Hot Water recirculation issue with Hep2o

[PaulD]

So has anyone read the 82 page Hep2o installer guide ? - https://wavin-digital-indianajones-prod.storage.googleapis.com/assets/category/e2adbf25-727a-4c44-82a8-9aec62d2978e/2f06b06d-06d0-4c8f-9905-99bb59b2ebf4/70ab700c-d7e5-4b82-96dd-4b5cc76cc487

 

I'm currently designing my new build water system and was a little surprised to read this, anyone have an opinion on this - I'm sure people use Hep2o for this all the time ?  - 

 

Continuously operated re-circulating systems (Secondary Hot Water Circulation / Ring main installations)

 

A continuously operated re-circulating system is a waterreplenished circulating system which is maintained at a constant high temperature to provide a constant source of hot water. Continuously operated re-circulating systems are used to distribute constant hot water to draw off points that may be distant from the heat source or hot water storage vessel. Continuously operated re-circulating systems are very different from conventional hot water supply and central heating systems found in domestic properties, for which our products have been tested to, under either BS 7291 2010 Class S or WRAS approval standards, and for this reason Hep2 O products must NOT be used on any continuously operated re-circulating systems as they are not approved under the current version of these standards.

[Dan F]

Continuously operated re-circulating systems are a bad idea anyway.  Put the recirculation pump on a timer, or get an intelligent one (Grundfos Comfort Autoadapt) and it won't be on continuously anyway.

 

Also, before you put recirculation in, consider the radial approach with right-sized pipe per fitting to avoid recirculation if possible.

[PaulD]

9 minutes ago, Dan F said:

Continuously operated re-circulating systems are a bad idea anyway.  Put the recirculation pump on a timer, or get an intelligent one (Grundfos Comfort Autoadapt) and it won't be on continuously anyway.

 

Also, before you put recirculation in, consider the radial approach with right-sized pipe per fitting to avoid recirculation if possible.

Yes Dan, would definitely be on a timer anyway, sorry for my naivety - tell me more about the radial system ? 

[JohnMo]

25 minutes ago, PaulD said:

Continuously operated re-circulating systems (Secondary Hot Water Circulation / Ring main installations)

You are reading hotel, hospital, care home, etc, not a house. As said bad idea if hot water circulation that way, you would need deep pockets and suitable mixers prior to every tap.

 

Get a secondary circulation pump with in built time and thermostat. If you are having a mixer valve on the hot water outlet, you need to arrange so as to allow cold water to enter the system also.

[Dan F]

59 minutes ago, PaulD said:

Yes Dan, would definitely be on a timer anyway, sorry for my naivety - tell me more about the radial system ? 

There is a lot on the forum about this approach, but at a high level instead of running 28/22mm around the house which i) loses a lot of heat and ii) requires recirculation if you don't want to wait 5 minutes for hot water, you have a very short run from UVC to a manifold and then from a manifold you pipe to each fitting.  Basins can use 10mm, which means a minimal volume of water and often no need for recirculation. The same for showers which can often use 15mm.   Exact sizing depends on design flow rates, pipe lengths etc. but that's the principal.

[cherryfountain]

I have used Pegler Tectite MLCP  pipe for all my H+C pipe work . I found it an excellent product bends like copper comes in 50mtr coils,no joins under the screed . You need to use there pushfit fittings and inserts also a couple of special tools to prepare the pipe.