Chapter 7 HW Questions - Exam 4

Energy management systems can save an average of about ___% of overall building energy consumption and cut 20-30% off electricity demand costs.

10

Low-temperature water systems have a maximum operating pressure of _______ psi and a maximum temperature of 250 degree's F.

160

Typically buildings with more than ______________ square feet floor area or those with complex HVAC systems are best controlled by BEMS.

25,000

As a rule, all supply and return air ducts and plenums should be insulated with a minimum of R-______ insulation when located in unconditioned spaces.

5

Ductwork located outside of the building envelope should be insulated with a minimum of R-_____ insulation.

8

What ASHRAE standard is for buildings, except low-rise residential buildings?

90.1-1989

High-efficiency particulate arresting (HEPA) filters remove ______% of particles as small as 0.3 microns.

99.7

What controls energy-consuming equipment in a building to make it operate more efficiently while maintaining a comfortable environment. You should list 2 different terms.

A building energy management system (BEMS), A.K.A. building automation system (BAS)

What is the difference between a single duct and a dual duct system?

A dual duct system has a hot deck or hot ductwork and a cold deck or cold duct.

A(n) __________ is a preassembled or site-built equipment device containing coils and fans that is used to condition and circulate air as part of an HVAC system.

AHU

A(n) _________________ is a mechanism that causes a device such as a damper or valve to be adjusted or turned on or off.

Actuator

_________________ fans are propeller-type fans that use a propeller to draw air into the fan and discharge it in the same axial direction: airflow, at all times, from entry to exit is predominantly parallel to the axis of rotation.

Axial

_________________ are used in HVAC systems to allow airflow in one direction and prevent airflow in the opposite direction.

Backdraft Damper

Why wouldn't a system with VAV not shut off 100% of airflow to a room?

Because you would still need some outdoor/fresh air

Describe the purpose of makeup air units (MAU) and where it may be used?

Bringing in fresh air in public places to ensure oxygen levels; typically used in industrial or commercial settings or in once-through, low-flow or primary-secondary commercial HVAC systems.

What is the process called that ensures that all systems are built and function as intended. It usually covers HVAC, electrical, communications, security, and fire management systems and their controls.

Building Commissioning

A ____________________ distribution system is an air-handling configuration that provides a steady airflow into a room or group of rooms while varying the temperature of the air to meet heating and cooling demands.

CAV - Constant Air Volume

A(n) ________________ is a factory-made assembly that uses special design and construction features that provide unusually quiet operation. Terminals of this type are used in broadcast studios, libraries, and other applications where a minimum-noise, premium-quality terminal is required.

CV - Constant Volume

A very good method of providing occupancy-based ventilation control is to use a _____________.

Carbon Dioxide sensor

A ________________ fan is a fan in which the air is turned from parallel to the axis of rotation on entry to a direction tangential to the arc described by the tips of the rotating blades or vanes. It is also known as a squirrel cage fan.

Centrifugal

A cooling coil has what liquid medium within it?

Chilled water coming from the chiller

A _____________ consists of a network of tubes in which a hot or cold fluid such as water is circulated.

Coil

What must be provided to remove condensation that is formed during the cooling process on cooling equipment?

Condensate Drain

A(n) ________________ is a heating distribution device that is constructed of one or more finned tubes that carry steam or hot water and that transfer heat by circulation of air (natural convection).

Convector

Cooling coils that have refrigerant are also termed _____________ coils.

DX

A _____________ is an airflow control device used in ductwork to vary the volume of air passing through an air outlet, air inlet, or duct.

Damper

A(n) _________________ are supply outlets of an air distribution (duct) system with built-in louvers or deflection devices that throw and disperse air to promote good air circulation and temperature equalization in the conditioned space.

Diffuser

The electric motor that runs most HVAC fans is called a __________.

Drive

__________ is a hollow pipe or conduit that conveys and transfers air in a heating, ventilating, and cooling system.

Duct

________________ is a thick adhesive that is applied to ductwork joints to fill gaps and it dries to a soft solid state.

Duct Mastic

Heating equipment has the heat it produces distributed primarily by the use of one or combinations of four types of distribution. List the 4 types of heat distribution methods.

Duct, natural heat transfer (natural convection), Heating coils, Individual space heaters.

Cooling equipment has the cooling effect it produces distributed primarily by the use of one or more combinations of three types of distribution systems. List the 3 types of cooling distribution systems.

Ducts, cooling coils, individual air conditioning systems.

A duct system, frequently called ______________, is a network of ducts that confines and channels air and serves as the distribution system in a heating, ventilating, and cooling air system.

Ductwork

A(n) _______________ is designed into a building's air-handling system to cool with outside air instead of using air conditioning equipment to cool indoor air.

Economizer

Air cleaners are classified by the size and thickness and system they work with

False

Axial fans have more mass farther from the axle, which requires more starting torque, but they are generally quieter than centrifugal.

False

Chilled beam systems are stand-alone systems that do not receive ventilation air

False

Dual duct systems are more efficient because of leakage of warm air from the hot duct, which provides additional load to the space.

False

Duct tape is acceptable for a duct sealing process.

False

During the cooling cycle, a VAV fan remains on to ensure cool air gets to the conditioned space.

False

Outside air supply ducts located outside of the building envelope are required to be insulated with an minimum R-4 insulation.

False

The longitudinal joints are the only joints that are required to be fastened and sealed.

False

Thermostats can be mounted on any wall as long as it is inside the envelope of the structure?

False

Thermostats used for hot water systems are usually only the day-night type thermostat.

False

A(n) ________________ is a mechanical device that uses rotating airfoil blades or vanes to continuously move air.

Fan

A(n) ________________ provides heating/and or cooling by circulating steam, hot water, or chilled water piped in from a central plant. It consists of a filter, fan(s), and separate hot water and chilled water coils or a single water coil that may be used for both functions. It can be hidden behind the wall or ceiling or located directly in the room.

Fan Coil Unit (FCU)

A(n) _______________ is located in the HVAC ductwork and automatically closes to obstruct smoke and fire from the building blaze.

Fire Damper

_______________ type ductwork is typically used to connect diffusers, mixing boxes and other terminals.

Flexible

_______________ have sets of vertical and horizontal vanes that deflect the air stream vertically and horizontally. On the return type, the vanes are typically fixed.

Grille

The purpose of using a heating coil is to:

Heat the airstream that is going over the coil to carry heat to the conditioned space.

A(n) _______________ is a heating distribution device that transfers heat from steam or hot water by radiation to objects within visible range and by conduction to the surrounding air that, in turn, is circulated by natural convection.

Radiator

A(n) _______________ is a grilled equipped with a built in damper.

Register

What are perimeter zones?

Rooms and spaces with at least one exterior wall

The least costly system within the CAV and VAV system is the _______________.

Single Duct

What type filters reduce the level of sound moving through the ductwork

Sound-attenuating

TAB stands for?

Testing Adjusting and Balancing

What are Mechanical Codes?

They are a set of standards adopted into law by local governmental entities to regulate mechanical systems and equipment including HVAC, exhaust systems, chimneys and vents, ducts, appliances, boilers, water heaters, refrigeration, hydronic piping, and solar systems

A day-night thermostat permits the setting of one temperature for the daytime and another lower for nighttime.

True

A method to provide zone control on a single HVAC system is by dividing the building into zones that are served by a single HVAC distribution system. Each zone has its own sensors and controls.

True

All-water HVAC systems heat and cool by circulating hot water from a boiler or chilled water from a chiller through a finned coil in a fan-coil unit or unit ventilator in the space.

True

Balance dampers are not intended to be used in applications as a positive shutoff or automatic control damper.

True

Coil selection is based on the amount of sensible or latent heat that must be transferred to the airstream; the design conditions of air entering and leaving the coil; coil construction, water or refrigerant velocity; and face velocity of the airstream.

True

Fans in unit ventilator cabinets draw recirculated air from the room and ventilation air from the outdoors through louvers on an exterior wall.

True

Insulation is generally not required for duct when the design temperature difference between the interior and exterior of the duct or plenum does not exceed 15 degrees F.

True

The effectiveness of air cleaners in removing pollutants from the air depends on both the efficiency of the device itself, and the amount of air handled by the device.

True

There are two primary configurations of air distribution systems (excluding packaged units): constant air volume (CAV or CV) systems and variable air volume (VAV) systems.

True

WHLP systems saves energy by transferring excess heat from one zone to a zone requiring heat.

True

You should keep a thermostat from the cold air drafts, away from any possible warm air drafts, and away from any direct sunlight.

True

__________________ are used in duct bends and elbows to effectively direct the airflow through the turn or bend.

Turning Vanes

A(n) _________________ is a type of unit that has the capacity to introduce ventilation(outdoor) air into a room in addition to being able to provide space cooling and/or heating. It is a type of fan-coil unit.

Unit Ventilator

A __________________ distribution system is an air-handling configuration that holds supply air to a constant temperature and controls temperature within a space by variant the quantity of supply air.

VAV

_______________ are used to control the flow of water and liquid through a hydronic distribution system.

Valves

The piece of equipment that adjusts the rotational speed of the electric motor so that it closely corresponds to the varying heating and cooling load requirements is called the ____________.

Variable-Frequency Drive

A(n) _______________ is an area of a building, such as a single room or set of rooms, that has thermal and/or humidity requirements requiring separate control.

Zone

What type of a control uses compressed air to control equipment?

Pneumatic Control

What type thermostat can be used in your home to match the temperature set points with the timing of your space needs?

Programmable

A(n) ______________ is a mechanical device used to compress a liquid or drive flow in a fluid. They are typically driven by an electric motor.

Pump

A(n) _________________ is a factory-made assembly that has hot water or steam reheat coils or electric-resistance heaters within the box. This type of device can increase the temperature of the airstream by reheating it before it enters a space that does not need the desired cooling.

RH - Reheat Terminal

The ICC (International Code Council, wrote what standard for mechanical systems?

IMC

A(n) _________________ is a shutter-like device with fixed slats or vanes that are angled to admit or release air, to provide privacy, and to keep out rain and noise.

Louvers

A(n) _____________ is an air handling unit that conditions 100% outside air

MAU

A ________________ generally consists of a sheet metal (or similar material) flap, shaped to fit the inside of a round or rectangular duct. By rotating a handle located outside the duct, a technician can adjust air flow to match the needs of a particular zone or room.

Manual Damper

______________ is a network of ducts and fans that introduce outdoor air into a building.

Mechanical Ventilation