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Balanced HRV/ERV

Many homes are missing whole-house fresh air systems that ensure adequate dilution of moisture, dust, pollen, and particulates inside the home. These contaminants can trigger asthma and allergy attacks as well as other health problems. Balanced heat recovery ventilation (HRV) and enthalpy recovery ventilation (ERV) provide an equal amount of supply and exhaust air adequate for effective dilution of contaminants. HRV’s include a heat exchanger to capture heat from exhaust air in the winter and supply air in summer for added efficiency. ERV’s also help remove unwanted outdoor moisture in summer and retain desired indoor moisture in winter for added comfort. However, critical installation best practices need to be followed to ensure a successful project. Use this checklist to get the significant health and enhanced comfort benefits possible from a quality installed balanced HRV/ERV fresh air system.

Properly installed ERV/HRV

Heat Recovery Ventilator (HRV)

Publication Date

November, 2009

Organization(s)

Cold Climate Housing Research Center,

CCHRC

Video describing the Cold Climate Housing Research Center heat recovery ventilator system.

Jorge and Paul's Adventure with HRV

Publication Date

March, 2012

Author(s)

Simmons

Organization(s)

Cold Climate Housing Research Center,

CCHRC

Video describing the importance of a heat recovery ventilator system and potential moisture problems that can be prevented through its use in cold climates like Alaska.

An HRV or ERV provides balanced ventilation

Publication Date

Thu, 01/10/2013 - 12:00

Karuna Passive House HRV Supply Register

Publication Date

May, 2013

Video discussing the heat recovery ventilation (HRV) system in a passive house.

These ERV/HRV configurations are NOT recommended because outdoor air can be sucked back into the ERV/HRV before being distributed to the living space

Reference

Measure Guideline: Selecting Ventilation Systems for Existing Homes

Author(s)

Aldrich Robb

Organization(s)

Consortium for Advanced Residential Buildings,

CARB,

Steven Winter Associates,

SWA,

U.S. Department of Energy,

DOE

This document addresses adding—or improving—mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes either directly or by dilution. This report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards.

Publication Date

Sat, 02/01/2014 - 12:00

Wrong - The holes around the HRV ducting should be air sealed.

Publication Date

Wed, 07/07/2021 - 12:00

Heat Recovery Ventilator (HRV) or Energy (Enthalpy) Recovery Ventilator (ERV)

Right - Diameter measurement of small through-the-wall HRV unit; 4 of 14.

Publication Date

Wed, 08/26/2020 - 12:00

This HRV, installed in a conditioned attic, provides balanced ventilation to the whole home

Reference

Measure Guideline: Selecting Ventilation Systems for Existing Homes

Author(s)

Aldrich Robb

Organization(s)

Consortium for Advanced Residential Buildings,

CARB,

Steven Winter Associates,

SWA,

U.S. Department of Energy,

DOE

This document addresses adding—or improving—mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes either directly or by dilution. This report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards.

Reference

Measure Guideline: Selecting Ventilation Systems for Existing Homes

Author(s)

Aldrich Robb

Organization(s)

Consortium for Advanced Residential Buildings,

CARB,

Steven Winter Associates,

SWA,

U.S. Department of Energy,

DOE

This document addresses adding—or improving—mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes either directly or by dilution. This report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards.

Publication Date

Sat, 02/01/2014 - 12:00

Right – This HRV is ducted separately from the home’s ductless heat pumps to provide filtered fresh air to sleeping and living areas and to exhaust stale air from the bathrooms and laundry.

Publication Date

Thu, 09/30/2021 - 12:00

Karuna Passive House Ventilation System

Publication Date

May, 2013

Video discussing the heat recovery ventilation (HRV) system in a passive house.

Air Sealing Colorado Homes – 10.634

Author(s)

Weiner C.

Organization(s)

Colorado State University,

U.S. Department of Agriculture,

USDA

Publication Date

July, 2019

Fact sheet describing air-sealing concerns and remedies, including HRV/ERV installation, caulking, spray foam, and weatherstrip installation.

Ventilation Air Inlet Locations

Guide describing how to install ventilation air inlets in open locations at a safe distance from potential air contamination sources.

Whole House Ventilation Strategies for Existing Homes

Guide describing how to select and install whole-house ventilation systems for existing homes.

Outdoor Air Intake Damper Controlled

No outdoor air intakes connected to return side of the HVAC system, unless controls are installed to operate intermittently & automatically based on a timer and to restrict intake when not in use (e.g., motorized damper)

Obvious Ventilation Controls

Guide describing how to install obvious ventilation controls.

Whole-House Ventilation Strategies for New Homes

This guide describes how to install a whole-building ventilation system to provide adequate dilution of indoor air contaminants.

Whole-House Mechanical Ventilation System meets ASHRAE 62.2

This information guide describes the minimum ventilation requirements for a DOE Zero Energy Ready certified home.

Continuously Operating Ventilation and Exhaust Fans

Guide describing how to install continuously operating exhaust fans.

Sealed and Insulated Metal Ducts

Guide describing how to air seal and insulate metal ducts.

Heat Recovery Ventilation in Colder Climates - Code Compliance Brief

Publication Date

October, 2016

The intent of this brief is to provide code-related information about heat recovery ventilation to help ensure that what is proposed regarding the heat recovery ventilator ‘product’ itself as well as ventilation measures can be verified as being in compliance with the code. Providing consistent information to document compliance with codes and standards to all relevant parties responsible for verifying with those codes and standards (e.g., code officials, builders, contractors, designers, etc.) is expected to result in increased compliance and more timely, less challenging and more uniform plan review and field inspections.