Page 65 - 2020 SDCA Project

Mechanical Systems

Heating, Ventilating and Air Conditioning (HVAC) – Most of

the older existing equipment has reached its useful lifespan

and should be replaced (e.g. The Bard units in the south

wing). Some of the rooftop units are newer and might have

some useful service left, but they would need to be

reconfigured in most areas for the new layouts. We

recommend replacing all the existing HVAC systems with
new Variable Refrigerant Flow (VRF) systems. Exceptions

to this would be in the larger volume spaces such as the

Robotics, Makers, Dance, Drama and Theater spaces

where the VRF might not be effective. In those areas, high

efficiency Rooftop units might be the better choice.

VRF works on the same principle that most of our single

family residences use. We are all familiar with the split

systems that have that noisy condensing unit with the big

rotating fan sitting outside which is linked to that indoor air

handling unit that sits in our attic, basement or closet

somewhere in our house and from which extend those
octopus-like ducts into the various rooms. A VRF system

combines one large outside condensing unit (usually much

quieter too) with multiple indoor air handling units. Major

efficiencies are gained because the “smart” units balance

the cooling and heating needs of all the rooms together and

thus require much less energy to operate. They can have

individual air handling units mounted in each room, or they

can also be connected to ductwork to supply more area.

VRF System and Components
SDCA 65