Ventilation Systems in Grafton, WI

Ventilation Systems in Grafton, WI

Proper mechanical ventilation is one of the most important upgrades you can make for long term indoor comfort and health in Grafton, WI. Homes here face cold, airtight winters and humid summers near Lake Michigan, which makes controlling indoor moisture and supplying fresh air year round essential.

Why ventilation matters in Grafton homes

Sealing and insulating homes improves comfort and saves energy, but it also reduces natural air exchange. Without mechanical ventilation, pollutants such as VOCs, cooking odors, pet dander, excess humidity, and combustion byproducts can build up. In Grafton, seasonal humidity and cold-weather condensation increase the risk of mold, wood rot, and poor comfort. A properly designed mechanical ventilation system prevents stale air, controls moisture, and reduces the load on heating and cooling equipment while maintaining energy efficiency.

Common ventilation issues in Grafton, WI

• Poor summer humidity control that leads to sticky indoor air and occasional mold in basements and bathrooms.  
• Winter condensation on windows and framing from high indoor moisture levels.  
• Inconsistent indoor air quality in tightly sealed modern homes or after air sealing upgrades.  
• Backdrafting of combustion appliances when older homes rely on exhaust-only ventilation.  
• High energy losses from simple exhaust fans when outdoor air is introduced without energy recovery.

Ventilation system types: ERV, HRV, and balanced systems

Balanced mechanical ventilation brings controlled amounts of fresh outdoor air into the home while removing an equal amount of indoor air. The two most common energy recovery options for balanced ventilation are HRV and ERV.

• Heat Recovery Ventilator (HRV)  
• Transfers sensible heat between incoming and outgoing air streams.  
• Best for cold climates where reducing winter heat loss is the priority.  
• Helps maintain indoor temperatures with minimal heat penalty.
• Energy Recovery Ventilator (ERV)  
• Transfers both heat and some moisture between air streams.  
• Effective in climates with humid summers and cold winters, like Grafton, because it reduces summer moisture load and controls winter dryness.  
• Can prevent bringing excessive outdoor humidity into the home in summer and conserve indoor moisture during winter.
• Balanced ventilation without recovery  
• Simpler systems that bring in fresh air and exhaust indoor air in equal measure.  
• Less energy efficient because they do not transfer heat or moisture between air streams.  
• Sometimes used in specific retrofit situations where recovery is impractical.

How energy recovery works

ERVs and HRVs use a core that allows heat and, for ERVs, limited moisture exchange between the outgoing stale air and incoming fresh air. In winter, the system captures warmth from exhaust air and preheats incoming air, reducing the work the furnace or heat pump must do. In summer, an ERV can reduce the moisture content of incoming humid air by exchanging it with drier indoor air, lowering the cooling system load. Properly sized and controlled, these units maintain ventilation rates required by modern building standards while minimizing energy penalties.

Code and efficiency considerations

• Ventilation rates are commonly guided by ASHRAE 62.2. Systems should meet the recommended cfm per person and per square foot to ensure adequate fresh air.  
• Local codes and the state energy code may reference ASHRAE or the International Energy Conservation Code for mechanical ventilation requirements. A qualified professional will verify compliance during design and installation.  
• Look for ENERGY STAR rated components or high sensible recovery efficiency figures when comparing ERV/HRV units. Higher recovery efficiency reduces running costs and improves overall home comfort.  
• Controls and zoning matter. Use variable speed fans, smart controls, and demand-controlled ventilation where appropriate to match runtime to occupancy and indoor pollutant levels.

System selection and sizing

Selecting the right system depends on home size, occupancy, existing HVAC configuration, and local climate conditions:

• Calculate required ventilation using standards like ASHRAE 62.2, taking into account number of bedrooms and square footage.  
• Choose ERV for homes in Grafton that need year-round humidity management, especially where basements and tight building envelopes are common. HRV can be preferable if winter heat retention is the top priority and interior humidity is normally low.  
• Consider integration with existing HVAC ductwork for central distribution, or use dedicated ducting for point-to-point supply and exhaust in simple homes.  
• Match fan capacity and static pressure ratings to the duct design to ensure the unit can deliver required airflow without excessive noise or wear.

Typical installation overview

• Site assessment: Inspect existing ductwork, combustion appliance ventilation, and typical air leakage paths to determine the best configuration.  
• Unit placement: Install the ERV/HRV in a conditioned space such as a mechanical room or attic with proper condensate drainage and access for maintenance.  
• Duct layout: Provide balanced supply and exhaust paths to key spaces—typically bedrooms and living areas for supply, kitchens and bathrooms for exhaust. Keep duct runs short and minimize sharp bends for efficiency.  
• Controls and integration: Install timers, humidity sensors, or occupancy overrides. Integrate with the home HVAC system if the design calls for preconditioning of incoming air through the furnace or air handler.  
• Commissioning: Verify airflows, ensure the unit is properly balanced, and confirm recovery function and control settings for the local climate.

Maintenance tips to ensure lasting performance

• Clean or replace filters every 3 to 12 months depending on usage and filter type. Clogged filters reduce airflow and recovery efficiency.  
• Inspect and clean the heat or energy exchange core annually. Dust and debris lower transfer efficiency and can cause odors.  
• Check condensate drains (especially in HRVs and ERVs) to prevent blockages that can cause freezing or water damage in cold weather.  
• Verify fan speeds and dampers seasonally to ensure the unit delivers design airflow rates.  
• Keep intake and exhaust grilles clear of leaves, snow, and ice; in winter, protect outdoor intakes from snow drift or ice build up.

Benefits and long-term considerations

A properly specified ERV or HRV balanced ventilation system reduces moisture problems, improves indoor air quality, and can lower overall HVAC energy use in Grafton homes. Beyond immediate comfort and health gains, ventilation systems protect building assemblies from moisture-related damage and can extend the life of insulation and finishes. When selecting and installing a system, prioritize correct sizing, efficient recovery performance, and accessible maintenance. Over time, the right system pays back through improved comfort, fewer moisture issues, and better indoor air quality for your household.