International technical society.

Provides publications, membership, certified ratings program and seminars for manufacturers of air system equipment including fans, louvers, dampers, air curtains, airflow measurement stations, and acoustic attenuators.

UK-based institution for building services including heating, ventilation and air conditioning.

Nonprofit self-governing technical association dedicated to improvement in technology, design, performance and maintenance of cooling towers. Membership, publications, certification, and meetings.

Site gives details about the organisation including training courses, journals and data manuals.