Extraction and options.

[Big Jimbo]

The house i am proposing to build will require 7 extractors. I hated pumping all of that paid for heat out of my last house, and to add i'm not a fan of trickle vents. Would it be possible to have a simple HVMR that had 7 collection points for the stale, moist air, and only Two points where the fresh air could be returned. Say upstairs landing, and downstairs hall ? Would this be a bad idea ? Would i need gaps under all the internal doors ? I'm just trying to consider how many pipe runs i might need, and how feasable that might be. Thanks in advance for any help.

[ProDave]

MVHR is the way to go.

 

Normally it is extract from all "wet" rooms, so kitchen, utility, bathrooms, and fresh air in to bedrooms and living rooms.

[Big Jimbo]

Thanks @ProDave I was hoping that i would be able to keep the pipe runs down to a minimum.

[joe90]

7 minutes ago, Big Jimbo said:

was hoping that i would be able to keep the pipe runs down to a minimum.

That all depends on orientation of the rooms etc, mine was compact and MVHR unit fairly central (in warm roof) &1 to no fans (except in the MVHR).

[Big Jimbo]

@joe90 So my simplified version would'nt cut it ?

[joe90]

1 minute ago, Big Jimbo said:

@joe90 So my simplified version would'nt cut it ?

Sorry just re read it, why 7 extracts and 2 inputs.??. As @ProDave says above extract from wet/damp rooms and input to others so if you’re running 9 pipe runs it does not matter if they are extract or input (except where it meets the manifold. (This presumes you use flexible 70mm or similar pipe which i prefer anyway).

[Big Jimbo]

@joe90I will need 7 extracts 4 bathrooms, kitchen, utility, and downstairs loo. I was hoping that rather than have 7 outputs i could simply have 2. One in the landing upstairs, and 1 in the hall downstairs.

Edited May 5, 2023 by Big Jimbo

[joe90]

5 minutes ago, Big Jimbo said:

4 bathrooms, kitchen, utility, and downstairs loo

Ah!, big house!

[ProDave]

1 hour ago, Big Jimbo said:

@joe90I will need 7 extracts 4 bathrooms, kitchen, utility, and downstairs loo. I was hoping that rather than have 7 outputs i could simply have 2. One in the landing upstairs, and 1 in the hall downstairs.

The point of an inlet in bedrooms and living rooms and gaps under the doors, is fresh air circulates all around the house.  Your proposal would leave stale air in the bedrooms not circulating anywhere and not getting refreshed.

[JohnMo]

6 hours ago, Big Jimbo said:

7 extracts 4 bathrooms, kitchen, utility, and downstairs loo. I was hoping that rather than have 7 outputs i could simply have 2. One in the landing upstairs, and 1 in the hall downstairs.

Interesting I did get a quote for a Dutch system, that had limited inlets, but you have to be clever to ensure you get flow through the dry rooms.

 

For interest I have attached the layout for our house. I didn't go this route in the end but used coanda effect supply nozzles, which does limit the duct lengths considerably.

 

 

[Iceverge]

On 05/05/2023 at 13:51, Big Jimbo said:

was hoping that rather than have 7 outputs i could simply have 2. One in the landing upstairs, and 1 in the hall downstairs

 

It could be done for the living areas where there's plenty of circulation with doors open etc. 

 

However for the bedroom's without ensuites they'll be a ventilation dead end when the doors are closed and would suffer high CO2 levels at night. 

 

Well planned the ducting is quick easy and cheap to install.