The Pam Fan CRF Continuous Running Extractor Fan is a continuously running, low energy, ultra-quiet extract fan for use in kitchens, utility rooms, bathrooms, shower rooms, en-suites and toilets. Unlike conventional intermittent operating extract fans, continuously running extract fans like the Pam Fan CRF Continuous Running Extractor Fan range do not have a high dependency on background ventilators (e.g. trickle vents in windows) to effectively ventilate a dwelling. In more airtight homes, they will generally require fewer background ventilators than intermittent operating fans and in less airtight homes, they are unlikely to require any at all.