Internal Training Resource

Building Systems Training

Internal Training Hub for Building Engineers

Centralized technical knowledge for HVAC, plumbing, fire protection, and boiler operations. Step-by-step procedures, equipment documentation, and safety protocols for all engineering staff.

SOPs

Operating Procedures

Media

Photos & Videos

Maintenance

PM Checklists

Safety

Compliance Guides

Purpose

Create an internal training website for building engineers that explains and documents all major mechanical systems. The goal is to centralize technical knowledge, improve onboarding, and provide visual and written guides.

Scope

Training materials, SOPs, and system documentation for all engineering staff, supervisors, and contractors. Includes HVAC, plumbing, fire protection, and boiler systems across all managed buildings.

RTU - Rooftop Unit

Rooftop Unit (RTU) Fundamentals

A packaged HVAC system installed on the roof that provides heating, cooling, and ventilation in a single self-contained unit

What is an RTU?

A Rooftop Unit (RTU) is a complete HVAC package that combines heating, cooling, filtration, and ventilation components in one weather-resistant enclosure mounted on a building's roof. RTUs are common in commercial buildings because they save interior space, are easy to service, and can be replaced without disrupting indoor operations.

Cooling Mode

Uses refrigeration cycle to remove heat and humidity from indoor air

Heating Mode

Gas furnace or electric heat strips provide warmth during cold weather

Ventilation

Brings in fresh outdoor air to maintain indoor air quality

Major RTU Components

Compressor

Purpose:

Pumps refrigerant through the system and increases its pressure and temperature

How it works:

  • • Takes low-pressure gas from evaporator
  • • Compresses it into high-pressure hot gas
  • • Sends it to condenser coil
  • • Types: scroll, reciprocating, rotary

Condenser Coil

Purpose:

Releases heat absorbed from indoor air to the outside atmosphere

How it works:

  • • Hot refrigerant gas flows through coil
  • • Condenser fan blows outdoor air across coil
  • • Heat transfers to outdoor air
  • • Refrigerant condenses into liquid

Evaporator Coil

Purpose:

Absorbs heat from indoor air, providing cooling effect

How it works:

  • • Cold refrigerant enters coil
  • • Indoor air blown across cold coil
  • • Refrigerant absorbs heat and evaporates
  • • Cooled air distributed to building

Expansion Valve

Purpose:

Reduces refrigerant pressure and controls flow rate

How it works:

  • • Receives high-pressure liquid refrigerant
  • • Reduces pressure through small orifice
  • • Refrigerant becomes cold low-pressure mix
  • • Regulates superheat for efficiency

Supply Fan/Blower

Purpose:

Moves conditioned air through ductwork to building spaces

How it works:

  • • Draws return air from building
  • • Pushes air through filters and coils
  • • Creates static pressure for distribution
  • • Variable speed for energy efficiency

Gas Furnace/Heat

Purpose:

Provides heating during cold weather operations

How it works:

  • • Burns natural gas in heat exchanger
  • • Blower pushes air over hot exchanger
  • • Heated air sent to building
  • • Some units use electric heat strips

Air Filters

Purpose:

Remove dust, pollen, and contaminants from air

How it works:

  • • Air passes through filter media
  • • Particles trapped in filter material
  • • Protects coils and indoor air quality
  • • MERV ratings indicate efficiency

Economizer Dampers

Purpose:

Brings in free cooling from outdoor air when conditions allow

How it works:

  • • Monitors outdoor air temperature
  • • Opens dampers when outdoor air is cool
  • • Reduces compressor runtime
  • • Saves energy during mild weather

Control Board

Purpose:

Electronic brain that controls all RTU operations

How it works:

  • • Receives signals from thermostat
  • • Sequences heating/cooling stages
  • • Monitors safety switches
  • • Coordinates all component operation

How an RTU Refrigeration Cycle Works

1

Compression

Compressor raises refrigerant pressure and temperature, turning it into hot high-pressure gas

2

Condensation

Hot gas flows through condenser coil, releases heat to outdoor air, and condenses into liquid

3

Expansion

Expansion valve drops pressure rapidly, turning refrigerant into cold low-pressure liquid/vapor mix

4

Evaporation

Cold refrigerant absorbs heat from indoor air in evaporator coil, turning back into gas. Cycle repeats.

HRU - Heat Recovery Unit

Heat Recovery Unit (HRU) Fundamentals

A ventilation device that recovers heat energy from exhaust air to pre-condition incoming fresh air, significantly reducing heating and cooling costs

What is an HRU?

