Whole House Ventilation System: What It Is, Types, Costs

A whole-house ventilation system uses dedicated fans, ducts, and controls to continually replace stale indoor air with fresh outdoor air at a measured rate. Unlike a bath fan or cracking windows, it circulates air through the whole home on purpose—diluting pollutants and odors and helping manage moisture. Some designs also recover heat (and sometimes humidity) from outgoing air, so you get ventilation with far less energy waste.

In this guide, you’ll learn how these systems work, the benefits to expect, and the four main types—exhaust, supply, balanced, and energy/heat recovery (HRV/ERV)—plus HRV vs. ERV. We’ll cover climate-specific picks, sizing basics (ASHRAE 62.2), real-world costs, design and installation tips, maintenance, and how ventilation compares to—and pairs with—whole house fans.

How a whole house ventilation system works

A whole house ventilation system uses dedicated fans, ducts, and controls to bring filtered outdoor air into living spaces while exhausting stale air from kitchens, baths, and other source areas. In exhaust-only setups the house is slightly depressurized; supply-only systems lightly pressurize it; balanced systems use two fans to move equal airflows. HRV/ERV units add a heat exchanger core that transfers energy between outgoing and incoming airstreams—often recovering about 70%–80%—and ERVs also transfer some moisture, helping stabilize indoor humidity. Controls can run continuously or on timers to meet target ventilation rates.

Benefits you can expect

Add a whole house ventilation system and you’ll feel fresher air daily—and protect your home for the long haul. Ventilation is measured, even, and designed to work year‑round.

• Better IAQ: Continuously dilutes pollutants and cooking odors; supply and balanced systems let you filter incoming air.
• Humidity control: ERVs transfer moisture, reducing condensation and mold risk.
• Efficiency: HRV/ERV cores recover roughly 70%–80% of exhaust energy.
• Safety and code: Reduces combustion backdrafting risk and supports code compliance.

The four main types of systems explained

When you choose a whole house ventilation system, you’re really choosing how fresh air gets in and stale air gets out. Each approach manages pressure, moisture, and energy differently—so climate and goals (IAQ, efficiency, cost) should guide the pick.

• Exhaust (depressurizes): Simple, low-cost. Best in cold climates. Can draw pollutants from crawlspaces/garages and risk backdrafting; not suited to hot, humid climates.
• Supply (pressurizes): Better control of intake air; can filter and help dehumidify; prevents backdrafting. Works well in hot or mixed climates. Can cause moisture issues in cold climates.
• Balanced (neutral): Two fans/ducts supply and exhaust similar volumes; allows filtration; appropriate for all climates. Higher install/operating cost; doesn’t condition incoming air.
• Energy/Heat Recovery (ERV/HRV): Balanced with a heat exchanger to reduce heating/cooling costs; often most cost‑effective in extreme climates. Higher upfront cost, needs frost protection in cold regions and regular maintenance.

HRV vs ERV: what’s the difference?

Both HRVs and ERVs are balanced whole-house ventilation systems with a heat‑exchange core that recovers much of the energy in exhaust air (often about 70%–80%). The difference is moisture: an ERV’s core transfers some water vapor along with heat, while an HRV transfers heat only. That single detail drives how each manages indoor humidity, frosting risk, and summer comfort.

• HRV (heat only): Purges indoor moisture more aggressively in winter; often favored in cold, dry climates. May require frost protection in very cold weather.
• ERV (heat + some moisture): Helps keep winter humidity steadier and, in summer, shifts some moisture from incoming air to the exhaust stream—improving humidity control when the AC runs. The warmer core also minimizes freezing concerns.
• Maintenance: Both need periodic filter and core cleaning; follow manufacturer schedules.

Next, match the choice to your climate.

Climate-by-climate recommendations

Your climate should drive your whole house ventilation system choice because temperature and humidity affect pressure, moisture risk, and energy payback. Per DOE guidance, exhaust favors cold regions; supply favors hot/mixed; balanced works anywhere; and HRV/ERV units shine where winters or summers are extreme and energy costs are high.

