Nestled on the northern shore of Lake Superior, it gets cold in Thunder Bay, Ontario, Canada. The town typically has 203 days a year when the minimum temperature is at 0 °C or below. So it made sense when Dennis Wood, President of Cinevate in Thunder Bay, Ontario decided to take an existing 9,000 sq./ft. warehouse, gut it, and turn it into a net-zero energy building for his company.
As part of the project, the Tongdy CO2 Monitor with Relay was integrated into the system to control a heat recovery ventilator (HRV) that warms fresh air by transferring the BTUs from exhausted indoor air. CO2 meters help lower heating costs in many net zero installations.
"Despite investing in a complete "net zero" gut and retrofit of the building, I was feeling the need to add some needed intelligence to the ventilation system," Dennis said. Fortunately, he is a bit of a green energy geek, so after the remodeling job was completed, he set about to fine-tune the building with intelligent HVAC and lighting controls.
He started by installing motion-controlled thermostats and lighting - no more energy spent on empty rooms! Then he reached out to CO2Meter to purchase a wall-mounted Tongdy CO2 monitor/transmitter and a CO2Mini data logger.
Dennis used the CO2Mini to log CO2 levels on his laptop around the building to get a base-line reading of CO2 levels throughout the day. He was surprised that with heavy wind outdoors, the CO2 levels remained fairly constant. It was only on days with no wind and lots of staff in the building that the CO2 levels started to rise.
The next step was to install the Tongdy.
“We were trying to keep the building as simple as possible, so we deliberately avoided a dedicated building control,” Dennis said. “The smart thermostat can control an HRV using a standard set of dry contacts. But this only runs the HRV on a set schedule, rather than on demand.”
Using the built-in relay, the Tongdy was set to turn on the HRV at 900ppm, and turn it off at 700ppm. However, Dennis liked the fact that he could modify those values later as he dialed in the system. Rather than automatically cycling 20 minutes per hour Monday through Friday, with a CO2 controlled HRV, on some days the HRV did not run at all.
Dennis says his efforts have paid off. Already this winter he’s seen his energy bills go down even further.
“With the average temp -11C, last month my fuel bill was $156 for a 9,000 sq./ft. building,” he said. “For $200 dollars, the CO2 monitor has been a great investment. I think every building should have one.”
While his staff was originally indifferent to the CO2 meter, Dennis has noticed they are starting to pay attention to the green/yellow/red LEDs that indicate indoor air quality. In addition, they’ve figured out the manual override button on the front is useful for clearing odors out of the building.
“We're still dialing things in, but my team at Cinevate is happy, and comfortable,” he said.