Suspected Problem: An overheating problem in the Radiotherapy Planning Room that was part of a VAV air conditioning system with a dedicated VAV unit serving the Room. The client suspected they would need to replace their AC system.

Initial Observations: A preliminary inspection confirmed the room was, in fact, warm (25C) and conditions were stuffy.

Airthinx IAQ Data: After 2 days of monitoring the indoor air quality, the data indicated an odd pattern in the Temperature and Carbon Dioxide trends. The temperature was steady at 25 C +-0.5 C, regardless of time of day and the room use, and the CO2 was swinging wildly, peaking at 2000 ppm- confirming the feeling of stale air at the preliminary inspection.

Review of the Original System Design: With this new information, there was a review of the original system design which indicated that the VAV unit should be more than capable of providing enough fresh air to control the buildup of CO2.

Role of Facilities Management: A review of the new air quality data by the Facility Management department prompted a review of the Building Management System logs in the Room. A technician then checked the VAV box, finding a broken drive linkage on the VAV box. The technician fixed the VAV box.

Outcome: 10 mins after the VAV box was fixed, conditions in the room changed for the better, ruling out the suspected problem of an overload in the room as the source of air pollution. The room is now controlled at 22C, and CO2 remains steady at 600 ppm.

What the Client Said: The radiotherapists are very happy, and the hospital has not spent $50,000 on a new AC system to control the air quality conditions in the room.