School District 71 is looking at bringing in direct digital control (DDC) systems at couple more schools to improve energy efficiency.
Director of operations Ian Heselgrave outlined the work for Brooklyn Elementary and Queneesh Elementary at a board meeting earlier this year.
“We’ve lowered the CO2 levels in all our schools,” he told the board. “It reduces greenhouse gas consumption.”
The board approved the DDC upgrades, within funding first coming from the federal COVID-19 fund and the remainder from capital reserves to a maximum of $425,000.
Along with improving the heating and cooling, the work will also help facilitate better airflow in the school buildings. According to a staff report, DDC systems vary in complexity depending on the building. A system may control only a building’s HVAC (heating, ventilation and air conditioning) system, or it can automate an entire building by also controlling other mechanical and electrical systems. DDCs can increase a building’s comfort levels and decrease energy consumption at the same time, potentially paying for themselves relatively quickly.
“Their purpose is to ensure that the school heats and cools efficiently and effectively,” Heselgrave said.
The report notes that replacing the DDC system at Huband Park Elementary last year resulted in a reduction of 204 gigajoules of natural gas and a 10.5-tonne reduction in annual greenhouse gas emissions.
Another consideration this past year prompting the need to finish the DDC upgrades is COVID-19, which has brought further attention to ventilation in school buildings. Through the summer and fall, the school district operations department worked to implement a number of recommendations to improve ventilation, such as flushing out air inside buildings prior to occupancy each weekday, increasing the minimum outside air damper position of all existing air-handling systems to bring in more fresh air from outside and running variable speed air-handling systems at 100 per cent fanspeed for a large space such as gymnasium while it is occupied.
The department has been updating DDC systems at various schools around the district for the last seven or eight years, Heselgrave said, and was finishing up at Aspen Park at the time of the meeting.
“There’s been a real push in the last year to accelerate this work,” he said.
Board chair Sheila McDonnell was happy to see the last of the schools being completed, adding the HVAC systems have been an issue for as long as she has been a school trustee.
“This is a real achievement to have completed the whole project,” she said.