Vented or Unvented Cylinder

[blueplanet]

Hello

Would you recommend a vented or unvented cylinder? I have an indirect vented system at the moment. The flow rate from the upstairs taps is low.

We are having solar thermal installed and thus the cylinder will be changed. We can have a new vented or unvented cylinder installed.

What would you recommend? Will the flow rate improve from an unvented? The house was built in 1985 if that is relevant in terms pipework.

Thanks for your input.

 

[Chuck]

Would you recommend a vented or unvented cylinder?

Depends on the capacity of the incoming mains water supply not all can support unvented systems. That said, unvented is preferable in my opinion becauseI don't like having cold water tanks in roof spaces.

 

[steadyon]

1. Tend to agree with Chuck. However, do remember that if the water is off for any reason, you will have neither hot nor cold until it is restored. With an unvented system you have at least tank fed hot and cold until the cold water storage cistern is exhausted.
2. You need a minimum of 2.0 bar dynamic water pressure (dynamic = pressure measured with a mains fed tap running) and a flow rate of 20 litres per minute (preferably more) to run an unvented cylinder.
3. An unvented cylinder needs a pipe to drain off any water from its pressure relief devices. These are best terminated outside, although inside will do provided the drain pipework can take the potential temperature.