• Cold/Very cold: Prefer balanced or HRV; add frost protection. Exhaust-only can work but watch for backdrafting. Avoid supply-only (wall moisture risk).
• Mixed (four-season): Balanced or ERV for year-round control; supply-only can be acceptable with winter safeguards.
• Hot-humid: Choose ERV or supply; avoid exhaust-only (it pulls moist air into cavities). Include filtration and humidity lockouts.
• Hot-dry: Supply or balanced; energy recovery is optional—ERV moisture transfer offers little benefit here.
• Marine/mild: Balanced or timed supply; HRV/ERV may not be cost-effective in mild conditions.

How to choose the right system for your home

Start with your climate and how tight your home is, then weigh moisture risks, energy goals, and installation realities. In cold regions, avoid strategies that push warm, humid air into walls; in hot‑humid areas, avoid systems that pull moist air through the shell. Balanced systems fit any climate, while HRV vs. ERV depends on humidity needs.

• Climate fit: Cold = balanced/HRV; hot‑humid = supply/ERV; mild = balanced or timed supply; extreme seasons favor HRV/ERV payback.
• Combustion safety: If you have fireplaces or fossil‑fuel appliances, avoid depressurizing; favor supply or balanced.
• IAQ priorities: Need filtration or humidity moderation? Choose supply/balanced; pick ERV to stabilize humidity or HRV to purge moisture.
• Ducts and layout: Ensure space for short, straight runs; plan dedicated vents to bedrooms and wet rooms.
• Cost, maintenance, and code: HRV/ERVs cost more and need frost protection and regular cleaning; experienced installers can be harder to find. Verify airflow meets ASHRAE 62.2 and local code.

Costs: equipment, installation, and operating

Think about cost in three buckets: equipment, installation, and ongoing energy/maintenance. Per DOE guidance, exhaust and supply systems are relatively inexpensive and simple to install; balanced systems cost more; and HRV/ERV units have the highest upfronts. HRV/ERVs can cut heating/cooling loads by recovering about 70%–80% of exhaust energy, but their fans add electricity use—typically most cost‑effective in climates with extreme winters or summers.

• Equipment: Exhaust/supply = lowest; balanced = higher; HRV/ERV = highest.
• Installation: Two fans/ducts increase labor; simpler designs or shared ductwork lower costs.
• Operating: HRV/ERV save conditioning energy but add fan power; mild climates may see limited net savings.
• Maintenance: HRV/ERV need regular filter/core cleaning and frost protection in cold regions.

Sizing and code basics (ASHRAE 62.2)

Use ASHRAE 62.2 as your baseline for sizing a whole house ventilation system. The standard defines minimum whole‑house and local exhaust ventilation rates and lets you meet them with continuous or timed operation. Because compliance is calculation‑ and measurement‑based, have an HVAC pro determine the target CFM, size ducts, and commission the system to verify delivered airflow.

• Airflow placement: Supply to bedrooms/living; exhaust from kitchen/baths.
• Duct quality: Keep runs short/straight; right‑size; seal with mastic; insulate in unconditioned spaces.
• Cold climates: Provide HRV/ERV frost protection; avoid depressurizing homes with combustion appliances.

Installation and design best practices

A good whole house ventilation system starts with smart design and careful commissioning. Aim for controlled, even airflow where people live, and source removal where pollutants are created. Keep the layout simple to limit pressure losses and noise, and choose controls that match your climate and comfort goals.

• Place vents wisely: Supply fresh air to bedrooms and living rooms; exhaust from kitchens, baths, and laundry. Avoid relying on random leakage; passive inlets often need higher pressure to work well.
• Build tight, flow right: Keep duct runs short and straight, size correctly to minimize pressure drop, seal all joints with duct mastic, and insulate ducts in unconditioned spaces.
• Balance and verify: For balanced/HRV/ERV systems, match supply and exhaust flows and commission to the target CFM.
• Filter and temper: Filter outdoor air on supply/balanced systems. Mix incoming air to prevent winter drafts; in-line duct heaters are an option but raise operating cost.
• Protect in cold climates: Provide HRV/ERV freeze/frost protection to prevent core damage and performance loss.
• Prioritize safety: Avoid depressurizing homes with fireplaces or fossil-fuel appliances to reduce backdrafting risk; favor supply or balanced strategies.
• Use smart controls: Run continuously or on timers to meet ventilation rates; in very humid weather, use temperature/humidity lockouts or interlock operation with the AC.

