Originally published October 30, 2020 | Last updated: June 15, 2026
PRAIRIE DU SAC, WI — Prompted by pandemic-related safety concerns ahead of a major election, Town of Prairie du Sac officials acted proactively to protect voters entering the municipal Town Hall. To protect election workers and community members from airborne pathogens, the Town Board moved beyond standard surface cleaning protocols to execute a comprehensive mechanical ventilation retrofit of its 1,500-square-foot polling venue.
By integrating dedicated outdoor air technology and advanced ultraviolet disinfection into the facility’s existing HVAC system, local leaders turned the polling site into a model for public health and indoor air quality (IAQ).
The Power of 100% Fresh Air: Focusing on the EV Premium L
To meet the demanding ventilation needs of a heavily populated voting space, mechanical contractor Dischler Heating, Cooling & Fireplaces Inc. retrofitted the town hall’s central system with a high-capacity RenewAire EV Premium L energy recovery ventilator (ERV).
Operating across an efficient airflow spectrum of 30–280 CFM, the EV Premium L allowed the facility to shift seamlessly into an optimized “outdoor air mode.” This dedicated sequence could be activated instantly via a remote hardware switch or responsive occupancy sensors whenever crowds began to gather.
The EV Premium L delivered multi-layered air optimization to the space:
True Pathogen Dilution: The unit continuously flushes out stagnant, recirculated air, replacing it with 100% fresh outdoor air to safely dilute potential viral loads.
Eco-Friendly Energy Recovery: Utilizing an advanced L-50-G5 static-plate core made from specialized cellulosic material, the ERV transfers heat and moisture between airstreams to pre-condition incoming air. This ensured massive fresh-air volume without spiking the municipality’s utility bills.
Safe, Clean Footprint: Following RenewAire’s strict sustainability standards, the built-in core contains no PVCs or halogenated flame retardants, eliminating the risk of stream cross-contamination.
To form a complete environmental defense system, the EV Premium L’s quiet, EC motorized impellers drew outside air through an optional MERV 13 high-efficiency particulate filter, while a downstream PremierOne ultraviolet germicidal irradiation (UVGI) light kit inactivated passing microorganisms inside the ductwork.
Civic Leadership on Indoor Air Quality
The decision to completely modernize the building’s breathing profile stemmed from a shared commitment to modern public safety standards. The multi-layered approach chosen by the Town Board directly mirrors the technical recommendations established by national engineering and safety bodies, including ASHRAE and OSHA.
The immediate impact on the community was clear. As Janine Godfriaux-Leystra, chairperson of Prairie du Sac’s Town Board, stated to reporters:
“We set out to create a healthy, safe environment that offered the best possible protection against airborne contaminants for Election Day and beyond. This complements our election workers’ training in surface disinfection, plus mask, personal hygiene, and physical-distancing in the polling place.”
By implementing this forward-thinking infrastructure, local staff, election volunteers, and town residents secured a permanent, reliable strategy for clean air and public safety
Frequently Asked Questions (FAQs)
How does a balanced ventilation system help dilute indoor airborne pathogens like COVID-19 or RSV?
Viruses like COVID-19 and RSV travel through the air in tiny aerosol droplets that quickly accumulate in enclosed spaces. Traditional HVAC systems often recirculate this contaminated indoor air, shifting viral particles across the breathing zone. A balanced mechanical ventilation system continuously extracts this stagnant, pathogen-heavy air from the room and replaces it with 100% fresh, filtered outdoor air—permanently diluting the concentration of infectious particles and flushing them out of the building.
To learn more about how to use ventilation and filtration to guard against pathogens, visit these sources:
The ASHRAE Epidemic Task Force: Review the ASHRAE Position Document on Infectious Aerosols, which recommends increased outdoor air ventilation as a core strategy to reduce indoor viral loads.
OSHA Workplace Standards: See the OSHA Guidance on Mitigating and Preventing the Spread of COVID-19 in the Workplace, which highlights optimizing mechanical ventilation and bringing in maximum outdoor air to safeguard indoor environments.
RenewAire Technical Research: For a deeper dive into how to use ventilation and filtration as a safeguard against the coronavirus, please read our white paper, 3 Keys to Countering Covid-19.
How does an energy recovery ventilator (ERV) keep utility bills low while introducing fresh air?
Conditioning raw outdoor air normally places a massive energy load on a building’s heating and cooling systems. A RenewAire ERV prevents this by utilizing a static-plate core to exchange energy between the outgoing and incoming airstreams. Using balanced airflows, the ERV recovers and transfers otherwise-expended total energy—both heat (sensible energy) and humidity (latent energy)—to temper the incoming outdoor air:
Summer Operation: Warm, humid outdoor air is pre-cooled and dehumidified by the outgoing, conditioned exhaust air.
Winter Operation: Cold, dry outdoor air is preheated and humidified by the outgoing, warm interior exhaust air.
By pre-conditioning the incoming air this way, the ERV significantly lowers the heating and cooling demands on the primary HVAC infrastructure, allowing the facility to maximize fresh air volume without spiking municipal utility bills.
If outdoor air is needed to clear stale room air of contaminants, why isn't simply opening a window a viable strategy?
While opening a window brings in outdoor air, it represents unregulated, natural ventilation that creates three major challenges:
No Control Over Contaminants: Open windows invite outdoor pollutants—like pollen, dust, smoke, and outdoor particulates—directly into the breathing zone with zero filtration.
Loss of Energy and Comfort: Raw outdoor air forces primary heating and cooling systems to work overtime to correct extreme indoor temperatures and humidity levels, causing utility bills to skyrocket.
Unbalanced Airflow: Natural ventilation relies entirely on unpredictable wind and pressure differences, meaning it cannot guarantee a consistent, high-volume change of air throughout a crowded room.
The RenewAire EV Premium L solves this by providing controlled, balanced ventilation. It utilizes quiet, powerful EC motorized impellers to pull fresh air through optional high-efficiency MERV 13 filtration layers while simultaneously recovering thermal energy from the outgoing exhaust air—ensuring the space stays comfortable, efficient, and thoroughly filtered regardless of the weather outside.