HRV, ERV, and Makeup Air System Installation
Full Nelson installs heat recovery ventilators (HRV), energy recovery ventilators (ERV), and makeup air (MUA) systems that bring controlled fresh air into your home without losing the energy your heating or cooling system has already produced. These ventilation systems solve the air quality problems that come with tightly sealed homes.
Why Mechanical Ventilation Matters
Modern homes are built tight. Upgraded insulation, sealed building envelopes, and energy-efficient windows reduce heat loss, but they also trap stale air, moisture, CO2, cooking fumes, off-gassing from building materials, and other pollutants inside. Older homes that have been weatherized with added insulation and air sealing face the same issue.
Without a controlled way to exchange indoor air for fresh outdoor air, pollutant concentrations rise over time. CO2 levels climb in bedrooms overnight. Moisture from showers, cooking, and breathing accumulates. VOCs from paint, flooring, furniture, and cleaning products linger. Opening a window works in mild weather but wastes conditioned air in summer and winter.
HRV, ERV, and makeup air systems solve this by providing continuous, controlled ventilation while recovering the energy from the outgoing air stream. Fresh air comes in. Stale air goes out. The energy stays.
Heat Recovery Ventilators (HRV)
An HRV exchanges stale indoor air with fresh outdoor air through a heat exchanger core. The outgoing warm air passes through one side of the core while incoming cold air passes through the other side. The two air streams never mix, but heat transfers through the core material from the warm stream to the cold stream.
In winter, the outgoing heated indoor air warms the incoming cold outdoor air before it enters your home. In summer, the process reverses. The outgoing cooled indoor air pre-cools the incoming hot outdoor air. Recovery efficiencies on modern HRV units range from 70% to 90%, meaning the majority of the energy in the outgoing air is captured and transferred to the incoming air.
HRV systems are well suited for:
- Dry climates or homes that already have adequate humidity control
- Homes with high indoor moisture levels where you want to exhaust humidity rather than retain it
- Cold-climate applications where the primary goal is recovering heating energy from exhaust air
Energy Recovery Ventilators (ERV)
An ERV works like an HRV but adds moisture transfer to the heat exchange process. The core material in an ERV is permeable to water vapor, allowing the system to transfer both heat and humidity between the incoming and outgoing air streams.
In winter, the ERV recovers heat from the outgoing air and also retains some of the indoor moisture, preventing the incoming fresh air from drying out the house. In summer, the ERV removes some moisture from the incoming humid outdoor air before it enters the home, reducing the load on your air conditioning system.
ERV systems are well suited for:
- Humid climates where incoming summer air carries excess moisture
- Homes that struggle with dry indoor air during heating season and want to retain some humidity
- Homes with both heating and cooling demands where year-round moisture management matters
- The Kansas City metro climate, which sees both cold dry winters and hot humid summers
For most homes in the Kansas City metro, an ERV is typically the better fit because the climate has significant humidity swings between seasons. Full Nelson evaluates your home’s specific conditions before recommending one over the other.
Makeup Air (MUA) Systems
Makeup air systems supply fresh outdoor air to replace air that is exhausted from the home by range hoods, bath fans, dryers, and combustion appliances. In a tightly sealed home, a powerful range hood can pull enough air out of the house to create negative pressure. This negative pressure can backdraft gas furnaces, water heaters, and fireplaces, pulling combustion gases including carbon monoxide into the living space instead of up the flue.
Building codes in many jurisdictions now require makeup air for range hoods rated above 400 CFM. A makeup air system provides a controlled pathway for replacement air to enter the home, maintaining neutral or slightly positive pressure and preventing backdrafting.
Makeup air systems can be configured as:
- Passive makeup air dampers: A motorized damper opens when the range hood activates, allowing outdoor air to enter through a dedicated duct. Simple and effective but does not temper the incoming air.
- Tempered makeup air units: Include a heating element that warms the incoming outdoor air before it enters the home. Prevents a blast of cold air in winter when the range hood runs.
- Integrated ERV/HRV with makeup air capability: Some ERV and HRV units can serve double duty, providing continuous balanced ventilation and supplementing makeup air demand when exhaust appliances run.
HRV vs. ERV: Which One Do You Need?
The choice depends on your climate, your home’s moisture characteristics, and what problem you are trying to solve.
- If your home is too humid in winter (condensation on windows, mold in bathrooms): An HRV exhausts that excess moisture rather than transferring it back.
- If your home is too dry in winter (cracking wood, static, dry sinuses): An ERV retains some indoor moisture and prevents the fresh air supply from making the problem worse.
- If summer humidity is a concern: An ERV removes some moisture from the incoming outdoor air, reducing the load on your AC and dehumidifier.
- If your primary concern is CO2 buildup and stale air: Either system solves this. The choice then comes down to moisture management preferences.
Full Nelson evaluates your home’s air sealing, HVAC system, humidity levels, and ventilation needs before recommending a specific system.
Installation
Full Nelson installs HRV, ERV, and makeup air systems by integrating the ventilation unit with your existing HVAC ductwork or by running dedicated ventilation ductwork to specific rooms.
Installation includes:
- Evaluating your home's air sealing, ventilation needs, and HVAC configuration
- Selecting the correct unit capacity based on home size and occupancy
- Mounting the unit and connecting supply and exhaust ductwork
- Running outdoor intake and exhaust ports with proper separation and weather protection
- Connecting condensate drainage from the heat exchanger core
- Wiring controls and interlocking with HVAC blower if integrated into the duct system
- Balancing airflows and testing system performance
For homes with forced-air HVAC systems, the ventilator can be connected to the return duct so that incoming fresh air passes through the furnace filter before entering the living space. Dedicated duct installations route fresh air directly to bedrooms and living areas where air quality matters most.
Maintenance
HRV and ERV systems require periodic maintenance to perform correctly. The heat exchanger core collects dust and needs cleaning. Filters on both the supply and exhaust sides need inspection and replacement. Condensate drains need to be kept clear. Outdoor intake and exhaust hoods need to be checked for blockage from debris, ice, or pest nesting.
Maintenance tasks include:
- Filter inspection and replacement every 3 to 6 months
- Heat exchanger core cleaning annually (most cores are washable)
- Condensate drain inspection and clearing
- Outdoor intake and exhaust hood inspection
- Fan motor and airflow balance verification
Full Nelson services HRV, ERV, and makeup air systems from all major manufacturers.
Why Full Nelson
- Family, Women, and Veteran owned since 2003
- Licensed, insured HVAC technicians
- HRV, ERV, and makeup air system installation
- Integration with existing forced-air HVAC systems
- Up-front pricing before work begins
- 24/7 service