A Heat Recovery Unit transfers thermal energy between two air streams—exhaust air leaving the building and fresh outdoor air entering the building—without mixing them. In winter, warm exhaust air preheats cold incoming air. In summer, cool exhaust air precools hot incoming air. This process dramatically reduces the energy needed to condition ventilation air.

Winter Operation

Warm exhaust air (70°F) transfers heat to cold outdoor air (20°F), raising incoming air temperature to approximately 55-60°F before it enters the building. This reduces heating load significantly.

Summer Operation

Cool exhaust air (72°F) absorbs heat from hot outdoor air (95°F), lowering incoming air temperature to approximately 78-80°F before it enters the building. This reduces cooling load significantly.

HRU Components & Operation

Heat Exchanger Core

Purpose:

Transfers heat between exhaust and supply air streams

Types:

  • Plate Heat Exchanger: Alternating metal plates separate air streams
  • Rotary Heat Wheel: Rotating wheel transfers heat continuously
  • Heat Pipe: Sealed tubes with refrigerant transfer heat

Supply & Exhaust Fans

Purpose:

Move fresh and exhaust air through the heat exchanger

Operation:

  • Supply Fan: Draws outdoor air through heat exchanger into building
  • Exhaust Fan: Pulls stale indoor air through heat exchanger to outdoors
  • Balancing: Fans must be balanced to maintain building pressure

Air Filters

Purpose:

Protect heat exchanger from dust and contaminants

Key Points:

  • • Filters on both supply and exhaust sides
  • • Prevents fouling of heat exchanger
  • • Regular replacement maintains efficiency
  • • MERV 8-13 typical for commercial use
  • • Dirty filters reduce airflow and recovery

Bypass Dampers

Purpose:

Allow air to bypass heat exchanger when recovery not needed

When Used:

  • • Free cooling mode in mild weather
  • • Prevents frost buildup in extreme cold
  • • Allows 100% outdoor air when desired
  • • Protects core from extreme temperatures
  • • Increases system flexibility

HRU Efficiency & Benefits

70-85%

Heat Recovery Efficiency

40-60%

Energy Cost Reduction

2-5

Payback Period (years)

HRUs are essential for meeting modern ventilation requirements while maintaining energy efficiency. Required in many commercial buildings by energy codes like ASHRAE 90.1.

VAV - Variable Air Volume

VAV Box Fundamentals

A terminal unit that varies the amount of conditioned air delivered to a zone based on heating or cooling demand, providing individual zone control and energy savings

What is a VAV Box?

A Variable Air Volume (VAV) box is a zone control device installed in the ductwork that regulates airflow to individual rooms or zones. Unlike constant volume systems that always deliver the same amount of air, VAV boxes adjust airflow based on the zone's temperature needs. When a zone needs more cooling, the VAV box opens to allow more airflow. When the zone is satisfied, it throttles down to minimum airflow, saving fan energy.

Cooling Mode

VAV box damper opens to increase cold airflow when zone temperature rises above setpoint. More cooling = more airflow.

Heating Mode (Reheat VAV)

Damper closes to minimum position and reheat coil (hot water or electric) activates to warm the air when zone needs heat.

VAV Box Components

Damper

Purpose:

Varies airflow by opening or closing

Operation:

  • • Positioned by actuator motor
  • • 0-100% open range
  • • Minimum position for ventilation
  • • Maximum position for peak cooling

Actuator

Purpose:

Motor that physically moves the damper

Types:

  • • Electric actuator (most common)
  • • Pneumatic actuator (older systems)
  • • Controlled by 0-10V or 2-10V signal
  • • Spring return for safety

Airflow Sensor

Purpose:

Measures actual airflow through box

Function:

  • • Uses velocity pressure sensor
  • • Provides feedback to controller
  • • Enables accurate CFM control
  • • Allows airflow balancing

Controller

Purpose:

Manages VAV box operation

Functions:

  • • Reads zone temperature sensor
  • • Modulates damper position
  • • Controls reheat if equipped
  • • Communicates with BAS

Reheat Coil

Purpose:

Heats air when zone requires warmth

Types:

  • • Hot water coil (most efficient)
  • • Electric resistance heat
  • • Activated when damper at minimum
  • • Valve controlled by temperature

Zone Sensor

Purpose:

Monitors space temperature

Details:

  • • Wall-mounted in zone
  • • Sends signal to VAV controller
  • • Some include setpoint adjustment
  • • Critical for proper control

How a VAV System Operates

Cooling Sequence

  1. 1 Zone temperature rises above cooling setpoint (e.g., 74°F)
  2. 2 Controller signals actuator to open damper
  3. 3 More cold air flows into zone
  4. 4 Zone cools down to setpoint
  5. 5 Damper modulates to maintain temperature

Heating Sequence

  1. 1 Zone temperature falls below heating setpoint (e.g., 70°F)
  2. 2 Controller closes damper to minimum airflow position
  3. 3 Reheat valve opens or electric heat energizes
  4. 4 Warm air flows into zone
  5. 5 Zone warms up to setpoint

Energy Savings: By reducing airflow when zones don't need full cooling, VAV systems save 30-50% in fan energy compared to constant volume systems. The AHU supply fan speed slows down as VAV boxes close, reducing overall system energy consumption.

