As a responsible manager and investor, you are just as concerned with your company’s financial performance as you are with its environmental impact.
By efficiently managing your energy consumption, you can both improve your bottom line and remain competitive. If you own a building or an industrial site, take a look at our lighting advice, which can also help you increase the market value of your building or site.
Did you know that up to 50% of your electricity bill goes to heating, and up to 15% more goes to air-conditioning?
Here are some ways to help you reduce your electricity consumption using energy-efficient technologies.
These measures qualify for financial assistance under the Buildings Program. Join the many customers already taking advantage of the program’s various benefits!
Ask a professional for help determining which measures are best suited for your building and objectives.
The following control and regulation measures can help you save electricity and money. Since the up-front investments are fairly small, you will be able to recoup your costs quickly.
Health issues can arise if the quantity of CO2 produced by building occupants exceeds a certain threshold—ideally, around 1,000 ppm. Install CO2 sensors in exhaust air ducts so that you can determine the amount of CO2 in the air and automatically inject the necessary quantity of outside air to bring it down to acceptable levels. Using CO2 sensors allows you to save on heating and cooling costs by limiting the volume of outside air that enters the building.
Adjust the temperature for each building zone according to the outside temperature or the maximum heating or cooling demand for the zone in question. This will enable you to adjust the air supply temperature as needed and avoid overheating or overcooling your indoor air.
Free cooling cools buildings by using outside air that is already at optimal enthalpy (temperature and humidity) levels, without the use of mechanical cooling systems. This technique is most useful in the spring and fall, when outdoor air conditions are best suited for it. In summer, use natural nighttime ventilation to evacuate the heat accumulated in the building during the day and reduce your electricity consumption.
Centralize all building operations using control software that lets you adjust many settings as needed, including operating schedules (for ventilation systems, lighting, pumps, etc.) and heating and cooling temperature settings. For instance, centralized control systems allow you to avoid air-conditioning and lighting unoccupied areas. Through remote access to centralized equipment, you can also monitor building operations more closely and take any necessary action on the spot.
Adjust your electric elements’ heating capacity to your specific needs by installing a thyristor-controlled regulator or triac controller. This prevents any risk of overheating, leading to considerable savings, and allows for a more precise temperature setting, which prevents heating element cycling (repeated starts and stops) and extends the element’s service life.
Did you know that a significant portion of the energy generated by a building can be recovered and reused? Here are some ways to recover 40% to 85% of the energy that would otherwise be lost.
Recover energy from exhaust air ducts by transferring the heat to a water loop. A pump circulates the fluid (a mixture of water and glycol) through the water loop and transfers the heat to the supply air duct. This solution can be a good choice for systems whose supply and exhaust ducts are not located near one another. It can achieve thermal efficiencies of up to 40%.
Recover exhaust duct energy by cooling the air mechanically before it is vented outside the building. The energy recovered by the cooling equipment is transferred into the building’s hot water loop. This solution may be a good choice for systems with supply and exhaust ducts not in proximity to one another, and can generate thermal efficiencies of up to 50%.
Recover the heat from your building’s exhaust air with a plate heat exchanger. These exchangers circulate fresh air and exhaust air through parallel, heat-conducting plates, which allows energy to be exchanged between them. For this system to work, the building’s fresh air and exhaust air ducts must be side by side. Such systems can deliver thermal efficiencies of up to 60%.
Extract the heat and moisture from your building’s exhaust air and use it to preheat or cool fresh air with a regenerative rotary heat exchanger (also known as a thermal wheel). Installed in an air-conditioning unit, this cylindrical heat recovery system is made of materials that absorb heat and rotates constantly. The building’s supply and exhaust air streams flow through it, exchanging energy between them. However, the supply and exhaust air ducts must be side by side. This type of heat recovery system provides thermal efficiencies of up to 70%.
Recover the heat from your central system’s exhaust air duct. With each cycle, the heat and moisture from the exhaust air is accumulated in one of the cassettes, while the other discharges the energy accumulated during the previous cycle into the fresh air duct. A system of mechanical dampers reverses the supply and exhaust air flows so that the cassettes can recharge and discharge simultaneously. Each cassette acts like a battery, constantly recharging and discharging. This is the most efficient type of heat recovery system, with a top thermal efficiency of 85%.
