We have had our new condensation boiler in since mid 2014 and have only just been told by a new plumber that the (reasonably large hall) where it is situated, which includes our main door, does not have enough exterior air flow for the boiler. Extraction is via a chimney to the roof, which had new tubing installed at the same time.
He proposes a 10cm diameter circular hole or a 10cm X 20cm rectangular opening, one at the top of the wall and a second at the bottom. However, I can’t find any information or guidelines on this on the internet. Is it absolutely necessary for functionality or efficiency?
Will these openings not cause quite a draught and therefore heat loss? Are specialist grilles needed for each end?
Also, the wall of this room is quite thick (60cm) so will will need to hire (or almost as cheap to buy) a “carotteuse” drill in order to create a neat circular hole. This also will cost about €150 in addition to any other Equipment required.
All information and advice very welcome! Thanks