What are the four factors that a single-family Mechanical Ventilation Rate (MVR) depends on?

The correct answer identifies four key factors that influence a single-family Mechanical Ventilation Rate (MVR): climate, number of occupants, building height, and shielding from the wind. Each of these factors plays a crucial role in determining how much mechanical ventilation is necessary to ensure adequate indoor air quality and comfort.

Climate affects the ventilation needs because different weather conditions impact the humidity and temperature inside the home. For instance, areas with high humidity may require a different ventilation strategy than dryer climates to prevent moisture issues.

The number of occupants is significant because more people generate more pollutants, carbon dioxide, and humidity, requiring additional ventilation to maintain a healthy indoor environment.

Building height can influence MVR because taller structures may experience different wind pressures and air exchange rates compared to shorter buildings, which can alter how effectively outdoor air is brought into the living space.

Finally, shielding from the wind, such as nearby structures or landscape features, can affect how air moves around the building and, therefore, how much ventilation is necessary. Well-shielded buildings may have different air exchange rates compared to those exposed to more wind.

These factors must be considered collectively to determine the appropriate MVR needed for the effective ventilation of a home.