Apartment OR IN-UNIT Ventilation

Exhaust (SOURCE CONTROL VENTILATION)

BATHROOM EXHAUST THROUGH (SHARED ERV OR HRV):

  • Every bathroom must include an exhaust fan that runs continuously. This approach employs continuous exhaust flow to achieve source control of excess humidity and odors. Ideally supply and exhaust systems are balanced and utilize recovery in the form of an ERV or an HRV.

    At a minimum, the bath exhaust fans should:

    • Run continuously in each bathroom at a 25 CFM for background exhaust.

    • Bath Exhaust should never terminate into the attic.

    • Seal the shaft all ductwork or all vertical ductwork to 5cfm at 50 Pascals per floor or less

    • Install Constant Airflow Regulators (CARs) for each exhaust intake grille to control exhaust flow rate.

    • Coordinate with Background Ventilation design to create a balance.

KITCHEN EXHAUST (SHARED ERV OR HRV):

Kitchen exhaust is either intermittent through a capture hood over the cook-top or continuous through a general area exhaust located in the cooking area. 

  • Continuous General Kitchen Exhaust: preferred method to integrate with Background Ventilation ERV. Every kitchen must include exhaust with a through wall/ceiling grill that:

    • Runs continuously at a 35 CFM for background exhaust.

    • Ensure exhaust grill is a minimum 6’ distance from cook-top.

    • Ensure washable filter at the exhaust grill.

    • Review design with ERV manufacturer.

    • Install recirculation capture hood over cooking range.

    • Install Constant Airflow Regulators (CARs) for each exhaust intake grille to control exhaust flow rate.

    • Coordinate with Background Ventilation design.

  • Range Hood: If continuous general kitchen exhaust through ERV is not possible, every kitchen must exhaust to exterior by using one of the following systems:

    • Range hood with integral fan exhausted directly to exterior; or

    • Range hood connected to a shared exhaust riser served by a rooftop fan exhausted to exterior.

  •  The following applies to all range hood installations:

    • Sone level should be maximum 7. 

    • Kitchen exhaust fan ductwork should never terminate into attic space.

    • Kitchen exhaust fan should include back draft damper.

    • CFM rating should be minimum 150.

    • Assist capacity required for buildings 3 stories and above. Install direct drive exhaust riser fan with variable speed barometric control to maintain duct pressure after existing ductwork has been sealed.

    • Range hood should be deep enough that Range Queen, when installed, is not visible. Range Queen Product information is found within the Rangehood BOD section. See link below.

Sample products are located in the RANGEHOOD page of the APPLIANCES section:

SUPPLY (FRESH AIR):

BALANCED VENTILATION SYSTEM WITH RECOVERY PREFERRED SYSTEM IN NEW CONSTRUCTION AND REHABS:

Balanced ventilation can be described as exhausting stale/humid air and suppling fresh air at equal rates (cfm). The best design is general exhaust from the kitchen and bathroom and supply to the living room and bedrooms. Ideally provide balanced ventilation with Energy Recovery Ventilation (ERV) units. Heat Recovery Ventilation (HRV) may be permitted in dry climates, but requires prior approval from the Design & Building Performance Dept. Using a recovery system saves energy by capturing heat and humidity in the exhaust air. The captured heat is used to temper the supply air. There are a few strategies for installing a balanced ventilation system with recovery, see below for descriptions.

SEMI-CENTRALIZED ERV (OR HRV)

This is a horizontal ventilation approach that eliminates the need for vertical duct risers, associated fire dampers.  It can be used in midrise and high-rise buildings with a double loaded corridor.

  • ERVs located on each floor. May require/be advantageous to have more than one ERV per floor.

    • Horizontal supply and return air ducts from units to ERV(s).

    • Supply air is ducted to each living room and each bedroom.

    • Supply air duct is insulated for condensation control.

    • Exhaust air from bathrooms and general area kitchen exhaust.

      • Rangehood kitchen exhaust risers should NOT be connected to the ERV/ HRV due to grease buildup.

    • Insulated horizontal outdoor air and exhaust air duct from ERV(s) through exterior wall.

      • Minimize unconditioned air duct length, locate close to an exterior wall.

    • Install Constant Airflow Regulators (CARs) for each supply and exhaust location.

