Unit 79

The amount of outside air introduced can be controlled using

A CO2 sensor

Which part of a large office building generally requires cooling all year, even when it is cold outside?

Core

Which of the following statements is most accurate? A. Core systems must adjust to accommodate variables such as wind effects. B. Core systems are subject to a wider range of variables than perimeter systems. C. Perimeter systems only need to accommodate loads such as electrical equipment and lighting. D. Perimeter systems accommodate many of the loads of the core system and loads caused by weather.

D. Perimeter systems accommodate many of the loads of the core system and loads caused by weather.

In perimeter applications using the variable-air-volume system, the primary air handler provides

Variable volume and constant temperature

A single-zone, constant-air-volume system is best suited for conditioning

a building's core area

Outside air is drawn into the building through

an outside air damper

How does an energy-recovery wheel improve system efficiency?

by transferring heat between the ventilation air and the exhaust air

Constant-air-volume systems can deliver different levels of heating and cooling

by using variable-air-volume mixing boxes

A unique feature of multizone and double-duct systems is that they

can heat and cool at the same time using a single air handler

In the event of a fire, fire dampers prevent oxygen from feeding the fire by

closing off the outside air supply completely

In multizone systems with one trunk duct to each zone, what is used to adjust the temperature of the air?

hot and cold decks

In a single-zone, constant-volume system, which floors only have provisions for cooling?

intermediate floors

The perimeter system is often used alongside a core system in

larger buildings

Under normal operations, some outside air will always be included to

prevent excessive levels of CO2 from building up

A multizone system allows a wide range of temperatures in different zones supplied by a single unit by

providing a blend of always-available heated and cooled air to any zone

In a single-zone, constant-air-volume system, the amount of air moving through the air handler

stays the same all the time

The perimeter of a large multistory high-rise building consists of

the areas around the outside of the building

How does an energy-recovery wheel transfer latent heat between the ventilation and exhaust air?

the desiccant in the wheel absorbs the moisture in the air

When a VAV box on a constant-air-volume system throttles air into the conditioned area

the excess air dumps into the area above the ceiling

The core of a large multistory high-rise building consists of

the interior areas

What is the purpose of the hot and cold decks on a multizone system?

they provide simultaneous hot and cold air

Why would a preheat coil be used on the energy-recovery wheel?

to prevent frost from forming on the wheel