A project to replace dehumidification and air handling equipment at the Nanaimo Aquatic Centre will be worth its weight in greenhouse gas emissions.
The City of Nanaimo's parks, recreation and culture has scheduled the replacement of two of the facility's main heat and air-conditioning and dehumidification systems. The project is scheduled for 2024-26 and has the potential to cut the aquatic centre’s greenhouse gas emissions by as much as 800 tonnes, representing 13 per cent of the City of Nanaimo’s annual GHG emissions from its facilities and operations.
"That's an astounding figure, 13 per cent of what the City of Nanaimo – its buildings, its staff, et cetera – produce in greenhouse gas emissions, with one change," said Nanaimo Mayor Leonard Krog at a special finance and audit committee meeting Nov. 2. "You show me any place in society you can reduce emissions 13 per cent with one project and I'll watch the pony fly."
The NAC uses natural gas to power water and air heating and air dehumidification to remove excess dampness and air contaminants from the building’s interior. When the aquatic centre's heating, filtration and control systems are upgraded, the unit at the core of the centre’s improved operating efficiency will be a large electric heat pump.
“We’re adding an air source heat pump,” said Jennifer McAskill, city manager of facility asset planning. “Think of your house and the heat pump that’s outside that provides heat. We’re using that same technology to pre-heat water and air that’s coming in.”
Water and air that needs to be brought to higher temperatures for showers and hot tubs, for example, will be heated by the facility’s natural gas-fired boiler system.
“We have to make sure that the water is stored at a safe temperature and that our patrons are experiencing appropriate service levels,” McAskill said.
An important part of the HVAC system is its ability to move excess humidity out of the building.
“At pools, like anywhere else, moisture in the air is going to affect any metals that are in there, any wood, you get steaming on the windows on the glass,” said Mike Bryson, deputy director of civic facilities. “Plus water droplets will also carry chemicals with them when the [pool] water off-gases and those chemicals are carried throughout the facility … So, we want to keep it at about 50 per cent relative humidity and we need the dehumidification to do that.”
Pre-heating water and air with an electric heat pump will drastically cut the amount of natural gas currently burned for the facility’s heating requirements.
The cost of the retrofit, which is currently in its design stages, is $5.3 million, but $3.8 million is being covered by a grant from the province.
The aquatic centre is also already using a new water purification system, which went into operation in November and is already cutting operational and energy costs. Bryson said the city observed "great results" piloting the technology in the leisure pool starting in 2023.
“So then we decided that we’d do the same thing in our main pool and our hot tub. We’ve got it all in place and we’re already seeing a change in the water.”
He said the new water filtration system will allow staff to reduce the amount of chemical additives by 30 to 50 per cent. A new water controller system monitoring water chemical levels to adjust alkalinity, hardness and other factors has turbidity sensors to signal pumps to turn up filtration flow if turbidity levels climb or slow pumps when turbidity levels fall, which will save substantially on electricity costs.
Combined with the new air-handling system and its control system that integrates with the building’s other water and environmental control systems, Bryson said the aquatic centre will be an efficient facility.
“Together it’s probably going to be one of the best-run facilities, as far as efficiency, air quality and water quality, in the province,” he said.
McAskill said for the money spent, pool patrons likely won’t see much of a difference inside the building, but they’ll feel the benefits of the retrofit.
“They should have a much better experience when they’re at the pool,” she said. “It won’t feel so muggy and humid in the pool rooms … The lifeguards will have a better place to work in. It’ll just be a more pleasant place to be.”
“And the water will be crystal, crystal clear,” Bryson added.
Planning for the retrofit will continue in 2025 and the work will be carried out in 2026.