If you want to maximize your energy savings or upgrade your mechanical equipment at the end of its service life, the following measures can help. Although they require a larger initial outlay, they can lead to considerable savings.
Exchange heat energy between different zones using a distributed heat pump system. These air-water systems are particularly useful in areas that require both heating and cooling. They draw energy from a mixed water loop whose temperature is kept constant by means of a boiler or cooling system. The heat from one air-conditioned zone is released into the mixed water loop and used to heat another zone before the air is vented outdoors.
Heat and cool your building with aerothermal heat pumps and reap the benefits of their superior coefficient of performance (COP) and energy efficiency ratio. A system with a 2.5 COP uses just 1 kWh to transfer 2.5 kWh of heat. In winter, the heat pump compressor draws energy from the outside air and transfers it to the building. In summer, the compressor cools the building and releases the heat outdoors. As a rule, aerothermal heat pumps are central units. They are installed upstream of the building’s hot and cold water systems and supply energy to heating and air-conditioning systems like distributed heat pumps, fan-coil heaters and heating and cooling coils. Note that they are insufficient to heat buildings during very cold spells and require the use of auxiliary heating systems.
Geothermal systems harness the heat stored in the ground or reject heat into the ground, regardless of outdoor temperatures, by using a specially designed heat pump. There are several different types of geothermal systems. Central heat pumps are installed upstream of hot and cold water systems and transfer energy to heating and cooling equipment such as fan-coil systems and heating and cooling coils. There are also distributed heat pumps, which draw energy from geothermal water loops and release energy back into them. These air-water heat pumps are primarily installed in areas that have to be heated and cooled. This second type of system exchanges energy between different building zones, meaning that the heat extracted from an air-conditioned zone is transferred to the geothermal water loop and used to heat another zone before it is discharged into the ground.
Although this type of system is more expensive to install and does not suit all buildings, the savings are substantial and exceed those of aerothermal systems.
These state-of-the-art systems comprise a network of evaporators throughout the building. Controlled by individual thermostats, the evaporators are connected to refrigerant piping systems. The entire system is equipped with a variable-speed compressor connected to a single air- or water-cooled condenser. The system’s “brain” is a smart controller that distributes the refrigerant according to the heating or cooling needs of the zones serviced. Cooled zones immediately supply the heat required to heat other zones. This instantaneous exchange of energy makes these systems remarkably efficient.
Cool your chilled-water circuit with equipment normally used to discharge building heat (like cooling towers) instead of a cooling system, and save!
Use less energy to air-condition your building by installing a rooftop unit or cooling system with a higher energy efficiency ratio than your current system.
If you opt for a cooling system with a variable-speed compressor, you can adjust the speed (and your building’s power consumption) according to your cooling needs. This allows you to use the system at partial load and obtain a very good energy efficiency ratio.
The sun is an inexhaustible source of energy. Make the most of it by implementing the following measures.
A solar wall is a wall of metal or perforated glass that is installed on a south- or southwest-facing façade. It creates a space where outdoor air is preheated by the sun’s energy before being drawn into the building. Depending on the specific model and configuration, the fresh air is then heated by a device such as a heating coil or heat pump to reach the desired temperature in the ventilation system’s supply air duct. Perforated glass solar walls are more efficient than metal models.
Preheat your ventilation system’s fresh air with solar power. Installing a rooftop solar collector can reduce the amount of energy needed to heat the fresh air entering the building. Depending on the specific model and configuration, the fresh air is then heated by a device such as a heating coil or heat pump to reach the desired temperature in the ventilation system’s supply air duct.
Installed in full sun, this rooftop system comprises a system of metal pipes running beneath panels that absorb the sun’s heat. The water circulating in the pipes is preheated by the sunlight. Depending on the solar water heater’s characteristics, domestic hot water must then be heated by a standard water heater to reach the desired temperature.
If you’re planning on making major renovations to all or part of your building envelope, don’t forget about improving its efficiency too. You’ll save energy and money, and your building’s occupants will be more comfortable.
Help keep your building impervious to external conditions with a well-insulated envelope. Good-quality walls and ceilings with excellent thermal resistance can help reduce heat loss in the winter and keep hot air outside in the summer. Opt for double or triple glazing with argon for optimal thermal resistance, a low radiation absorption coefficient in the summer and superior airtightness. You’ll cut down on air leaks and reduce your heating and cooling costs substantially.