navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address. Following continuous spam/hack attempts on the forum, "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Energy efficient pumps  (Read 2564 times)
Bodidly
Hero Member
*****
Offline Offline

Posts: 1555



« on: November 20, 2019, 08:55:50 PM »

I know it's not very glamorous but it's amazing how much energy can be saved with a modern circulation pump. Our UFH pump was starting to make some pretty odd noises and bearing in mind it's 10years old didn't begrudge buying a new one. I knew there more efficient options these days but was taken aback by the improvements. Our old Wilo used 99 watts at full speed. The new DAB one uses just 35 watts for the same job! Reading further I see that pumps use between 10%-20% of the world's electricity  Shocked
Logged
rogeriko
Hero Member
*****
Offline Offline

Posts: 1442



WWW
« Reply #1 on: November 20, 2019, 10:11:13 PM »

If you turned your old pump down to 35w it would have done the same job. Energy efficient pumps fail a lot more than old style pumps, just turn your old style pump down to the lowest setting and it will still work fine. To push water around the pipes needs only very little energy because there is no uphill or downhill, its a closed system.
Logged

Bodidly
Hero Member
*****
Offline Offline

Posts: 1555



« Reply #2 on: November 21, 2019, 08:46:37 AM »

If you turned your old pump down to 35w it would have done the same job.

Would it? We have UFH and if the flow rate is too slow you end up with cold spots at the ends of the runs.
Logged
marshman
Hero Member
*****
Offline Offline

Posts: 1003


WWW
« Reply #3 on: November 21, 2019, 10:07:24 AM »

If you turned your old pump down to 35w it would have done the same job.

Would it? We have UFH and if the flow rate is too slow you end up with cold spots at the ends of the runs.

A qualified YES from me.  It of course depends on your system but we have a 2 storey house with UFH on both floors, total of about 240 sq m.  There is just one pump, a Grundfos UPS 2, for the whole house.  After the GSHP was installed and this pump fitted I kept reducing the speed (and hence power consumption). I read the brochure and it has three "variable speed modes" where the speed varies according to demand (pressure). As I have the system running continuously 24/7 during the heating season I wanted the lowest power consumption possible. The pump is now running on its lowest variable speed setting where the power consumption is a mere 7 W.  This is what it says in the spec and I have measured it as well. So a 7 W pump running 24/7 for a large detached house -yes it can be done. Of course as I said it depends on your system. My UFH has 20mm pex pipes and is split into 8 loops on two manifolds,  (4 up and 4 down), 28mm pipe from buffer tank to manifolds. No idea of the total pipe run but I could work it out. The only floors that are "bare" are the kitchen & bathrooms, all the rest have thick carpets. This morning, 3 deg outside over night, the kitchen floor felt the same temperature all over (I wander around in bare feet in the morning as the floors don't feel cold!) and checking with an IR thermometer shows the temperature to be between 20.5 and 21.5 deg C all over the entire floor.

Just to add the original set up (water heated by a wood burning boiler stove) also had a single Grundfos pump installed in 1985. One of the "old" three speed pumps. That was quite happy on its lowest setting, but that was around 60W I think, and was still working perfectly after 30 years. In that scenario the heating was not on 24/7, but only for a few hours late afternoon/evening so heat output from the floor was a lot higher for shorter periods.

Roger
« Last Edit: November 21, 2019, 10:12:12 AM by marshman » Logged

3.15kWpk (15xSharp ND210)/SB3000. & 3.675kWpk (15 x Suntech 245WD)/SB4000TL, 10kW GSHP driving Wirsbo underfloor heating from 1200m ground loops. 10' x 7' solar wall (experimental). Clearview 650 Wood Burning Stove. MHRV - diy retrofit. Triple glazing.
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!