interior’s guidelines have been on the books for over fifty years; they state that historic build- ings must be preserved—and preserved in a respectful way. These philosophies have always embraced sustainability by their focus on saving existing materials rather than discarding them and putting back new materials.
As mechanical engineers, we look at statistical weather data to determine the heating and cooling loads imposed on the buildings we design. The weather data we use most are pub- lished by ASHRAE; they consist of a rolling thirty-year average of weather conditions. In re- viewing this weather data—published in 1950 and 1980 and again in 2005—I have seen no changes in temperature conditions or rainfall averages. However, data being published relating to airborne pollutants reveal a serious concern.
Imagine a 1ºC increase in these thirty-year average conditions globally. Scientists are now pre- dicting enormous ecological changes. But what would we see happening in our small corner of the world of preservation? From a climate control systems design standpoint, a 1ºC change in outdoor weather is insignificant to a modern well-financed museum that has complete year- round precision heating, ventilating, and air-conditioning (HVAC) systems. Yet other, less- financed facilities do not have the luxury of substantial budgets and precision heating and cooling systems to achieve year-round constant climate control. From our work in historic buildings of institutions in the heating climates of North America, we usually see heating sys- tems installed, but cooling systems are not the norm. For cooling, at best we will find one or two small window air conditioners located in the staff office and sometimes in a small storage room.
Conrad Climate Control Systems Design and Climate Change Contribution to the Experts’ Roundtable on Sustainable Climate Management Strategies, held in April 2007, in Tenerife, Spain