HHP - Heat Pump

Heat Pump Fundamentals

A versatile system that provides both heating and cooling by reversing the refrigeration cycle, moving heat rather than generating it

What is a Heat Pump?

A heat pump is an air conditioning system that can reverse its operation. In cooling mode, it works exactly like an air conditioner—removing heat from inside and rejecting it outside. In heating mode, it reverses the refrigerant flow to extract heat from outdoor air (even cold air contains heat energy) and delivers it indoors. This makes heat pumps much more efficient than electric resistance heating because they move heat rather than create it.

Cooling Mode (Summer)

Indoor coil = evaporator (absorbs heat)

Outdoor coil = condenser (rejects heat)

Result: Cool air indoors, hot air outdoors

Heating Mode (Winter)

Indoor coil = condenser (releases heat)

Outdoor coil = evaporator (absorbs heat)

Result: Warm air indoors, cold air outdoors

Heat Pump Key Components

Reversing Valve

Purpose:

Changes refrigerant flow direction to switch between heating and cooling

Operation:

  • Controlled by solenoid valve
  • Energized in cooling, de-energized in heating (or vice versa)
  • Makes clicking sound when switching modes
  • Critical component unique to heat pumps

Auxiliary/Emergency Heat

Purpose:

Backup heat when outdoor temperature too cold for heat pump efficiency

Types:

  • Auxiliary Heat: Automatically activates below balance point (typically below 35-40°F)
  • Emergency Heat: Manual override that turns off heat pump, uses only backup heat
  • Usually electric resistance heat strips or gas furnace

Defrost Cycle

Purpose:

Removes ice buildup on outdoor coil during heating mode

Process:

  • • Switches to cooling mode temporarily
  • • Hot gas sent to outdoor coil to melt ice
  • • Aux heat runs to keep indoor air warm
  • • Lasts 5-15 minutes
  • • Initiated by temperature/time sensors

Efficiency Benefits

COP (Coefficient of Performance):

For every 1 kW of electricity, heat pump delivers 2-4 kW of heating

Comparison:

  • • Electric resistance: 100% efficient (COP = 1.0)
  • • Heat pump: 200-400% efficient (COP = 2.0-4.0)
  • • Gas furnace: 80-98% efficient
  • • Savings of 30-50% vs electric heat

Heat Pump Performance vs Temperature

Heat pump heating capacity and efficiency decrease as outdoor temperature drops. This is why auxiliary heat is needed in very cold climates.

47°F
Outdoor Temp
100%
Capacity
32°F
Outdoor Temp
75-85%
Capacity
17°F
Outdoor Temp
50-60%
Capacity
0°F
Outdoor Temp
30-40%
Capacity
MDF & IDF

MDF & IDF Network Infrastructure

Main Distribution Frame and Intermediate Distribution Frame—the backbone of building telecommunications and data networking

MDF (Main Distribution Frame)

The MDF is the central hub where all building telecommunications and data services originate. It's the primary connection point between external service providers (ISP, telephone company) and the internal building network.

Key Components:

  • Main Network Switches Core layer switches that route data for entire building
  • Patch Panels Organize and terminate cables from IDFs and external connections
  • Backbone Cabling Fiber optic cables connecting to all IDFs
  • Demarcation Point Where external provider equipment meets building network
  • Servers/Firewalls Network security and management equipment

Location: Usually basement or ground floor for easy provider access

IDF (Intermediate Distribution Frame)

IDFs are satellite communication closets located on each floor or zone of a building. They connect back to the MDF via fiber optic backbone and distribute network services to end users on that floor.

