CRECI Building Operations and Maintenance 3 — Questions and Answers
Question 1: A property manager notices the building's domestic hot water temperature has dropped to 105°F. Beyond tenant discomfort, what is the primary safety concern?
- Legionella bacteria proliferation in the hot water system (Correct answer)
- Scalding risk increases significantly at lower temperatures
- Reduced water pressure throughout the building
- Premature corrosion of the water heater tank
Correct answer: Legionella bacteria proliferation in the hot water system
Legionella pneumophila thrives at 77–108°F; ASHRAE 188 recommends maintaining stored hot water at a minimum of 140°F to prevent Legionella growth.
Question 2: Under the Americans with Disabilities Act (ADA), when a commercial building undergoes a path-of-travel alteration, what percentage of the total alteration cost must an owner spend on accessibility improvements before the path-of-travel requirement is considered disproportionate?
- 20% (Correct answer)
- 10%
- 30%
- 50%
Correct answer: 20%
ADA regulations require accessibility improvements to the path of travel up to 20% of the cost of the primary alteration before the disproportionate-cost exception applies.
Question 3: A building automation system (BAS) is showing a 'high duct static pressure' alarm on an air handling unit. What is the most likely root cause?
- A clogged air filter or closed VAV boxes reducing airflow (Correct answer)
- A faulty static pressure sensor giving false readings
- Excessive outdoor air economizer operation
- Chilled water valve stuck in the open position
Correct answer: A clogged air filter or closed VAV boxes reducing airflow
High duct static pressure typically results from restricted airflow caused by a dirty filter or VAV terminal units that have closed down, forcing the fan to build more pressure.
Question 4: What is the primary purpose of a Commissioning Authority (CxA) during a major building renovation?
- To verify that installed building systems meet the owner's project requirements and design intent (Correct answer)
- To manage subcontractor scheduling and construction sequencing
- To obtain building permits and coordinate with the authority having jurisdiction
- To negotiate equipment warranty terms with manufacturers
Correct answer: To verify that installed building systems meet the owner's project requirements and design intent
The CxA independently verifies that mechanical, electrical, and plumbing systems are installed, tested, and operating per the Owner's Project Requirements (OPR) and Basis of Design (BOD).
Question 5: A parking garage's CO monitoring system activates the ventilation fans continuously even at 3 AM when the garage is empty. What is the most cost-effective corrective action?
- Calibrate or replace the CO sensors, as false readings from sensor drift are the likely cause (Correct answer)
- Override the system manually each night to prevent unnecessary fan operation
- Install a time clock to disable the CO system during off-hours
- Upgrade to a larger, more powerful exhaust fan system
Correct answer: Calibrate or replace the CO sensors, as false readings from sensor drift are the likely cause
CO sensor drift is a common cause of false alarms; recalibration or sensor replacement restores accurate monitoring and eliminates unnecessary energy waste.
Question 6: Which type of roof membrane system requires an annual inspection that specifically checks for 'fishmouths' and lap seam integrity?
- Single-ply thermoplastic (TPO or PVC) membrane (Correct answer)
- Built-up roofing (BUR) with gravel ballast
- Metal standing seam panel system
- Spray polyurethane foam (SPF) system
Correct answer: Single-ply thermoplastic (TPO or PVC) membrane
TPO and PVC single-ply membranes are heat-welded at seams; fishmouths (unsealed seam edges) are a primary failure point that annual inspection must identify.
Question 7: A commercial property's emergency generator fails to start during a utility power outage. The weekly exercise log shows the generator has been running unloaded every week. What maintenance practice most likely contributed to this failure?
- Wet stacking from insufficient load during exercise, causing carbon buildup in the engine (Correct answer)
- Overcharging of the starting battery during frequent short exercise cycles
- Excessive coolant changes depleting corrosion inhibitor additives
- Fuel injector wear from too-frequent operation
Correct answer: Wet stacking from insufficient load during exercise, causing carbon buildup in the engine
Running a diesel generator under little or no load causes 'wet stacking'—unburned fuel and carbon accumulate in the exhaust system and cylinders, leading to reliability problems.
CRECI Building Operations and Maintenance 3
A property manager notices the building's domestic hot water temperature has dropped to 105°F.
Beyond tenant discomfort, what is the primary safety concern?