Long hot water supply pipe run

[superhands]

Hi,

Currently on a job where the hot water tank is in the basement with a 20 meter run to the loft then drops to the bathrooms and takes at least 3 mins for the hot water to come through so trying to look at a way of fixing this. I have thought about a secondary circulation but I'm not that keen on the idea.
I think maybe one of the problems along with the distance is that the pipe size is 1/14" for the first 10 meters then reduces down to 1" then finally reduces to 22mm to drop into the bathrooms.

Would it come through significantly quicker if the supply from the cylinder was run in 22mm all the way, and also would the pipe be large enough for 2 bathrooms(bath/shower cubicle in one just shower in the other), I'm kinda thinking it should be 28mm to supply both.

Would appreciate any thoughts on this

Thanks

 

[woodytheplumber]

personally I would try to find a way of moving the Hot water cylinder to a more central position in the house space permitting

 

[Jimbob]

Even in 22mm, anything over 10 metres 'should' have a secondary return.

Secondary return is your only real fix from the sounds of it, it's a great solution and work well with correct controls- timer and pipe stat, although it would help to downsize any oversized pipework.

 

[superhands]

There might be a way of moving the cylinder nearer, means a lot of pipework though. May have to consider the secondary return as an option, is there anything i need to consider with regard to air getting in etc?

Thanks

 

[lame plumber]

how do think air will get in?

 

[superhands]

I was thinking about pumping over and air getting in but thinking about it, it probably wouldn't happen. I'm not very familiar with this setup.

 

[Dotty]

The new smart pumps don't need timers or pipe stats, they formulate their own database over a few weeks based on usage, and keep updating that database including running a disinfection cycle during periods of non occupation.

Grundfos isn't the cheapest solution but this should give you a bit of an idea.

http://uk.grundfos.com/products/find-product/comfort.html#brochures

 

[diamondgas]

How much are they? Just paid a cupl of hundred, I think, for a 'brass' pump for me own house last year!!! Sound like a good idea though

 

[stevetheplumber]

it will probably work with out a pump with that height

 

[superhands]

thx will have a look at those