Bright ideas boost energy efficiency

With the help of a sophisticated computer system, Tony Morizio can find out the temperature in every office in Toronto’s TD Centre towers.

Morizio is the controls supervisor for Cadillac Fairview, a corporation that owns and manages commercial real estate across North America. Part of Morizio’s job is to keep tabs on the energy use in the six office buildings that make up the TD Centre.

“The building automation system runs on computers like a network,” Morizio said. “You can tell what the temperature is in each area and by looking at these temperatures you can tell if the person sitting in that office is hot or cold.”

Complex systems such as the building’s automation system can help owners of large office buildings understand where energy is being used and how it can be used more efficiently.

In 2000, management at the downtown high rise launched a huge energy efficiency plan in order to trim the TD Centre’s energy appetite, signing on to the Better Buildings Partnership’s (BBP) Large Office Building Program, a public-private partnership that seeks to reduce Toronto’s carbon dioxide (CO2) emissions.

Sean Cosgrove is a research analyst for the BBP; he assesses how to enhance a building’s energy efficiency. He looks at the building’s air conditioning, boilers, lighting and water systems and its ventilation and suggests ways to improve them.

Cosgrove said many companies are concerned with the rising cost of energy, global warming and greenhouse gases. Taking part in environmental programs can improve a company’s reputation and bottom line.

Running hot and cold

A huge component of operating a building is managing heating and cooling, said Andrew Wilcox, assistant project manager at Enwave.

Hot or cold water is pumped around the building to either cool or heat the area. The pumps responsible sometimes need to circulate as far as the 54th floor of a building and are therefore massive.

“One major development in the last 10 years has been pumps which can vary the speed at which they run to meet demands in the building,” Wilcox said. “Previously, pumps would have run at a constant speed. They would pump the exact same amount of water all day long.”

By paying attention to on and off peak times, building owners ensure they can save a considerable amount of electricity, he said. For example, on a hot and sunny day the cooling load would be a lot higher and pumps would need to work at full capacity. At night there is a reduced need for cooling, therefore pumps can run slower, saving electricity.

Another large component of updating the TD Centre was making changes to the cooling systems. Wilcox said owners of the TD Centre were some of the first customers of Deep lake water cooling.

“We take water from the bottom of Lake Ontario and circulate it and use that to cool the buildings instead of electric chillers,” Wilcox said.

Deep lake water cooling

Although deep lake cooling is considered environmentally sustainable because it relies on a renewable resource, Wilcox said it does not guarantee a building will run more efficiently.

“Energy efficiency and Deep Lake Cooling are two different things,” Wilcox said. “Deep Lake Cooling is an alternative cooling service. So a building could purchase a chiller or they could sign a contract with Enwave for deep lake cooling,” he said.

The shift to energy efficiency changes the employees’ workspaces as well. “Certainly 10 years ago they wouldn’t have had the fluorescent fixtures that they do now,” Wilcox said.

“The amount of energy owners would have spent on lighting in a building would have been considerably higher 10 years ago.”

An employee today is likely using a computer with a flat-panel monitor, which emits almost no heat and uses a lot less power than older monitors. Wilcox said the use of Energy Star appliances such as dishwashers, kitchen ranges and microwave ovens in buildings has made a large impact on electricity usage.

“You say: ‘Oh it’s only one dishwasher,’ but if you see how many kitchens there are on each floor of the whole TD Centre, it would make a huge difference.”

Despite all the positive changes, Wilcox said electricity use isn’t actually declining. This is because of what is called plug power, the amount of power people use for things such as task lighting, computers and telephones.

“If you look at the TD Centre, the electricity uses in 1980 versus 1990 versus 2000, you’ll see that probably the electricity usage has stayed fairly steady,” he said.

“Demand for computers and technology has increased, while the demand from lights and heating and cooling has decreased.”

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Posted: Oct 13 2006 12:00 pm
Filed under: News