Engineer Building Facilities flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Chiller kW per ton

Efficiency metric equal to 3.517 divided by COP. A chiller drawing 0.6 kW per ton runs at a COP of about 5.9, and a lower kW per ton means better efficiency.

Fan affinity laws

At constant air density, airflow varies with fan speed, static pressure with speed squared, and brake horsepower with speed cubed. Halving speed cuts power to one-eighth.

Cooling tower approach

The difference between leaving condenser-water temperature and entering wet-bulb temperature. A design approach of 3–7°F shows how closely the tower reaches the ambient wet bulb.

Economizer changeover setpoint

The outdoor-air condition at which the air-side economizer enables or disables free cooling, commonly 55–65°F dry bulb or an enthalpy comparison against return air.

Fixture trap seal

The water depth held in a plumbing trap, normally 2–4 inches, which blocks sewer gas. Evaporation in unused fixtures requires trap primers or trap guards.

Power factor

The ratio of real power in kW to apparent power in kVA. Utilities may bill a penalty below roughly 0.90, and capacitor banks or synchronous motors correct a low value.

Elevator Phase I recall

Automatic or keyed recall of elevator cars to a designated floor on smoke-detector alarm, with normal power operation disabled so firefighters can use the car under Phase II.

Span of control

The number of direct reports one supervisor manages. Three to seven is the usual range; wider spans demand standardized work, fewer exceptions, and experienced staff.

FTE calculation

Annual labor hours required divided by the productive hours one full-time employee delivers, generally 1,750–1,850 after vacation, holidays, sick leave, and training are removed.

Mean time to repair

Total downtime divided by the number of repair events in a period. MTTR measures how quickly the team restores equipment and feeds availability calculations.

Availability metric

Mean time between failures divided by the sum of MTBF and MTTR, expressed as a percentage. Ninety-nine percent availability allows roughly 87.6 hours of unplanned downtime yearly.

Progressive discipline

A documented escalation of corrective action, typically verbal warning, written warning, suspension, then termination, applied consistently so employees receive clear notice and a chance to improve.

Work order backlog

Open work orders divided by the average weekly completion rate, expressed in weeks. A backlog beyond four to six weeks signals a staffing shortfall or a scheduling bottleneck.

NYC high-rise definition

Under the NYC Building Code, a building with an occupied floor located more than 75 feet above the lowest level of fire department vehicle access.

FISP facade inspection

NYC Facade Inspection Safety Program: exterior walls and appurtenances of buildings more than six stories are inspected every five years and filed as Safe, SWARMP, or Unsafe.

Local Law 97

NYC carbon-emissions caps for buildings over 25,000 square feet, with limits for 2024–2029 and stricter 2030–2034 limits; annual reports are filed and overages incur per-ton penalties.

Fire Safety Director

An FDNY-certified coordinator required in designated high-rise office, hotel, and other occupancies, responsible for the fire safety plan, staff training, drills, and the lobby command station.

NFPA 25 monthly check

Sprinkler system gauge readings and valve positions are inspected monthly; annual work includes main drain flow tests, alarm tests, and valve operation by a qualified contractor.

ACP-5 filing

A NYC DEP asbestos inspection form certifying whether asbestos-containing material is present before renovation or demolition; a copy must be on site before suspect materials are disturbed.

Generator load test

NFPA 110 requires weekly generator exercise plus periodic load testing; Level 1 emergency systems typically get an annual test at 30 percent or more of nameplate for 30 minutes.

Three-way match

A control that compares the purchase order, receiving report, and vendor invoice for quantity and price agreement before accounts payable releases payment to the supplier.

Retainage

A percentage, usually 5–10 percent, withheld from each progress payment until substantial completion and punch-list closeout, protecting the owner against incomplete or defective work.

Simple payback

Capital cost divided by annual net savings, expressed in years. It is easy to communicate but ignores the time value of money and any savings after payback.

Deferred maintenance ratio

The deferred maintenance backlog divided by the current replacement value of the asset base. Industry benchmarks flag ratios above roughly 2–5 percent as a growing capital risk.

IDIQ contract

Indefinite delivery, indefinite quantity: a pre-priced umbrella contract with one or more vendors for recurring or unpredictable work, ordered by task or delivery orders over a stated term.

Liquidated damages

A pre-agreed per-day sum a contractor owes for late completion. Courts enforce it only when it reasonably forecasts the owner's actual loss rather than acting as a penalty.

Sensible heat equation

Q in Btu per hour equals 1.08 times airflow in CFM times the dry-bulb temperature difference in degrees Fahrenheit across the coil or space.

Water heating equation

Q in Btu per hour equals 500 times flow in gallons per minute times the temperature difference in Fahrenheit, where 500 reflects water density of 8.33 pounds per gallon.

Refrigeration ton

A cooling rate equal to 12,000 Btu per hour, 200 Btu per minute, or 3.517 kilowatts, originally defined as heat absorbed melting one ton of ice daily.

Pump brake horsepower

Brake horsepower equals gallons per minute times total head in feet times specific gravity, divided by 3,960 times the pump efficiency expressed as a decimal.

Three-phase power formula

Kilowatts equal the square root of three, multiplied by volts, amps, and power factor, then divided by 1,000 for a balanced three-phase load.

Lumen method

Average illuminance in footcandles equals lumens per lamp times lamp count times coefficient of utilization times light loss factor, divided by floor area in square feet.