scope:

INTRODUCTION

The primary purpose of museums Heating Ventilation and Air Conditioning (HVAC) system is to establish and maintain pre-determined environmental conditions within the building. There are two conditions that govern the interior environment within the building:

The first is to ensure that the temperature and humidity conditions maintained in the building are correct for the preservation of the artwork to be exhibited or stored.

The second is to create an environment that is satisfactory for the visiting public.

The proper HVAC system for the protection of the exhibits must address these two key items, minimize the effect that changes in the outside environment will have on the interior of the building and assure that specified interior conditions are maintained at all times.

To protect the building from being influenced by outside climactic conditions, the building envelope (walls, roof, and windows) must be carefully designed and constructed to minimize the effect of changes in weather and climate on the interior of the building, particularly in areas where sensitive works of art are displayed or stored. This would include thermal performance as well as the porosity or air tightness of the building.

Maintenance of the proper interior environment is the function of the HVAC system design. This system is designed to provide a controlled temperature and humidity throughout the year 24 hours each day in the exhibit and storage areas.

The building environment is monitored and controlled by a central computerized Building Management System (BMS). The BMS system will monitor and report on all aspects of the operation and automatically create maintenance and trouble shooting documents to alert the operating staff of actions to be taken to correct an improper environmental condition in the building.

The air handling systems will transmit heating and cooling from the boiler and refrigeration plant to the various spaces in the building in a manner that will ensure a clean environment with the temperature and humidity controlled at all times, using air as the transfer medium.

For the galleries a variable volume, variable temperature air supply system together with a radiant floor for heating and cooling will be utilized. The air handling system will be separate from the non critical areas of the building. It will therefore be possible to operate and occupy administrative, storage, restoration and other support areas separate from exhibit areas utilizing variable air volume systems for energy efficiency.

Simmonds (1994) reported on using radiant floors for both heating and cooling to condition museum spaces. Akron Art Museum and the Water and Life Museum in Hemet, California have been successfully conditioned in the same manner.

The same principles have been used in these designs with the exception of the perimeter air supply.

With the advances in simulation programs which permit detailed analysis of the indoor environment, the individual elements necessary for the creation of a comfortable indoor climate can be analyzed and optimized. Using the predicted mean vote as determined by Fanger (1972), radiant heat exchange can be studied. Since each individual surface temperature and its relationship (i.e. position to the other surfaces) can be determined, a solution to the comfort balance equation can easily be found.

When incorporating a radiant system and a variable volume ventilating system, the ventilation system may only be dimensioned to supply of outdoor air for each person and to remove the latent as well as the material heat load if a radiant system selected to remove the remaining cooling loads. Simmonds (1993,1994,2003) has reported on these designs and their effectiveness in providing optimal climate and comfort.

Borressen (1994) and Simmonds, Gaw, Holst and Reuss (2000) have shown that radiant cooled floors are capable of removing up to 85 w/m2 (30 BTUH/sf) of energy from a space by the combination of 35m/w2 (12 BTU/sf) by convection and 50 w/m2 (17 BTUH/sf) by solar absorption. Many papers have been written on the performance of radiant floor for heating Maccluer, Athienitis, Simmonds, Olesen, Meirhans have reported on the performance of active concrete systems.