Unvented vs Vented Cylinder & Cold Storage Tank

Victorian House

Hi all,

I have come across some internet blogs (UK based) that have an advantage for unvented cylinder that no cold storage tank is required.

My understanding is that a cold water storage tank is always required to provide 24 hour back-up supply?

Is the main benefit of a unvented system that the hot water is delivered at a higher pressure?

Thanks

dathi

Victorian House wrote: »

Hi all,

I have come across some internet blogs (UK based) that have an advantage for unvented cylinder that no cold storage tank is required.

My understanding is that a cold water storage tank is always required to provide 24 hour back-up supply?

Is the main benefit of a unvented system that the hot water is delivered at a higher pressure?

Thanks

1. cold water storage is required under building regs taken from part G TGDs
1.3 The cold water supply to the kitchen sink should
be taken directly from the service pipe supplying
water to the dwelling; the cold water supply to the
bath or shower and the washbasin and to other
appliances in the dwelling should be from a cold
water storage cistern
2,yes it will be at higher pressure you can also use pump to increase pressure

Victorian House

dathi wrote: »

1. cold water storage is required under building regs taken from part G TGDs
1.3 The cold water supply to the kitchen sink should
be taken directly from the service pipe supplying
water to the dwelling; the cold water supply to the
bath or shower and the washbasin and to other
appliances in the dwelling should be from a cold
water storage cistern

Exactly - I just read a number of posts which were claiming that an unvented system means you don't require a cold water storage tank. Must have been copied across from a European website!

dathi wrote: »

2,yes it will be at higher pressure you can also use pump to increase pressure

One bugbear of mine is hearing a pump go off when you switch on the hot-water in a house (especially at 2am!). Would the unvented cylinder be a better recommendation if this is my preference or is there a world of difference between different pump systems.

John.G

Victorian House wrote: »

Exactly - I just read a number of posts which were claiming that an unvented system means you don't require a cold water storage tank. Must have been copied across from a European website!



One bugbear of mine is hearing a pump go off when you switch on the hot-water in a house (especially at 2am!). Would the unvented cylinder be a better recommendation if this is my preference or is there a world of difference between different pump systems.

Could you not fit a timer (or a switch) to stop it starting at night, you should still get enough flow through the pump to wash hands and refill the toilet cistern.

Victorian House

My understanding is that a pump isn't required to refill a toilet cistern which is straight from cold storage tank. Maybe a timer is a workable option though.

John.G

Victorian House wrote: »

My understanding is that a pump isn't required to refill a toilet cistern which is straight from cold storage tank. Maybe a timer is a workable option though.

You must (should) still wash your hands though so if you are happy enough to use cold water you could also feed this tap from the same supply. As you will probably have a power shower in the same bathroom which would be fed from the pump and I presume this would also feed the toilet cistern & the hot&cold basin taps then the timer/switch probably isn't a bad option.