EU Eco Design Directive - Energy saving pumps

Tch.

The thing is about running the CH system a constant pressure so allowing the thermostatic valves work better. The motor is variable speed, there are small savings there too.

They have been used for donkeys years commercially. There is a pressure sensor on the pump controls motor speed.

More on the topic here.

Can someone explain to me what it is that is "energy efficient" here?

Is it that the pump itself uses less energy to do the same thing or is it that it (somehow) pumps the hot water around in a more energy efficient way?

tim

There are many things you can do to save some money, unfortunately for the poorer people in society, these things generally cost up-front to save in the future and they just don't have the spare cash to hand. They dread anything failing and simply have to do without or repair/replace with the option with the lowest immediate cost.

SteveW

The pump itself uses less energy - this is achieved through the design (e.g. permanent magnet motors) and variable speed control - a pump doesn't always have to provide the full flow rate of a system e.g. when TRVs shut, with a variable speed pump, the pump slows down as the demand decreases.

That would be the idea behind the green deal.

You have stuff done and the cost is added to the electricity bill.

Both.

Doesn't answer either of my questions. You bought it hook line and sinker, again.

MBQ

If the thermostatic radiator valves work correctly (ie by reason of constant pressure on the system), less heat will be required to heat a room and hence less boiler fuel needed.

It takes a quarter of the power to run a pump if the speed is halved. So, there are significant savings in the electricity used.

If the pump is not "throttled" there will be less cavitation and hence less wear in the pump, (Also maintaining efficiency.)