One of a series of seven articles forming a practical guide to HVAC for museums and historical renovation. Maintains that successfully introducing HVAC systems into historic buildings may be the most challenging aspect of an historic rehabilitation programme. When the building is also used as part of an interpretative museum, it is generally the most controversial. Planning changes to the interior of an historic building requires professionals knowledgeable in multiple disciplines. Notes the need to learn from the active or passive systems used during the construction of the building. Considers the impact of HVAC on the interpretation of the site, the conflict between the climate needs of a collection versus the building and the challenge of hiding systems from sight and minimising impact on the building. Deals with functional considerations for HVAC systems in historic buildings, system selection, making HVAC compatible with the building, and respecting the building structure. Lists guidelines to consider when contemplating HVAC systems for historic buildings.

Article appeared in the Practical Guide to HVAC for Museums and Historic Renovation, which was included with the vol. 41, no. 4, April 1999 issue.