Fitting an extractor to a boiler lid

[SteveD]

If I'd read this thread earlier I would have asked wether you'd made provision for condensation. What's needed when ducting away steam is a condensation trap to catch any rivulets running back down the duct towards the wort. A circular lipped flange at the bottom of the duct which catches the condensation and a run off pipe would do it. I read about an American brewer who did this when installing a ducting system for the same purpose as you have.

Regarding the fan and the liquid/smells. You probably did, but just in case, did you check that it would be ok to use at near boiling point temperatures as it is situated at the boiler end of the duct and not the exit end as would be ,say, a wall mounted Expelaire?

To avoid the vacuum problem I suppose a 'cooker hood' type arrangement would work, maybe using an oversized lid suspended above the kettle on legs. The fan would pull the steam up even with a gap.....I think.

[Vossy1]

I brewed today at long last

This leads to an update on ducting usage

Be very careful with your calcs on evapouration loss, when using a lid on the copper.

I normally lose about 12% with no lid.

Today I used a lid, but didn't change my formulation in Beersmith. My brewsheet had a boil volume of 59.9ltr based on 46ltr of wort collected.

After the first hour I still had 58 ltr

For the second hour I took the lid off and still had to add 20 min on top to get the SG down to what I was aiming for

On the plus side, I collected 50 ltr of wort instead of the 46 I was targeting, assuming a 80% efficiency

Going to have to adjust the efficiency again me thinks