Key Components:

  • Distribution Switches Layer 2/3 switches providing ports for floor devices
  • Patch Panels Terminate horizontal cabling from wall jacks
  • Fiber Uplink High-speed connection back to MDF
  • Cable Management Racks, trays, and labels for organization
  • Power/UPS Backup power for network equipment

Location: One per floor or zone, typically in closet near building core

MDF/IDF Room Requirements

Climate Control

  • • 64-75°F temperature range
  • • 30-55% relative humidity
  • • Dedicated HVAC recommended
  • • 24/7 cooling operation

Electrical Power

  • • Dedicated electrical circuit
  • • UPS battery backup
  • • Sufficient outlets for equipment
  • • Proper grounding required

Security & Access

  • • Restricted access control
  • • Fire suppression system
  • • Water leak detection
  • • Proper cable pathway access
Central Plant

Central Plant Systems

Centralized mechanical equipment that generates heating and cooling for distribution throughout the building via piping systems

Chilled Water System

Produces cold water (typically 42-45°F) for building cooling

Components:
  • Chillers: Generate chilled water using refrigeration
  • Cooling Towers: Reject heat from condenser water to atmosphere
  • Chilled Water Pumps: Circulate cold water to AHUs and fan coils
  • Condenser Water Pumps: Move water between chiller and cooling tower
  • Expansion Tank: Accommodates water thermal expansion
  • Chemical Treatment: Prevents corrosion and scale

Hot Water/Steam System

Produces hot water (140-180°F) or steam for building heating

Components:
  • Boilers: Heat water or generate steam using gas/oil
  • Hot Water Pumps: Distribute heated water to terminal units
  • Heat Exchangers: Transfer heat between systems
  • Expansion Tank: Manages pressure from heating
  • Air Separator: Removes dissolved air from water
  • Make-up Water: Replaces water lost from system

Distribution Piping

Delivers heating/cooling throughout the building

System Types:
  • 2-Pipe System: Single supply and return (heating OR cooling)
  • 4-Pipe System: Separate hot and cold water pipes (simultaneous heating/cooling)
  • Primary/Secondary: Separate plant and building loops for efficiency
  • Variable Flow: VFDs on pumps adjust flow based on demand

BAS Control System

Automated controls manage entire central plant

Functions:
  • Chiller Staging: Turns chillers on/off based on load
  • Reset Schedules: Adjusts temperatures for efficiency
  • Lead-Lag Control: Rotates equipment to balance runtime
  • Alarm Monitoring: Alerts staff to equipment failures
  • Trend Logging: Records data for analysis

Central Plant Advantages

Energy Efficiency

Large equipment operates more efficiently than many small units. Can achieve 20-40% energy savings.

Centralized Maintenance

All major equipment in one location makes servicing easier. Reduces roof access needs and simplifies repairs.

Flexibility & Redundancy

Multiple chillers/boilers provide backup. Can serve addition buildings. Easier to upgrade capacity.

Plumbing Systems

Building Plumbing Fundamentals

Understanding water supply, drainage, and waste systems that provide clean water and remove waste safely from buildings

Water Supply

Brings clean, pressurized water into the building for drinking, washing, and equipment use

Drainage/Waste

Removes wastewater from fixtures and carries it to the sewer system using gravity

Vent System

Allows air into drain pipes to prevent siphoning and maintain proper drainage flow

Water Supply System Components

Main Water Service

Purpose:

Entry point where municipal water enters building

Components:

  • • Water meter measures usage
  • • Main shutoff valve controls flow
  • • Backflow preventer protects supply
  • • Typically 3/4" to 2" diameter

Supply Piping

Purpose:

Distributes water throughout building

Materials:

  • • Copper (Type L or M)
  • • PEX (cross-linked polyethylene)
  • • CPVC (chlorinated PVC)
  • • Galvanized steel (older buildings)

Pressure Reducing Valve

Purpose:

Reduces high street pressure to safe building level

Function:

  • • Protects fixtures and appliances
  • • Typical setting: 50-60 PSI
  • • Required when supply > 80 PSI
  • • Adjustable spring-loaded valve

Water Heater

Purpose:

Heats water for domestic hot water use

Types:

  • • Tank-type (40-80 gallons typical)
  • • Tankless/on-demand
  • • Heat pump water heater
  • • Gas or electric powered

Expansion Tank

Purpose:

Absorbs pressure increase when water heats up

Function:

  • • Prevents excessive pressure
  • • Required in closed systems
  • • Pre-charged with air
  • • Extends water heater life

Fixtures & Valves

Purpose:

End-use devices and flow control

Examples:

  • • Faucets, sinks, toilets, showers
  • • Ball valves (full shutoff)
  • • Gate valves (isolation)
  • • Check valves (one-way flow)

Water Pressure Guidelines

40-45

PSI Minimum

Below this, fixtures may not operate properly

50-60

PSI Ideal Range

Optimal pressure for residential use

70-80

PSI High

Uncomfortable but tolerable, may reduce fixture life

80+

PSI Too High

PRV required, risk of leaks and damage

Drainage, Waste & Vent (DWV) System

How DWV Systems Work

Unlike water supply which uses pressure, drainage systems rely on gravity to move wastewater. All drain pipes slope downward (typically 1/4" per foot) so water flows naturally to the sewer. Vent pipes allow air behind the flowing water, preventing suction that would slow drainage or siphon water out of fixture traps.

