3% OF ANNUAL

TOTAL

Summer Cooling
Existing Buildings

With and Without Extra Cost

Opening Statement

Use of summer cooling systems provides a worthwhile investment both in dollars and in energy for improvement

in working conditions and quality of life which is not subject to debate because of the current recognition of energy utilization concern. The need, however, is evident to reduce the energy consumption to provide summer cooling, by improving the energy performance of cooling systems, by reducing the loads imposed on cooling systems, and by conscientiously reassessing the levels of cooling needs. The total use of energy for cooling will continue to increase - our objective is to reduce the relative requirement for each essential cooling system, existing or new, in order that the service rendered by such systems will continue to serve people. Even though the energy used for residential and commercial summer cooling is less than 3 percent of the national annual total it is 42 percent of the summer total for these types. of buildings, and it does represent an annual national energy expenditure of more than 1.5 x 1015 Btu* (in 1968 and increasing at 10 percent per year) If it is assumed that wasteful cooling system practices can be improved by implementation of the techniques to the extent presented here, then it is reasonable to expect that the energy requirement can be reduced as much as 30 percent over present rates,

1/

Patterns of Energy Consumption in the United States.

in many cases without sacrificial reduction of needed performance. In many cases the actual performance of systems can be improved at the same time that both dollar cost and energy cost is lowered. Some of the suggestions to be made in our presentation today can be implemented with little or no cost. Others would require investment of materials or equipment and labor. Not all of these modifications have had broad experience because traditionally buildings have been constructed with primary concern for first cost, and some of the devices may not have an early payback in dollars although they can be expected to accomplish the energy reduction tasks. It is our hope that the necessary field and laboratory work will be done to evaluate these suggestions and determine other means to conserve our valuable energy resources.

Many of the suggestions for reworking existing systems and designing new systems can best be utilized by considering the investigation of all elements. This integrated design

can best be done by professional engineers, architects and

designers.

Summer Cooling
Existing Buildings
No Extra Cost

o Reduce use of cooling systems

Turn off cooling systems not actually needed for people or essential processes. Many cooling systems either in total or in part provide cooling in spaces which do not need cooling. These could be eliminated with little or no sacrifice.

Examples

of these areas are entrances, halls, storerooms and other such spaces which people use either infrequently or for only short eriods.

Turn off cooling systems at all times when spaces are noccupied. Many spaces are unnecessarily cooled continuous ly hroughout periods of non-occupancy, for example homes and partments unoccupied all day, meeting rooms, auditoriums, etc. nich are used only occasionally. If cooling cannot be turned ff completely during periods of non-occupancy, set thermostats and humidistats) at the highest setting on the controls.

Turn off cooling systems in parts of buildings not in e. To facilitate this many buildings could have the occupancy hedules arranged to group light load uses in one wing, or on e floor rather than scattered throughout the entire building. The energy reduction to be obtained by turning off systems 11, of course, be determined by the extent to which these eps apply to a particular building. It is estimated that, the average, this could reduce energy usage by 5 to 10 percent.

o Raise thermostat and humidistat settings

Thermostat settings of 75°F or lower are not uncommon, in

In

fact, may be prevalent, for summer cooling operation. systems with humidity control space humidity of 50% is a customary design. Recent studies show that, with suitable clothing, temperatures approaching 80°F and humidities approaching 60% R.H. may be acceptable.

Raising thermostat settings to 80°F and humidistat settings to 60% R.H. could reduce energy demand by an estimated 15% compared with operation at 75°F and 50% R.H. (Note: In some reheat systems internal operating temperatures must also be raised, along with thermostat settings, to effect the desired energy savings.)

Many systems because of poor zoning, poor distribution, improper location of controls, or improper control function, may actually operate at temperatures below desired levels. Adjusting and balancing such systems will reduce the energy requirement to the extent that overcooling is eliminated.

Humidity controlling systems, particularly those which use reheat, present opportunity to reduce energy usage by raising the humidistat to the highest acceptable setting. These systems operate to control humidity by cooling the air to remove moisture, then reheating as necessary to maintain the desired room temperature. Most of these systems use "new" energy such as electricity, steam or hot water for the reheating operation.