Duct locations

[mickeych]

We are working on a large barn conversion and I am struggling to site my MVHR system and particularly the ducting. Is it possible/advisable to site ducting for the MVHR in the floor screed?

Since the building is listed and due to the vaulted nature and exposed beams in the central section, I am struggling to find a route from the plant area at one end of the conversion to the wing at the far end of the conservation (around 40M in distance). 1 possible solution would be to use 2 separate systems 1 in each 'wing' but this appears to be expensive and unnecessary if I can hide the ducting and other pipework under the FFL.

Any ideas keenly considered!

[JohnMo]

Look in to cascade ventilation (passivhaus institute is a good source of info) and coanda effect. You can easily have an outlet one end of a room and the effective ventilation the other end, using coanda nozzles. Two MVHR units work well doesn't have to cost much, just shop around.

[Conor]

A 40m duct run will require some very large diameter ducts. MVHR might not be the right option. 

 

I've two units due to the layout and size of our house. In hindsight would have preferred a single unit and compromised on dropping a ceiling or two to take the extra ducts.

[JohnMo]

This is one of our coanda effect terminals, the air comes out, following the cieling, and drops down around 6 to 7m away. We use them in each bedroom and lounge, cutting the amount of duct required by around 30 to 40m. They are made Zehnder and work really well, they are about 100mm dia.

 

 

 

Below is a plan I got when I was looking at Fresh-r, they proposed two units. The thing to note is how cascade ventilation work, just two supply outlets, one room to room transfer fan, and three extract points.