FreshVent exterior fresh-air intake for ERV, HRV and make-up-air ventilation systems

What Is a Fresh-Air Intake Vent? ERV, HRV & Make-Up Air Guide

What Is a Fresh-Air Intake Vent?

A fresh-air intake vent is an exterior opening designed to bring outdoor air into a home or building as part of a mechanical ventilation system.

Unlike a bathroom, kitchen, or dryer exhaust vent—which removes air from the building—a fresh-air intake supplies outdoor air to equipment such as an ERV, HRV, dedicated ventilation system, or make-up-air system.

The exterior termination matters because incoming air needs a clear airflow path while also being protected from rain, insects, debris, and other outdoor conditions.

InOvate’s FreshVent is designed specifically as an exterior fresh-air intake port for ERV, HRV, make-up-air, and balanced ventilation systems. It is available in 4-inch and 6-inch configurations and uses precision-formed 22-gauge Galvalume steel with a powder-coated exterior finish.

Fresh-Air Intake vs. Exhaust Vent: What Is the Difference?

The easiest distinction is the direction of airflow.

An exhaust vent moves indoor air out of the building. Examples include bathroom exhaust, kitchen exhaust, and dryer exhaust.

A fresh-air intake moves outdoor air into the building.

That difference affects the way the exterior termination should be designed. Fresh-air and make-up-air intakes need weather protection and screening to help prevent insects and debris from entering the system. InOvate specifically notes that, unlike dryer exhaust terminations, fresh-air intakes can and should use screening.

This is why an exterior vent cap should not automatically be treated as interchangeable between intake and exhaust applications.

What Is the Difference Between an ERV and an HRV?

Both an ERV (Energy Recovery Ventilator) and an HRV (Heat Recovery Ventilator) are designed to bring fresh outdoor air into a building while exhausting stale indoor air.

The main difference is how they handle heat and moisture.

HRV — Heat Recovery Ventilator

An HRV transfers heat between the incoming and outgoing air streams.

During cold weather, heat from the outgoing indoor air can be transferred to the colder incoming outdoor air. During warmer conditions, the process can work in the opposite direction to reduce some of the temperature load on the HVAC system.

HRVs are commonly used where heat recovery is important and moisture transfer between the two air streams is not desired.

ERV — Energy Recovery Ventilator

An ERV transfers heat and some moisture between the incoming and outgoing air streams.

That moisture-transfer capability can be useful in humid climates because the ERV can help reduce some of the moisture entering with outdoor ventilation air. In colder conditions, it can also help retain some indoor humidity that might otherwise be exhausted.

The best choice between an ERV and HRV depends on factors such as:

  • Climate

  • Building type

  • Indoor humidity requirements

  • HVAC-system design

  • Occupancy

  • Local ventilation requirements

Both Systems Need Exterior Intake and Exhaust Terminations

Regardless of whether the system uses an ERV or HRV, it generally needs two separate exterior air paths:

Fresh-air intake → brings outdoor air into the system

Exhaust termination → discharges stale indoor air outdoors

These openings should not be positioned so close together that exhausted air can be drawn directly back into the fresh-air intake.

The exterior intake should also be protected from rain, insects, leaves, and debris while maintaining adequate airflow for the ventilation equipment.

A purpose-built intake termination such as FreshVent is designed specifically for this fresh-air side of the system.

Why Does Fresh-Air Intake Location Matter?

The location of a fresh-air intake can affect both indoor air quality and system performance.

Because the vent is intentionally drawing outdoor air into the building, it should be positioned away from sources that could introduce contaminated or poor-quality air.

Potential concerns include:

  • Dryer exhaust outlets

  • Bathroom or kitchen exhaust vents

  • Plumbing vents

  • Vehicle exhaust

  • Generator exhaust

  • Garbage or dumpster areas

  • Loading zones

  • Outdoor smoking areas

  • Areas where lawn chemicals or pesticides may be used

  • Standing water or drainage areas

Fresh-air intakes should also be located where they are less likely to be blocked by landscaping, leaves, snow, or other debris.

The exact clearances depend on the applicable code, equipment manufacturer, and project design requirements, so those should always be checked before installation.

Why Should Fresh-Air Intakes Be Separated From Exhaust Vents?

If a fresh-air intake is located too close to an exhaust termination, some of the air being discharged from the building can be drawn directly back into the ventilation system.

That can reduce ventilation effectiveness and potentially bring odors, moisture, lint, or other contaminants back indoors.

This is especially important near:

  • Bathroom exhaust

  • Kitchen exhaust

  • Dryer exhaust

  • ERV or HRV exhaust outlets

  • Other mechanical exhaust systems

The goal is to provide enough separation so the incoming air is truly fresh outdoor air, not recently exhausted building air.

Does a Fresh-Air Intake Need a Screen?

Yes, fresh-air intake terminations generally need screening or similar protection to help prevent insects, leaves, and debris from being drawn into the ventilation system.

This is different from clothes-dryer exhaust terminations, where screens should not be used because lint can accumulate and restrict airflow.

A purpose-built intake vent such as FreshVent is designed with fresh-air applications in mind, including the need for exterior protection while maintaining airflow.

The screen or intake opening should still be inspected periodically because dirt, pollen, insects, or debris can gradually reduce airflow.

