Continuously Extract hob connected to HRU?

[estebanvmeo]

I would like to install an Extract hob within the kitchen. As per F document of Building Regulations, the intermittent extract rate is 30l/s (is going to be close to the hob) or 13l/s if is continuous extraction.

If we are going to install a HRU for the ventilation for the whole floor, is there any chance to connect the extract hob with intermittent extract rate to the HRU system (continuous extraction)? Or does it have to be connected to an extract fan not linked to the HRU system?

Thanks in advance
Vic

 

[John D v2.0]

You can't put two fans in series in the same duct. If you're blowing 30 litres from the kitchen then some of that will go into the other rooms.
You either need your hru to take the lower rate all the time, or have a separate intermittent fan to take it out of a separate duct.
As a related note there is often debate about whether it's a good idea to extract cooking fumes through a heat exchanger from a cleaning point of view.

 

[estebanvmeo]

Thanks John