

We also switched off the underfloor heating at the end of February, and as far as heating goes winter was over. Of course the story outside was somewhat different, and there was still snow and plenty of cold nights, but not in the same league as January and February.

Also, even though we stopped using our hot water for heating the house, it didn't make a major dint in our electricity consumption for another week. This is presumably the wisdom of the Eco Cute, which decides how much heat to generate depending on the maximum usage over the past week. Also, the fact that the energy it uses depends more on how cold it is outside and how hot you want the water to be in the tank, rather than how much heat you use. As the night goes on and the tank gets hotter and the air outside gets colder, the heat pump gets less and less efficient as it has a higher gap to lift the heat over.

Anyway, it's likely that at least some of the heat ended up in the house, since that's where the hot water tank is, and it was not all being poured down the drain as hot water, which is one of the less-advertised habits of these eco-wonder. Even if the heat went into the house, it willl have been heating the air rather the foundation, much less efficiently.  So the heating didn't fully switch off until the second week of March.