Every plumbing fixture has a trap—a U-shaped bend that holds water to block sewer gases from entering the building. The vent system keeps these traps working properly by equalizing pressure.

Fixture Drains

Purpose:

Carry waste from individual fixtures

Details:

  • • Sink drains: 1-1/2" to 2" diameter
  • • Toilet drains: 3" or 4" diameter
  • • Shower/tub drains: 2" diameter
  • • Must slope 1/4" per foot minimum

P-Trap

Purpose:

Holds water to block sewer gas odors

Function:

  • • U-shaped bend under fixture
  • • Maintains 2-4" water seal
  • • Prevents gases from entering building
  • • Required for all fixtures

Vent Pipes

Purpose:

Provides air circulation in drainage system

Function:

  • • Prevents trap siphonage
  • • Allows waste to flow freely
  • • Extends through roof to outdoors
  • • 1-1/2" to 4" diameter typical

Branch Drain Lines

Purpose:

Collect waste from multiple fixtures

Details:

  • • Horizontal pipes collecting drains
  • • Usually 3" or 4" diameter
  • • Connect fixtures to soil stack
  • • Must maintain proper slope

Soil/Waste Stack

Purpose:

Main vertical pipe carrying waste down

Function:

  • • Runs vertically through building
  • • 3" or 4" diameter minimum
  • • Also serves as vent above highest fixture
  • • Connects to building drain at base

Building Drain & Sewer

Purpose:

Final exit of waste from building

Components:

  • • Building drain (inside foundation)
  • • Building sewer (outside to street)
  • • Cleanouts for maintenance access
  • • Slopes toward municipal sewer/septic

Drain Pipe Sizing Guide

1.5"-2"

Lavatory Sink

2"

Shower/Bathtub

3"-4"

Toilet/Water Closet

4"-6"

Main Building Drain

Common Plumbing Problems & Causes

Slow Draining

Causes:

  • • Partial clog (hair, grease, debris)
  • • Improper slope on drain line
  • • Venting issues causing suction
  • • Scale buildup in old pipes

Gurgling Sounds

Causes:

  • • Blocked or inadequate venting
  • • Partial drain blockage
  • • Negative pressure in drain system
  • • Air being pulled through fixture trap

Sewer Odors

Causes:

  • • Dry P-trap (water evaporated)
  • • Cracked or damaged trap
  • • Vent pipe issues or blockage
  • • Missing trap on fixture

Water Hammer

Causes:

  • • High water pressure
  • • Fast-closing valves (quick shutoff)
  • • Missing or failed air chambers
  • • Loose pipes vibrating against framing
Boiler Systems

Commercial Boiler Training

Comprehensive training on commercial and industrial boiler systems, covering operation, maintenance, and safety protocols essential for building engineers.

Inside the industrial boiler room. Heating equipment.

What is a Boiler?

A boiler is a closed vessel that heats water or produces steam by burning fuel or using electricity. The heated water or steam is then circulated through pipes to provide heating or process requirements in a building or facility.

Hot Water
120-200°F
Steam
212°F+
Pressure
0-150 PSI

Common Boiler Types

Fire Tube Boiler

Hot combustion gases pass through tubes surrounded by water. Most common in commercial applications.

Compact design
Lower initial cost
Easy to maintain

Water Tube Boiler

Water flows through tubes heated externally by combustion gases. Used for high pressure applications.

High pressure capability
Greater efficiency
Faster steam generation

Condensing Boiler

Captures latent heat from flue gases. Achieves efficiency ratings up to 98%.

Maximum efficiency
Lower fuel costs
Reduced emissions

Major Boiler Components

Burner Assembly

Mixes fuel and air in proper proportions for efficient combustion.

Heat Exchanger

Transfers heat from combustion gases to water efficiently.

Control System

Monitors and adjusts boiler operation based on demand and safety.

Safety Relief Valve

Prevents dangerous pressure buildup. Required by ASME code.

Feed Water System

Maintains proper water level and quality in the boiler.

Flue/Vent System

Safely removes combustion gases from the building.

Safety & Proper Training

Boiler operation requires specialized knowledge and training. Understanding proper procedures, safety interlocks, and maintenance schedules is critical for safe building operations.

Operation Procedures

Start-up, monitoring, and shutdown sequences

Maintenance

Daily, weekly, monthly, and annual tasks

Code Compliance

ASME, NFPA 85, EPA regulations