Ventilation

Kitchen and Bathroom Fans

What is a dehumidistat? And what should I have it set to?

A dehumidistat is a device that reads the moisture of the air in your home. You can set dehumidistats to a humidity level that’s within the optimal humidity range for your health and comfort (between 40 and 65%). If the humidity levels rise above the level you’ve set, the dehumidistat will automatically turn on an exhaust device, such as a bathroom fan.
In general, the humidistat should be set according to the outdoor air temperature. When it’s colder outside, you’ll want to set your humidity level lower (but within the 40-60% range).

For more information, visit BC Hydro.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

How often should I run my bathroom fan? Should I get a timer?

To prevent moisture problems in your bathroom, you should turn on the bathroom fan when showering or taking a bath. The fan should be left running at least 30-54 minutes (or longer) afterwards to get rid of any excess moisture. Getting a timer for your bathroom fan can help ensure that your bathroom stays well-ventilated. You can set the timer to leave your bathroom fan running for a custom or manufacturer-set period of time and have it automatically shut off when the time is up.

For additional information, see “what is a dehumidistat?“.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

What are ENERGY STAR ventilation/exhaust fans?

Homes without adequate ventilation can have lingering odours and high humidity levels. ENERGY STAR® certified ventilation or exhaust fans including bathroom/utility room fans and range hoods, can provide the necessary ventilation to minimize or eliminate these problems resulting in a healthy indoor environment.

Ventilation fans have an electric motor that powers a fan. Moist air is drawn up through the fan into ductwork that exhausts to the outside.

A cross-section diagram of an ENERGY STAR ventilation fan.

VENTILATION FAN DIAGRAM LEGEND

  1. removable grille
  2. ventilation fan
  3. duct work vented outside
  4. roof vent cap
  5. timer/humidistat control switch
  6. interior ceiling

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

What are the benefits of ENERGY STAR ventilation/exhaust fans?

  • Saves energy and money: An ENERGY STAR® certified ventilation or exhaust fan uses 70% less energy, on average, than a standard model.
  • Superior health: Enhanced indoor air quality by exhausting excess moisture and indoor pollutants.
  • Quiet and reliable: High performance motors and improved blade designs results in quieter operation and longer life.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

What are the costs of ENERGY STAR ventilation fans?

The average cost for purchasing ENERGY STAR® certified ventilation fans can range from $100 to $400 dollars with installation costs dependent on numerous factors such as the presence of existing wiring and ducts. Be sure to get multiple quotes to compare costs, installation approach and warranties.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

How do I ensure that I get the right ventilation fans for my home?

Getting optimal performance from an ENERGY STAR® certified ventilation fan depends on more than just choosing the right equipment.

  • Consult with experts: Ask your energy advisor or contractor how this ENERGY STAR certified feature could transform your home.
  • Buy quality: Look for ENERGY STAR certified ventilation fans to ensure quality.
  • Use an accredited installer: Use an accredited TECA (Thermal Environmental Comfort Association of BC), ASTT (Association of Applied Technologists and Technicians), or HRAI (Heating, Refrigeration and Air Conditioning Institute of Canada) installer.
  • Ensure optimal performance: The quality of the installation can have an enormous effect on system performance and home comfort. Ask your contractor questions to ensure your system is properly sized and installed for optimal performance.
  • Maintain your equipment: Similar to servicing a vehicle, preventive maintenance is a good investment to minimize future problems. Keep the fan housing, blades, and ducting clean. Consult the owner’s manual for more details.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

Do I need a bathroom fan if my bathroom has a window?

The Canadian Mortgage and Housing Corporation (CMHC) recommends installing a bathroom fan that’s exhausted to the outside of your home because windows are not considered a reliable source of ventilation. Mechanical ventilation system should ideally balance the amount of air that’s drawn into your home and the amount that’s exhausted out.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

Do I need a range fan in my kitchen and how often should I use it?

Cooking and cleaning activities in your kitchen can generate excessive moisture that may lead to problems such as condensation and mould. The Canadian Mortgage and Housing Corporation (CMHC) recommends installing a kitchen range fan that’s exhausted to the outside of your home. You should turn on your kitchen range fan whenever you are cooking in your kitchen and leave it on at least a few minutes after you’re done.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

 

Heat Recovery Ventilators

Would I use more energy by running an HRV all the time?

HRVs and ERVs do require energy to run, but this energy is offset by the heat recovered from the exhaust air. Airtight homes equipped with heat recovery systems will have substantially lower energy costs per year than having ventilation without heat recovery. However if the house was significantly under-ventilated prior to the installation of the HRV/ERV the overall energy cost might go up due to the increased but now adequate ventilation rate.

To ensure that you home is well-ventilated and maintains good air quality, your HRV and ERV should run continuously. Many HRV fans can operate at low, medium, or high speeds depending on the ventilation requirements. A common control strategy is to have the HRV run continuously at low or medium speed, and switch to high speed when a higher ventilation rate is needed, such as when the bathroom is in use or during high occupancy periods.

