TABLE OF CONTENTS This chapter was contributed by Allan Daly.
This chapter discusses a range of system design solutions for perimeter and other special zones.
Perimeter systems serve a number of functions in commercial buildings. These include the following.
Local Heating. Almost all commercial buildings require heat at the perimeter due to the influence of the building envelope. At the same time, this heating demand is often intermittent and during swing seasons can happen early in the same day that cooling is required later.
Local Cooling. Perimeter systems are designed to allow wide variation in the amount of cooling that can be provided to a zone to deal with dynamic solar and other envelope loads. The more efficient the envelope that a building has, the more options that are available for perimeter cooling systems.
Interior / Perimeter Separation. The perimeter space is defined as the space in a system that is affected by weather and outside conditions. Perimeter systems allow the perimeter to be separated from the interior system to prevent "fighting" in winter. This is a requirement of virtually all energy codes.
Automatic Control. Because of the dynamic nature of perimeter building loads, an important function of perimeter systems is to provide automatic control that can adjust to varying interior conditions. Envelope and other perimeter loads change too quickly and constantly to make manual control an effective option.
The two- or four-pipe constant-speed...
