Here is some advice from ACRE
Air blown and fan heaters – Questions have been asked about whether these should be used. When it comes to cold weather the hall will need a working heating system and replacing it would be a major capital item, so such systems will need to be used. It might help to think about the risk. Hopefully, this will provide some reassurance:
• The Government guidance not to use hot air hand dryers was withdrawn (as reflected in the second version of the ACRE Information Sheet).
• In response to previous queries about this, attention was drawn to buildings guidance which indicated that risk could be relatively low because it would require an infected person to be near the air intake for the virus to be transmitted via the heating (or ventilation) system. A similar principle may well apply with fan heaters. If the air intake is outside the building (i.e. 100% fresh air), this is less of a risk.
• The Government Sports guidance on energetic exercise (e.g. Zumba) requires 100% fresh air ventilation because droplet transmission is more of a risk with energetic activity. So, the context of sedate and now socially distanced activities, village and community halls should be lower risk.
• If the air intake is indoors and the committee are worried, rather than replacing the heating, it would probably be more cost-effective not to host Zumba or similar energetic indoor sports until the risk level has further reduced to a point where all indoor activity without social distancing is again allowed.