Hot and cold copper pipes

[amavadia]

Hi all

 

I am fitting a new hot water pipe to a sink downstairs. The boiler is above the kitchen. Along the back wall of the house, which is where the pipe will go, there is a horizontal 22mm cold water pipe. The new 15mm pipe needs to go down and cross over this pipe in-between the floors of the house.

 

I understand the idea is to keep the hot and cold water pipes a reasonable distance apart and was just wondering what the best way to do the crossover is? I have seen crossover pieces you can buy but putting it over the 22mm pipe, there is very little space and it seems a bit too tight to be good.

 

Are there any other options?

 

Thanks

[Russell griffiths]

Insulation on the cold pipe before you cross over it. 

[Miek]

What's the issue? If its heat loss this would be negligible, the pipes can cross. Bend the pipe to suit the space, or buy a crosover fitting. 

[amavadia]

The problem isn't heat loss on the hot, its keeping the cold cold. Under 20 degrees to prevent leigionaires.

 

Would a few wraps of hair felt be enough to insulate the cold? There isn't enough clearance to use any kind of foam lagging.

[Jeremy Harris]

29 minutes ago, amavadia said:

The problem isn't heat loss on the hot, its keeping the cold cold. Under 20 degrees to prevent leigionaires.

 

Would a few wraps of hair felt be enough to insulate the cold? There isn't enough clearance to use any kind of foam lagging.

 

There's no Legionaires risk with a cold mains water pipe at all, unless you're on a private water supply or the cold water is coming from an open tank (in which case it shouldn't be used as drinking water), and even then the risk is very tiny.  Mains water contains enough residual disinfection to ensure it remains bacteria-free throughout the distribution network, as long as that network remains sealed (i.e. no open storage tanks).

 

Even then, it takes several days for Legionella to multiply at lower temperatures (say, around 20°C to 25°C) and a cold pipe will almost always have regular flow through it.  The risk is no worse than a normal household going on holiday for a couple of weeks in summer, when all the pipework will get warm for days on end.