Inspection

OUTDOOR AIR INTAKES

Marked locations of all outdoor air intakes on a small floor plan (for example, a fire escape floor plan)

Ensured that the ventilation system was on and operating in “occupied” mode

OBSTRUCTIONS

Ensured that outdoor air intakes are clear of obstructions, debris, clogs, or covers

Installed corrective devices as necessary (e.g., if snowdrifts or leaves frequently block an intake)

POLLUTANT SOURCES

Checked ground-level intakes for pollutant sources (dumpsters, loading docks, and bus-idling areas)

Checked rooftop intakes for pollutant sources (plumbing vents; kitchen, toilet, or laboratory exhaust fans; puddles; and mist from air-conditioning cooling towers)

Resolved any problems with pollutant sources located near outdoor air intakes (e.g., relocated dumpster or extended exhaust pipe)

AIRFLOW

Obtained chemical smoke (or a small piece of tissue paper or light plastic)

Confirmed that outdoor air is entering the intake appropriately

SYSTEM CLEANLINESS
AIR FILTERS

Replaced filters per maintenance schedule

Shut off ventilation system fans while replacing filters (prevents dirt from blowing downstream)

Vacuumed filter areas before installing new filters

Confirmed proper fit of filters to prevent air from bypassing (flowing around) the air filter

Confirmed proper installation of filters (correct direction for airflow)

DRAIN PANS

Ensured that drain pans slant toward the drain (to prevent water from accumulating)

Cleaned drain pans

Checked drain pans for mold and mildew

COILS

Ensured that heating and cooling coils are clean

AIR-HANDLING UNITS, UNIT VENTILATORS

Ensured that the interior of air-handling unit(s) or unit ventilator (air-mixing chamber and fan blades) is clean

Ensured that ducts are clean

MECHANICAL ROOMS

Checked mechanical room for unsanitary conditions, leaks, and spills

Ensured that mechanical rooms and air-mixing chambers are free of trash, chemical products, and supplies

CONTROLS FOR OUTDOOR AIR SUPPLY

Ensured that air dampers are at least partially open (minimum position)

Ensured that minimum position provides adequate outdoor air for occupants

CONTROLS INFORMATION

Obtained and reviewed all design inside/outside temperature and humidity requirements, controls specifications, as-built mechanical drawings, and controls operations manuals (often uniquely designed)

CLOCKS, TIMERS, SWITCHES

Turned summer-winter switches to the correct position

Set time clocks appropriately

Ensured that settings fit the actual schedule of building use (including night/weekend use)

CONTROL COMPONENTS

Ensured appropriate system pressure by testing line pressure at both the occupied (day) setting and the unoccupied (night) setting

Checked that the line dryer prevents moisture buildup

Replaced control system filters at the compressor inlet based on the compressor manufacturer’s recommendation (for example, when you blow down the tank)

Set the line pressure at each thermostat and damper actuator at the proper level (no leakage or obstructions)

OUTDOOR AIR DAMPERS

Ensured that the outdoor air damper is visible for inspection

Ensured that the recirculating relief and/or exhaust dampers are visible for inspection

Ensured that air temperature in the indoor area(s) served by each outdoor air damper is within the normal operating range

Checked that the outdoor air damper fully closes within a few minutes of shutting off appropriate air handler

Checked that the outdoor air damper opens (at least partially with no delay) when the air handler is turned on

If in heating mode, checked that the outdoor air damper goes to its minimum position (without completely closing) when the room

thermostat is set to 85°F

If in cooling mode, checked that the outdoor air damper goes to its minimum position (without completely closing) when the room thermostat is set to 60°F and mixed air thermostat is set to 45°F

If the outdoor air damper does not move, confirmed the following items:

• The damper actuator links to the damper shaft, and any linkage set screws or bolts are tight

• Moving parts are free of impediments (e.g., rust, corrosion)

• Electrical wire or pneumatic tubing connects to the damper actuator

• The outside air thermostat(s) is functioning properly (e.g., in the right location, calibrated correctly)

FREEZE STATS

NOTE: HVAC systems with water coils need protection from the cold. The freeze-stat may close the outdoor air damper and disconnect the supply air when tripped. The typical trip range is 35°F to 42°F.

