would you recommend a hot water loop?

[trevw]

Hi,

I've just had a single storey extension put in which has made the house quite long, the hot water run to the kitchen tap is going to be in excess of 20metres.. would you recommend a hot water loop? Any Pros and cons? The old run was around 10ish m and that seemed slow.

Also, I did hear that you can have a gravity hot water loop if you know what you are doing but from the posts I could find on here there sounded like there was an issue..

System details: Vented copper cylinder on first floor, cold water storage in loft, condensing boiler.

any help welcomed..

cheers

Trev

 

[mrgas]

Hot water circulation can be very beneficial if you are concerned about water use. You waste a lot of water waiting for the dead leg to run down plughole. You also waste energy loosing the hot water left sitting in the dead leg.
In circulation systems it casn be argued that you waste electriciy on circulating water and waste energy in the inevitable heat losses in the long runs of hot water.
Gravity systems are inpractical as (simply)you need a continous fall.
You therefore need a pump. As you are pumping 'fresh' domestic water a bronze pump is needed to stop rusting. These are fairly expensive (£200ish inc tax).
You also should have a timer system fitted so water is circulated at times needed and not in the middle of night.
Pipes should be lagged as you will increase the heat losses through having a long run of hot pipes.
I think they are well worth having. Having near instant hot water at point of use is a blessing.
Hope this ramble helps

 

[trevw]

thanks mrgas, very helpful. Have been looking around a bit for pumps and found a bronze Wilo at £138 inc - have tended to use Grundfos in the past, are wilo any good?

http://www.pumpsukltd.com/StockItem...roductID=1669&oRef=-1&section=2&Item=unassign

This seems to use 20w on its lowest setting from the data sheet which seems reasonably low..

I would be planning to only use this for the hot water taps (ktichen/bath/ensuite) and not the showers as they will be pumped and from a seperate take off from the tank..

Any issues to watch? Did I read something somewhere about a checkvalve being required? (Have done basic hot water system plumbing with familly help but not even seen a hot water circulation system) The data sheet on the pump seems to say it can go on either flow or return.. any preferences?

forgot to metion, water softener already installed

thanks again

Trev

 

[mightyworthit]

Just caught this thread , sorry reply a bit late.
I should thoroughly recomend that when piping up the circuit you place air release valves in any places where air may get trapped, ie where pipe work rises then falls. The water carried is fresh oxygenated and over time oxygen will be released and will find the highest points. Be aware that hot mustn't be above 60 degrees C, especially in hard water areas.