Success Story
Precision Equipment Improves Air Handling Unit
Correct Steam Traps & Pressure Power Pumps Keeps the OR AHU Running at Royal Columbian Hospital.
The Royal Columbian Hospital is the oldest hospital in the Canadian province of British Columbia and one of the busiest in the Fraser Health Authority. Royal Columbian Hospital is a major tertiary care facility known for trauma care, neurosurgery, and open-heart surgery.
The operating rooms require 100% make up air and a project to upgrade the air system with a new energy efficient one was undertaken with a new rooftop AHU installed. Problems arose on the shoulder seasons with the freeze stats shutting down the air handler under certain outside air conditions. A call was made to Andrew Reynolds to investigate and provide a solution. Upon investigation two major issues were discovered. The steam coil selection was correctly chosen to be freeze proof tube with a tube design, however the 1 ¼” tubes as per the performance data were actually constructed as 5/8” tubes. Secondly, the condensate would backup in the tubes due to lack of vacuum breakers, undersized steam traps and back pressure on the condensate system.
The solution was to replace the freeze proof tube with the correct size, install vacuum breakers, correctly size the steam traps and have a steam powered condensate pump return condensate back to the boiler room.
The results are the AHU now runs under all load conditions and the freeze stats not locking out the system. Chris Nicol from Fraser Health reports the system is performing consistently and reliably.
Did You Know?
Consider Installing a Condensing Economizer
Boilers equipped with condensing economizers can have an overall efficiency that exceeds 90%. A condensing economizer can increase overall heat recovery and steam system efficiency by up to 10% by reducing the flue gas temperature below its dew point and improves the effectiveness of waste heat recovery and fall under 2 categories. An indirect contact condensing economizer removes heat from hot flue gases by passing them through one or more shell-and-tube or tubular heat exchangers. A direct contact condensing economizer consists of a vapor-conditioning chamber followed by a countercurrent spray chamber. In the spray chamber, the cool liquid come into direct contact with the hot flue gas, providing a non-fouling heat transfer surface