Disconnected power to controls (for automatic reset only) to test continuity across terminals

Confirmed (if applicable) that depressing the manual reset button (usually red) trips the freeze stat (clicking sound indicates freeze stat was tripped)

Assessed the feasibility of replacing all manual reset freeze-stats with automatic reset freeze-stats

MIXED AIR THERMOSTATS

Ensured that the mixed air stat for heating mode is set no higher than 65°F

Ensured that the mixed air stat for cooling mode is set no lower than the room thermostat setting

ECONOMIZERS

Confirmed proper economizer settings based on design specifications or local practices

NOTE: The dry-bulb is typically set at 65°F or lower.

Checked that sensor on the economizer is shielded from direct sunlight

Ensured that dampers operate properly (for outside air, return air, exhaust/relief air, and recirculated air), per the design specifications

NOTE: Economizers use varying amounts of cool outdoor air to assist with the cooling load of the room or rooms. There are two types of economizers, dry-bulb and enthalpy. Dry-bulb economizers vary the amount of outdoor air based on outdoor temperature, and enthalpy economizers vary the amount of outdoor air based on outdoor temperature and humidity level.

FANS

Ensured that all fans (supply fans and associated return or relief fans) that move outside air indoors continuously operate during occupied hours (even when room thermostat is satisfied)

NOTE: If fan shuts off when the thermostat is satisfied, adjust control cycle as necessary to ensure sufficient outdoor air supply

AIR DISTRIBUTION

Ensured that supply and return air pathways in the existing ventilation system perform as required

Ensured that passive gravity relief ventilation systems and transfer grilles between rooms and corridors are functioning

NOTE: If ventilation system is closed or blocked to meet current fire codes, consult with a professional engineer for remedies.

Made sure every occupied space has supply of outdoor air (mechanical system or operable windows)

Ensured that supply and return vents are open and unblocked

NOTE: If outlets have been blocked intentionally to correct drafts or discomfort, investigate and correct the cause of the discomfort and reopen the vents

Modified the HVAC system to supply outside air to areas without an outdoor air supply

Modified existing HVAC systems to incorporate any room or zone layout and population changes

Moved all barriers (for example, room dividers, large free-standing blackboards or displays, bookshelves) that could block movement of air in the room, especially those blocking air vents

Ensured that unit ventilators are quiet enough to accommodate classroom activities

Ensured that classrooms are free of uncomfortable drafts produced by air from supply terminals

PRESSURIZATION IN BUILDINGS

NOTE: To prevent infiltration of outdoor pollutants, the ventilation system is designed to maintain positive pressurization in the building. Therefore, ensure that the system, including any exhaust fans, is operating on the “occupied” cycle when doing this activity

Ensured that air flows out of the building (using chemical smoke) through windows, doors, or other cracks and holes in exterior wall (for example, floor joints, pipe openings)

EXHAUST SYSTEMS
EXHAUST FAN OPERATION

Checked (using chemical smoke) that air flows into exhaust fan grille(s)

If fans are running but air is not flowing toward the exhaust intake, check for the following:

• Inoperable dampers

• Obstructed, leaky, or disconnected ductwork

• Undersized or improperly installed fan

• Broken fan belt

EXHAUST AIRFLOW

NOTE: Prevent migration of indoor contaminants from areas such as bathrooms, kitchens, and labs by keeping them under negative pressure (as compared to surrounding spaces)

Checked (using chemical smoke) that air is drawn into the room from adjacent spaces

Stand outside the room with the door slightly open while checking airflow high and low in the door opening

Ensured that air is flowing toward the exhaust intake

EXHAUST DUCTWORK

Checked that the exhaust ductwork downstream of the exhaust fan (which is under positive pressure) is sealed and in good condition

QUANTITY OF OUTDOOR AIR
OUTDOOR AIR MEASUREMENTS AND CALCULATIONS

Measured the quantity of outdoor air supplied to each ventilation unit

Calculated the number of occupants served by the ventilation unit under consideration

Divided outdoor air supply by the number of occupants to determine the existing quantity of outdoor air supply per person

ACCEPTABLE LEVELS OF OUTDOOR AIR QUANTITIES

Compared the existing outdoor air per person to the recommended levels

Corrected problems with ventilation units that supplied inadequate quantities of outdoor air to ensure that outdoor air quantities meet the recommended levels

COMPLETION

Recommendations

Inspector (Full Name and Signature)