    • Locate ERVs in serviceable locations:

      • Ceiling mounted ERVs require ceiling access for filter changes, but do not require mechanical rooms. Can be installed in the corridors.

      • Floor mounted ERVs require mechanical rooms.

      • Provide post ERV refrigerant coil or hydronic coil

      • Provide enthalpy control (control humidity/moisture) of supply air. Every ERV requires humidity (moisture) control of post-ERV air. 

      • Control Discharge Air Temperature (DAT) (Supply air)(variable) for comfort based on season. E.G. 55F DAT in summer and 70F DAT in winter.

    • ERV must have economizer. Controls must be capable of incorporating economizer when OA is beneficial.

    • Architectural coordination requirements:

      • Provide adequate floor-to-floor height for coordinating ducts with other services.

      • Accommodate supply and exhaust penetrations through enclosure.

SEMI-CENTRALIZED ERV OPTIONS:

  • Examples of successful ERVs – Ventacity Ceiling Mount Ventilators:

    • VS250CMe         60-270 CFM

    • VS400Cme          120-400 CFM

    • VS900Cme          200-900 CFM

    • VS1200Cme       300-1200 CFM

https://www.ventacity.com/products/ventilation-family/

CENTRAL ERV (OR HRV)

A more traditional approach which locates the ERV in a central location with vertical and horizontal duct distribution. This approach allows for minimizing the number of penetrations through the exterior enclosure but will require more penetrations through assemblies within the building.

  • ERV(s) are located:

    • Internally, such as in the attic or mechanical room.

      • Preferred for ventilation system performance and ERV durability.

      • Provide adequate access for future replacement of ERV. I.E., does not require cutting open a roof to replace ERV.

    • Rooftop.

      • Minimize rooftop ductwork.

  • Supply air is ducted to each living room and each bedroom.

  • Supply air duct is insulated for condensation control.

  • Exhaust air from bathrooms and general area kitchen exhaust.

    • Rangehood kitchen exhaust risers should NOT be connected to the ERV/ HRV due to grease buildup.

  • If ERV(s) is internal, insulate horizontal outdoor air and exhaust air duct from ERV(s).

  • Horizontal and/or vertical supply and return air ducts from units to ERV(s).

  • Install Constant Airflow Regulators (CARs) for each supply and exhaust location.

  • ERV should control supply air:

    • Provide enthalpy control (control humidity/moisture) of Discharge Air (supply air). Every ERV requires humidity (moisture) control of post-ERV air.

    • Control Discharge Air Temperature (DAT) (Supply air)(variable) for comfort based on season. E.G. 55F DAT in summer and 70F DAT in winter.

    • ERV to temper the air with:

      • Provide post ERV refrigerant coil or hydronic coil.

      • Integral heat pump for large ERV.

      • ERV must have economizer. Controls must be capable of incorporating economizer when OA is beneficial.

CENTRALIZED ERV OPTIONS:

  • Examples of successful ERVs – Ventacity Ceiling Mount Ventilators:

    • VS1000Rte         75-1000 CFM

    • VS3000Rte 750-3000 CFM

INDIVIDUAL APARTMENT ERV (OR HRV)

Individual apartment ERVs (or HRVs) are suitable for single dwellings and townhomes where a larger ducted system is not practical. It offers the advantage of apartment-level control, off-the-shelf products and minimized risk of cross-contamination between apartments. 

  • ERV is located within the unit:

    • Insulated horizontal outdoor air and exhaust air duct from ERV(s) through exterior wall.

      • Minimize unconditioned air duct length, locate close to an exterior wall.

  • ERV supply:

    • Supply air is ducted to each living room and each bedroom.

    • Alternatively supply air is ducted to the return of the Fan Coil Unit (FCU); FCU is used for post ERV tempering. This requires further design consideration:

      • FCU diffusers must not cause drafts, comfort issues.

      • Control strategy to ensure air is circulated to occupied spaces when FCU thermal setpoint is met.

    • Supply air duct is insulated for condensation control.

  • Exhaust air from bathrooms and general area kitchen exhaust.

    • Rangehood kitchen exhaust risers should NOT be connected to the ERV/ HRV due to grease buildup.

  • Requires periodic in-unit equipment maintenance.

INDIVIDUAL ERV OPTION: