Ace MEP Exam 2: Focused Study and Practice Guide
Benefits of using a Central HVAC System - correct answer ✔✔-Higher quality, efficiency, and durability
standards
-Indiv units are going to work better than packaged units
-Maintenance in concentrated (one location to fix problem)
Split System HVAC - correct answer ✔✔Type of system that lasts 15-16 years, potentially up to 20 years
Packaged HVAC Units - correct answer ✔✔10-15 years
"Concentration" for maintenance of Central HVAC - correct answer ✔✔-Noise is removed from the zone
-Diversity allows for lower installed capacity
-Can use thermal storage
TU thermal storage tank - correct answer ✔✔-5 million gallons
-Gets filled at night by the chillers to supply the campus throughout the the day
The electrical cost is lower at night (aka demand charge) - correct answer ✔✔Why is the TU thermal
storage tank filled at night rather than the day?
Benefits of using Distributed HVAC - correct answer ✔✔-Easy to provide zoning
-Offers direct control by occupants ensuring optimal comfort
-Independent scheduling is useful for energy savings
-Lower capital costs and a shorter lead time for equipment
-No need for dedicated maintenance staff (use service contract)
-Can often be installed on the roof where there is more useable space for the interior
,Air output points can be controlled - correct answer ✔✔Why is it easy to provide zoning in a Distributed
HVAC System?
Constant Air Volume System (CAV) - correct answer ✔✔-Provide steady zone airflow that is at design
year round
-Meet varying loads with varying varying supply air temperature
-More common in old buildings
Variable Air Volume System (VAV) - correct answer ✔✔Provide constant zone supply are temperature
that meet varying loads with varying supply airflow
VAV system - correct answer ✔✔What type of system allows the fan to meet the load and therefore
saves electrical power?
Variable Frequency Drive (VFD) - correct answer ✔✔Drives the fan in a VAV system and provides energy
savings from 35 to 65 percent over conventional constant speed applications
Variable Speed Drive (VSD) - correct answer ✔✔-Allows for control of the speed of electric motors so
that fans and pumps do not run at full load
-The output of those pumps and fans will always meet the current demand
Variable Speed Drive (VSD) - correct answer ✔✔This is a type of adjustable-speed drive used in electro-
mechanical drive systems to control AC motor speed and torque by varying motor input frequency and
voltage.
This helps reduce energy consumption by up to 60 percent
Dual Duct System (DD) - correct answer ✔✔Type of system in which the air-handling unit has two coils: a
cooling coil and a heating colt, both of which operate continuously
Dual Duct System - correct answer ✔✔-24/7, the coils feed cool or hot air into designated ducts (cold
deck and hot deck)
, -The two ducts run parallel to each other throughout the entire building
Multizone System (MZ) - correct answer ✔✔-Bypass for air to go around coil instead of through it
-Control relative humidity
-Each zone has its own damper to control flow
Multizone System (MZ) - correct answer ✔✔-Hot and cold air is mixed for each zone at the air handler
-Not efficient
Air Water Systems - correct answer ✔✔Type of system:
-Use a combination of conditioned air and zone water coils
-Ventilation requires outdoor air and zone heating and cooling can be met with fan coils
-Typically used in small areas
Two Pipe Fan Coil - correct answer ✔✔What type of fan coil is just for heating OR cooling, but not both?
Four Pipe Fan Coil - correct answer ✔✔What type of fan coil is used for both heating AND cooling?
Fan Coil - correct answer ✔✔-Fan blows air across the coil
-Two Pipe and Four Pipe
-Two Pipe: supply and return
-Four Pipe: hot and cold, supply and return
Fan Coil - correct answer ✔✔-Something providing heating and cooling
-Boiler and chiller
Secondary HVAC Equipment and Systems - correct answer ✔✔-Can generally be found inside the
building
Benefits of using a Central HVAC System - correct answer ✔✔-Higher quality, efficiency, and durability
standards
-Indiv units are going to work better than packaged units
-Maintenance in concentrated (one location to fix problem)
Split System HVAC - correct answer ✔✔Type of system that lasts 15-16 years, potentially up to 20 years
Packaged HVAC Units - correct answer ✔✔10-15 years
"Concentration" for maintenance of Central HVAC - correct answer ✔✔-Noise is removed from the zone
-Diversity allows for lower installed capacity
-Can use thermal storage
TU thermal storage tank - correct answer ✔✔-5 million gallons
-Gets filled at night by the chillers to supply the campus throughout the the day
The electrical cost is lower at night (aka demand charge) - correct answer ✔✔Why is the TU thermal
storage tank filled at night rather than the day?
Benefits of using Distributed HVAC - correct answer ✔✔-Easy to provide zoning
-Offers direct control by occupants ensuring optimal comfort
-Independent scheduling is useful for energy savings
-Lower capital costs and a shorter lead time for equipment
-No need for dedicated maintenance staff (use service contract)
-Can often be installed on the roof where there is more useable space for the interior
,Air output points can be controlled - correct answer ✔✔Why is it easy to provide zoning in a Distributed
HVAC System?
Constant Air Volume System (CAV) - correct answer ✔✔-Provide steady zone airflow that is at design
year round
-Meet varying loads with varying varying supply air temperature
-More common in old buildings
Variable Air Volume System (VAV) - correct answer ✔✔Provide constant zone supply are temperature
that meet varying loads with varying supply airflow
VAV system - correct answer ✔✔What type of system allows the fan to meet the load and therefore
saves electrical power?
Variable Frequency Drive (VFD) - correct answer ✔✔Drives the fan in a VAV system and provides energy
savings from 35 to 65 percent over conventional constant speed applications
Variable Speed Drive (VSD) - correct answer ✔✔-Allows for control of the speed of electric motors so
that fans and pumps do not run at full load
-The output of those pumps and fans will always meet the current demand
Variable Speed Drive (VSD) - correct answer ✔✔This is a type of adjustable-speed drive used in electro-
mechanical drive systems to control AC motor speed and torque by varying motor input frequency and
voltage.
This helps reduce energy consumption by up to 60 percent
Dual Duct System (DD) - correct answer ✔✔Type of system in which the air-handling unit has two coils: a
cooling coil and a heating colt, both of which operate continuously
Dual Duct System - correct answer ✔✔-24/7, the coils feed cool or hot air into designated ducts (cold
deck and hot deck)
, -The two ducts run parallel to each other throughout the entire building
Multizone System (MZ) - correct answer ✔✔-Bypass for air to go around coil instead of through it
-Control relative humidity
-Each zone has its own damper to control flow
Multizone System (MZ) - correct answer ✔✔-Hot and cold air is mixed for each zone at the air handler
-Not efficient
Air Water Systems - correct answer ✔✔Type of system:
-Use a combination of conditioned air and zone water coils
-Ventilation requires outdoor air and zone heating and cooling can be met with fan coils
-Typically used in small areas
Two Pipe Fan Coil - correct answer ✔✔What type of fan coil is just for heating OR cooling, but not both?
Four Pipe Fan Coil - correct answer ✔✔What type of fan coil is used for both heating AND cooling?
Fan Coil - correct answer ✔✔-Fan blows air across the coil
-Two Pipe and Four Pipe
-Two Pipe: supply and return
-Four Pipe: hot and cold, supply and return
Fan Coil - correct answer ✔✔-Something providing heating and cooling
-Boiler and chiller
Secondary HVAC Equipment and Systems - correct answer ✔✔-Can generally be found inside the
building