Maintenance and lifespan

Whole-house ventilation stays reliable when it’s kept clean and balanced. Exhaust and supply systems need little attention, while HRV/ERV units require more: their filters and heat‑exchange cores must be cleaned regularly to preserve airflow, energy recovery, and hygiene. In cold climates, verify frost/defrost protection. With routine cleaning and basic repairs, systems provide long service life; actual lifespan depends on climate, run time, and maintenance.

• Replace/wash filters on schedule; clean the HRV/ERV core.
• Clear intake/exhaust hoods, screens, and condensate/drain lines.
• Recheck airflow balance and duct seals after any HVAC work.

Whole house ventilation vs whole house fan (and how they work together)

These two tools do different jobs. A whole house ventilation system delivers measured, year‑round fresh air for IAQ and moisture control (often balanced or HRV/ERV). A whole house fan is a high‑airflow cooling appliance: with windows open, it pulls cooler outdoor air through the home and exhausts hot, stale air up and out—flushing heat quickly in the evening or morning. Use ventilation for steady, code‑level air exchange; use the fan for fast, low‑cost comfort when weather cooperates.

• Whole‑house ventilation: Continuous, controlled airflow; supports filtration and humidity management; all‑season use.
• Whole‑house fan: Rapid whole‑home cooling; best when outside air is cooler/drier; not ideal during hot, humid hours.
• Together: Run ventilation on schedule year‑round; run the fan when conditions are right. Modern insulated, quiet fans help minimize noise and energy loss when off.

Alternatives and add-ons for better IAQ

If you’re not ready for a new whole house ventilation system—or want to boost the one you have—these proven add-ons can dramatically improve indoor air quality. Use them to target moisture, odors, and particles, and to fine‑tune how and when outside air enters. When weather cooperates, simple window ventilation can also help.

• Spot ventilation: Duct bath and range hoods outdoors to capture moisture and pollutants.
• Filtration upgrades: Use MERV 8–13 on supply/balanced or HRV/ERV intakes.
• Humidity control: Add a whole‑house dehumidifier (or a humidifier in dry winters)—seal leaks first.
• Smart controls: Interlock fans with HVAC, set temperature/humidity lockouts, and timers.
• Source fans: Use quiet attic or garage exhaust fans to purge heat and fumes.

Common pitfalls to avoid

Most ventilation problems come from a mismatch between system type and climate, unmanaged pressure, and “install it and forget it” design. Choose the wrong strategy and you can invite moisture damage, safety issues, and wasted energy. Poor duct layout, lack of commissioning, and skipped maintenance compound the issues.

• Exhaust-only in hot‑humid climates: drives moisture into building cavities.
• Supply-only in cold climates: pushes warm air into walls/attics.
• Depressurizing homes with combustion appliances: backdrafting risk.
• HRV/ERV without frost protection or cleaning: freeze-ups, airflow loss.

Getting started: a quick homeowner checklist

Ready to move from research to action? Use this quick checklist to match a whole house ventilation system and avoid moisture or safety mistakes. Confirm climate fit, airflow, pressure strategy, and duct quality so bids are accurate and installation is smooth.

• Climate: cold = HRV/balanced; hot‑humid = supply/ERV.
• Safety: don’t depressurize fuel‑burning homes.
• Sizing: set CFM to ASHRAE 62.2.
• Ducts: short, sealed, insulated; commission; add filtration/frost.

The bottom line

Whole-house ventilation is planned, measured fresh air—delivered the right way for your climate. Choose the strategy that fits your home: exhaust or supply for simple, lower-cost setups; balanced for all-around control; and HRV/ERV when you want energy savings and steadier humidity. Design it well, commission it to ASHRAE 62.2 airflow, and keep it maintained, and it will quietly protect your air quality, comfort, and building materials for years.

For fast, low-cost cooling when outdoor air is favorable, pair ventilation with a modern, insulated whole house fan. Need help choosing and want whisper‑quiet options? Explore guidance and products at Whole House Fan.