For more information about HRVs, visit the Heat Recovery Ventilation Guide for Houses.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

Can I use my existing furnace ductwork for an HRV/ERV?

Yes, it is possible to connect an HRV or ERV to your existing furnace ductwork. If you are using your home’s current furnace ducting system, your furnace fan needs to stay on to ensure that fresh air gets distributed throughout your home. You can use the HRV or ERV control to turn on the furnace fan (this is known as interlocking).

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

What are heat recovery ventilators?

Mechanical ventilation and filtration with an ENERGY STAR® certified heat recovery ventilator (HRV) is an essential means of providing fresh air and maintaining healthy indoor air quality in a modern, well-sealed and insulated energy-efficient home. Older homes, and less efficient new homes, may have higher heating and cooling costs, poor indoor air quality, and higher humidity levels because they have insufficient ventilation systems and leak air and moisture through cracks and holes in the building envelope.

An HRV is a balanced ventilation system that uses a heat exchanger and a series of ducts and fans to blow stale air outside and bring filtered fresh air inside. It reduces heat loss by exchanging heat from outgoing stale air to warm up incoming fresh air. It also exhausts excess humidity to the outdoors.

A cross-section diagram of a heater recovery ventilator (HRV), with labels for: Fresh, outside air drawn into HRV; warm, stale indoor air drawn into HRV; cool, stale air expelled outside; heat from indoor air transferred to incoming fresh air stream; warm, clean, fresh air fills home.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

What are the benefits of HRVs?

  • A breath of fresh air: Stale air is replaced by a continuous supply of fresh air in your home.
  • Superior health: Enhanced indoor air quality by exhausting indoor pollutants and replacing it with filtered fresh air.
  • Improved comfort: More even temperatures through improved air circulation.
  • Energy savings: Recovers heat normally lost through conventional ventilation systems, reducing energy costs and your carbon footprint.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

What are the costs of HRVs?

The average cost for purchasing and installing an HRV ranges from $2000 to $5000. Factors that influence the cost include the size of your home, the model/brand and efficiency rating of the equipment and potentially the quality of the installation and system balancing. Be sure to get multiple quotes from contractors to compare costs, installation approach and warranties.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

How do I ensure that I get the right HRV for my home?

Getting optimal performance from a new ENERGY STAR® certified HRV depends on more than just choosing the right equipment.

  • Consult with experts: Ask your energy advisor how this ENERGY STAR certified feature could transform your home.
  • Buy quality: Look for an ENERGY STAR certified HRV to ensure a quality system.
  • Use an accredited installer: Contact an approved TECA (Thermal Environmental Comfort Association of BC) or HRAI (Heating, Refrigeration and Air Conditioning Institute of Canada) installer.
  • Ensure optimal performance: The quality of the installation can have an enormous effect on system performance and home comfort. Ask your installer questions to ensure your system is properly sized and balanced for optimal performance.
  • Maintain your equipment: Similar to servicing a vehicle, preventive maintenance is a good investment to minimize future problems. Arrange for annual servicing, keep the unit clean and inspect air filters every 1-3 months. Consult the owner’s manual for details.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

When should I get an HRV? Does my house need one?

Before upgrading your home’s ventilation system to an HRV, it’s important to understand the state of your home to assess whether a HRV will be a suitable upgrade.

There are three common scenarios with which a HRV upgrade would benefit a home:

  • Poor Indoor Air Quality
  • Excessive Moisture (condensation or mould issues)
  • Enclosure Upgrade Already Planned

If your home’s current ventilation system is inadequate, it’s important to investigate further to see if the issues can be resolved within the existing system. If they can’t be fixed, it may be time to upsize your existing ventilation system or invest in an ERV or HRV. In general, HRVs are recommended for airtight homes where a balanced system is required. For expert advice consider having an EnerGuide home evaluation and speak to a program-qualified energy advisor. The energy advisor can assess your home and see whether a HRV or ERV is right for your home.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.

What is the difference between an energy recovery ventilator (ERV) and heat recovery ventilator (HRV)? Which should I install?

Both HRVs and ERVs are mechanical ventilation devices that heat incoming outside air and provide good ventilation for you home. They use air being exhausted out of the home to preheat incoming outside air. ERVs differ from HRVs because they also help to regulate humidity levels in a home. ERVs transfer some of the moisture from more humid air flow to the drier flows of air. Airtight homes located in cold dry climates can sometime be dried out by HRVs. Most BC homes use HRVs for mechanical ventilation.

HRVs and ERVs are recommended for air tight homes that are normally closed up. If your home has issues with moisture and dryness, you should look into getting an ERV to maintain indoor relative humidity levels for your home. But if your home generates a significant amount of moisture (from high occupancy, pets, plants, or frequent cooking) then an HRV may be more appropriate for your home because an ERV may re-introduce too much moisture into your home.

For expert advice on which device is most suitable for your home, consider having an EnerGuide home evaluation and speak to a program-qualified energy advisor.

For more information about HRVs and ERVs, visit Natural Resources Canada and the Heat Recovery Ventilation Guide for Houses.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.