Vaulted hallway

[eandg]

Our MVHR install finishes tomorrow but the design (by BPC) does not allow for an extract in our vaulted upstairs hallway, which is at the top of a large open stairwell (6m2 floorspace and 7m high. Slight but possibly uninformed concern is that we'll have a lot of stale hot air sitting under the ridge - should we order and fit another extract at the top of the stairs? 

[Thorfun]

We have no supply or extract in our entrance hall (also vaulted) which was designed by another company. So sounds like it’s normal to not have MVHR in a hallway. 

[Conor]

You wont need one.

[JohnMo]

Hallways are generally an area where air passes through so are ventilated by default. Example air is supplied to a living or bedroom, the air is extracted in a wet room, so it is likely to pass through the hall on its way to the wet room.

 

Also halls are not spaces where damp air is generated or people are present for long periods, so additional ventilation is not needed.

[Blooda]

We have none in our landing or hall, but do have an extract vent in a large cupboard on the landing, [as well as small radiator that never comes on] as SHMBO wanted an "airing cupboard" like we had in the last house, so a bit of air flow helps final drying and prevents moisture build up.

 

 

[Ola]

Our (BPC) design indicates a supply valve in ground floor hallway and an extract point upstairs. They have explained this was to help balancing the system and for the 'heat grab' upstairs. 

We haven't installed the system yet (awaiting deliveries from BPC and other suppliers), but as vast majority online articles/websites suggest no valves in hallways, we are a bit puzzled.  

I've posted the design drawing here, if you're interested:

 

https://forum.buildhub.org.uk/topic/33106-mvhr-design-help-feedback/#comment-487982

 

[Gone West]

5 hours ago, Ola said:

They have explained this was to help balancing the system

I designed and installed the MVHR system in my last house and I had an outlet in the hall which helped with balancing the system. It's not a problem. Here is the calculation for the house.

 

[Ola]

4 hours ago, Gone West said:

10 hours ago, Ola said:

 

I designed and installed the MVHR system in my last house and I had an outlet in the hall which helped with balancing the system.

@Gone West

Thanks for your input.

In my case, the designer has added one valve each - supply and extract. Would it still help with balancing? In what way?

 

I get @eandg's concern for having stale warm air sitting under the rigde (we have an open ceiling in the upper hallway too), so I'd be actually keen on having these additional valves, providing they don't have a negative impact on the whole system? (For example, drying the air too much)

Could someone kindly explain why MVHR designs don't tend to have valves located in hallways? Is this just a more economical way (because of the cascade ventilation) or are there any other reasons?

[The Reverend]

I'd be interested in the answer too

 

[Gone West]

9 hours ago, Ola said:

In my case, the designer has added one valve each - supply and extract. Would it still help with balancing? In what way?

I don't see how. I have looked at the details on your other thread and both of the BPC configurations look odd to me. I've not seen extracts from bedrooms recommended before. The Paul design looks more conventional. The basic factors are to extract from 'damp' rooms and supply living areas, with the extract and supply being balanced. In a two storey house the hall and landing aren't usually classed as living areas but there is no reason why a supply can't be fitted either to balance the system or because the hall is large and used as a living area, as in my last house.

[Ola]

1 hour ago, Gone West said:

I've not seen extracts from bedrooms recommended before.

No, there are no extracts from bedrooms actually. The BPC have added one extract in the upper hallway and one supply point in the downstairs hall which seem to be a less traditional approach indeed.

 

[Gone West]

2 hours ago, Ola said:

No, there are no extracts from bedrooms actually.

Sorry I was looking at the first BPC description where you have "Upper floor extracts: 2x bathroom, 1x in each bedroom" which was changed to supply in bedrooms in the second BPC description.

[Ola]

@Gone West Thanks for pointing this out! My error, it should be "...supply valves 1x in each bedroom". Sorry for the confusion.