What Size Fresh-Air Intake Vent Do I Need?

The correct intake size depends on the duct size and airflow requirements of the ventilation equipment.

Fresh-air intake vents should not be selected only by exterior appearance. The termination needs to provide enough free area so it does not create unnecessary restriction for the ERV, HRV, or make-up-air system.

FreshVent is available in common 4-inch and 6-inch sizes, making it suitable for a range of residential and light-commercial ventilation applications.

Before ordering, confirm:

  • Equipment connection size

  • Required airflow

  • Duct diameter

  • Manufacturer installation instructions

  • Exterior termination requirements

  • Applicable local code requirements

What Is FreshVent?

FreshVent is an exterior wall termination designed specifically for fresh-air intake applications rather than dryer or general exhaust.

It can be used with systems such as:

  • ERVs

  • HRVs

  • Dedicated fresh-air ventilation systems

  • Make-up-air systems

  • Other mechanical outside-air applications

FreshVent provides a finished exterior intake point while helping protect the duct opening from weather, insects, and debris.

This application-specific design is important because a fresh-air intake performs a very different job from an exhaust vent: instead of pushing indoor air outside, the system is intentionally pulling outdoor air into the building.

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What Is Make-Up Air?

Make-up air is outdoor air intentionally brought into a building to replace air that is being removed by exhaust systems.

For example, kitchen exhaust equipment, bathroom fans, dryers, and other mechanical exhaust systems can remove air from a building. In tighter construction, that exhausted air may need to be replaced through a controlled make-up-air system.

A make-up-air system can help reduce excessive negative pressure and provide a more intentional path for replacement outdoor air.

The amount of make-up air required depends on the building, exhaust equipment, applicable code requirements, and system design.

When a make-up-air system draws outdoor air through an exterior wall, a purpose-built intake termination such as FreshVent can provide the exterior connection.

Fresh-Air Intake vs. Make-Up Air: Are They the Same Thing?

The terms are sometimes used interchangeably, but they do not always describe the exact same purpose.

Fresh-air ventilation is generally intended to provide controlled outdoor air for indoor air quality.

Make-up air is generally intended to replace air removed by mechanical exhaust and help manage building pressure.

An ERV or HRV may provide balanced ventilation by bringing outdoor air in while exhausting indoor air at approximately the same time.

A dedicated make-up-air system, on the other hand, may operate specifically in response to exhaust equipment.

Both applications may require an exterior outdoor-air intake, which is why the same intake termination can be useful across several ventilation-system types.

Where Should FreshVent Be Installed?

FreshVent should be installed where it can draw clean outdoor air while remaining accessible for inspection and maintenance.

When choosing the location, consider:

  • Separation from exhaust outlets

  • Distance from dryer vents

  • Nearby bathroom or kitchen exhaust

  • Vehicle or generator exhaust

  • Landscaping and vegetation

  • Snow accumulation

  • Splashing or drainage

  • Accessibility for cleaning

  • Duct routing back to the ventilation equipment

The goal is to provide the ventilation system with a clean, unobstructed outdoor-air source.

Equipment-manufacturer instructions, project documents, and applicable local codes should always be reviewed when determining the final location.

How Do You Maintain a Fresh-Air Intake Vent?

Because outdoor air is constantly being drawn through the intake, the exterior termination should be inspected periodically.

Look for:

  • Leaves

  • Pollen

  • Dirt

  • Insects

  • Spider webs

  • Landscaping debris

  • Snow or ice

  • Damage to the screen or vent body

A partially blocked intake can reduce the amount of outdoor air reaching the ventilation equipment and make the system work harder than intended.

The ERV, HRV, or ventilation equipment filters should also be inspected and replaced or cleaned according to the manufacturer's maintenance instructions.

Can You Use an Exhaust Wall Vent as a Fresh-Air Intake?

Not every exhaust termination is appropriate for use as a fresh-air intake.

An exhaust vent is designed primarily to let air leave the building, often using a damper that opens when air pushes outward.

A fresh-air intake needs to allow air to enter freely while providing appropriate protection from rain, insects, and debris.

Using a purpose-built intake termination such as FreshVent removes much of that uncertainty because the product is designed specifically for incoming outdoor air.

Shop Fresh-Air Intake Solutions

Solid Source HVAC offers FreshVent exterior intake solutions for ERV, HRV, fresh-air, and make-up-air applications.

4-inch FreshVent
A compact option for ventilation systems using 4-inch outside-air ductwork.

6-inch FreshVent
Designed for systems requiring a larger 6-inch intake connection and greater airflow capacity.

Before ordering, confirm the duct size and airflow requirements of your specific ventilation equipment.

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Choosing the Right Fresh-Air Intake Starts With the System

A fresh-air intake is more than an opening in the exterior wall. It is the point where the building's mechanical ventilation system connects to the outdoor environment.

The correct termination should provide adequate airflow, weather protection, insect and debris protection, appropriate placement, and compatibility with the ventilation equipment.

Whether the system uses an ERV, HRV, dedicated fresh-air system, or make-up air, selecting a purpose-built exterior intake such as FreshVent can help create a cleaner and more durable installation.

For additional information on selecting exterior intake and exhaust terminations, read our Exterior Wall Vent Guide.

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