Is constant flow really an optional feature?

[Jolo]

I'm currently researching options to replace my faulty Brink Flair 225, and have found some which apparently don't have constant pressure or constant volume, which seems bizarre to me.

 

So without that basic feature, if I set the normal flow to, say 100 m3/h, it will drift over time as filters become dirty?

 

Here's an example of one: https://www.ventilationland.co.uk/en_GB/p/vent-axia-mvhr-sentinel-kinetic-advance-250sx-including-preheater-right-250m3-h/9985/

 

 

[JohnMo]

39 minutes ago, Jolo said:

if I set the normal flow to, say 100 m3/h, it will drift over time as filters become dirty?

It will vary a little as system pressure drop increases.

Edited 5 hours ago by JohnMo

[Jolo]

Thank you John!

 

So these units are just missing some logic which adjusts the fan speed depending on the pressure, is that right?

 

BTW I was considering getting a Zehnder Q350 with enthalpy exchanger, but then saw it's almost 50kg!! The Duco 325 is only 21kg, that might be a better option... Both seem to have constant flow, at least!

[Alan Ambrose]

Can I ask what went kaput with the old one - I was about to buy one of those.

[Jolo]

3 hours ago, Alan Ambrose said:

Can I ask what went kaput with the old one - I was about to buy one of those.

 

Sure! It never worked properly, as there's a leak inside the unit. This means any smells/moisture are just distributed around the house.

 

I've been posting about it here, hijacking an old thread on the same topic, from about halfway down the first page.

 

The ordeal still isn't quite over, I'm waiting for a collection date and refund at the moment (though the distributor has agreed to this).

 

It's a shame, as I really liked the Flair and chose it after a lot of research, but I can't live with the cooking (and worse!) smells being blown into the bedrooms all the time. (I've been closing the vent into the main bedroom when we cook, the transfer is that strong.)

 

If you decide to go for a Flair anyway then maybe yours will be fine, but I advise you to test it straight away. It's fairly easy to do -- just have someone waft a bag of ground coffee or squeeze the air out of a half-full bottle of shower gel near one of the extract valves, and see if the smell comes through one of the supply valves. I'd be very curious to know if anyone else has the same issue we have!