Most Energy Efficient Pump

[Rehan Saeed]

I'm looking into pumps for an underfloor heating system. I'd like to get one that is as energy efficient as possible but also quiet. I read the guide below:

 

https://www.anchorpumps.com/blog/best-central-heating-pumps-expert-guide/

 

It seems the Grundfos ALPHA3 15-50/60 is the most energy efficient with an EEI of 0.17 but it's pretty expensive. In second place is the Stuart Turner ST 15/60 with an EEI of 0.18. This one is one third the price of the Grundfos! If looks are anything to go by, it also looks a lot cheaper too.

 

Since the EEI only differs by 0.01, how much of a real world difference does that actually make over the course of a year? Can anyone give me a good recommendation for an energy efficient pump?

[Nickfromwales]

https://www.tradepumps.com/grundfos-alpha3?tagrid=55270474

 

Change of £197 here

[PeterW]

Wilo for me - they are near silent. 

[Nickfromwales]

42 minutes ago, PeterW said:

Wilo for me - they are near silent. 

Yup. I've started to specify these, but the plugs are shit.

[Rehan Saeed]

59 minutes ago, PeterW said:

Wilo for me - they are near silent. 

The best efficiency I found for these was 0.20. So not as good but good to know they are good for low noise.

[dpmiller]

how many watts of a difference do you think there'll be between two already-efficient pumps?

[Rehan Saeed]

I found that a pump typically uses about 50W of energy, so I did a bit of rough math and found it costs about £4 per month to run (assuming its run for 8 hours a day, thats or £48 per year or £480 over a ten year lifetime). What I'm unsure of is how an energy efficiency index of 0.17 for a Grudfos or 0.2 for a Wilo affects those numbers.

 

[Rehan Saeed]

I found the details. A Wilo Pico power usage:

 

 

The Grundfos in comparison:

 

 

The Wilo cost assuming its always at max speed (not true but to get an idea) is £38.16:

 

 

The Grundfos cost per year is £28.68:

 

 

The Grundfos will save you £9.48 over a year or £94.80 over ten years by my calculations. Not a huge difference but worth spending £20-£50 extra on a better pump IMO.

[PeterW]

1 hour ago, Rehan Saeed said:

I found that a pump typically uses about 50W of energy

No idea where you’ve got that from - the Wilo Yonos is 17-20W max. That’s £10 per year based on 36p/kWh and 8 hrs day/180 days per year.

 

Your average TV on standby uses about 4 times that…