Tips to help you be energy wise

• Maintain a reasonable setting in occupied areas (21°C in winter and 24°C in summer). Those areas will always be comfortable and the building won’t be overheated or over air-conditioned.
• Lower temperatures in unoccupied or rarely occupied areas like stairways and storage rooms.
• Gradually adjust temperature settings when occupants arrive to avoid starting all heating or air-conditioning equipment full on.
• Install a timer to set the desired temperature when the building is occupied (during unoccupied periods, we recommend setting the temperature at 18°C in winter and 26°C in summer).
• Use motion detectors, especially in small, well-defined areas, to adjust temperature settings automatically. The temperature will always be right, even when there’s no one there.
• Install an automatic temperature management system that operates in tandem with your access controls (e.g., hotel rooms linked to a reservation system, building zones accessed by employee access cards, etc.).
• Install electronic thermostats in every room for precise temperature controls.

• Install ceiling fans to avoid air stratification. In areas where the ceiling is higher (three metres or more), air temperatures can vary considerably.
• Minimize air infiltrations (especially around window frames and non-airtight walls).
• Install airtight, fast-opening and -closing garage doors and connect them automatically to the heating system.
• Prevent leaks by installing airtight dampers on ventilation system intakes.
• Insulate ventilation ducts and piping systems.

Save on heating and air-conditioning costs by keeping outside air outside!

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 your HVAC system supply air temperature to ensure that air is heated or cooled to the right temperature.

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.

• Use free cooling to cool your building with outside air.
• Hide content for Leveraging free cooling (depending on the temperature or enthalpy)

Keep closer tabs on your equipment and make any necessary corrections right away with help from a central control system.

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.

Get the heating capacity you need and greater precision with these devices.

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.

Recover up to 40% of exhaust air heat.

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 up to 50% of exhaust air heat.

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%.

Achieve thermal efficiencies of up to 60%.

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%.

Recover up to 70% of exhaust air heat.

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%.

Opt for the most efficient recovery system and achieve heat transfer levels of up to 85%.

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%.

Use the heat from one air-conditioned zone to heat another.

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.

Take advantage of the superior energy performance of aerothermal systems.

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.

Cut your heating and air-conditioning costs by using the energy stored in the ground.

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.

Get impressive results with an air-conditioning system that provides immediate energy exchanges.

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.

Air-condition your building with heat rejection equipment and save!

Cool your chilled-water circuit with equipment normally used to discharge building heat (like cooling towers) instead of a cooling system, and save!

Save by installing air-conditioning systems with superior energy efficiency ratios.

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.

Install a cooling system with a variable-speed compressor to adjust your electricity consumption according to your needs.

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.

Reduce your heating load by using sunlight to preheat air.

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.

Reduce your heating load by using sunlight to preheat air.

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.

Reduce your heating load by using sunlight to preheat water.

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.

Ensure your building envelope is well insulated to cut your heating and cooling costs.

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.

Energy management is the implementation of means of meeting energy needs as economically as possible. There are energy management systems that help large consumers to methodically monitor their various energy sources. They require work organization that allows systematic tracking of certain indicators, as well as the establishment of operating controls targeting optimum energy use.

Hydro-Québec’s Electricity Management Systems Program offers financial assistance for the implementation of this kind of energy management system.

A number of tools are available that you can use to launch a continuous improvement or energy management project.

Continuous improvement

There are several continuous improvement methods and tools, including the widely used Lean Six Sigma. In Québec, the Mouvement québécois de la qualité (MQQ) provides continuous improvement training and resources.

Continuous improvement resources of the Mouvement québécois de la qualité [in French only]

Reducing heat losses

CanmetENERGY, Canada’s leading research and technology organization in the field of clean energy, has developed a cutting-edge tool for optimizing heat recovery and reducing the use of thermal energy in facilities.

INTEGRATION software developed by CanmetENERGY

Operational data analysis

CanmetENERGY has also developed EXPLORE, a multivariate data analysis software program. It transforms existing data into valuable information and knowledge to help understand and improve process operation.

• Brochure on CanmetENERGY’s EXPLORE software program
• Hydro-Québec’s Electricity Management Systems Program offers assistance for continuous improvement.