Joined: 22 May 2005 Posts: 342 Location: West Devon
Posted: Wed Oct 30, 13 12:08 pm Post subject: Positive pressure ventilation? Heat recovery?
Just as an experiment, small scale and cheap I hope.... Air vent /extract fan from bathroom will be via about 4m of rigid tube (with a slight downward slant to clear condensation) through attic space and out through a gable end wall. At the same time I'd like to try positive pressure ventilation into the main bedroom (Via low power fan) to reduce condensation. Am I likely to gain significant heat with a long concentric heat exchanger on the extract fan tube? Either a 2 inch air tube inside a 6 inch extract pipe or a 6 inch jacket on a 4 inch extract pipe. Cheap plastic or light metal ducting - whatever I can find.
Extract fan to be a standard bathroom duct fan (or maybe a two-speed fan). Positive pressure vent fan maybe a computer cooling fan? Air intake for positive pressure system through a muslin or foam filter in the loft space.
Comments? design or material suggestions? experiences?
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