What is the wind velocity used to calculate summer infiltration heat gains?

The correct wind velocity used to calculate summer infiltration heat gains is 12 km/h (7.5 mph). This value is significant in energy modeling and building design because it reflects a realistic average wind speed that may lead to noticeable effects on indoor temperatures through air infiltration during the warmer months. When buildings are assessed for their cooling loads, understanding how much external air can enter and affect interior conditions is crucial. Infiltration can increase the demand for cooling by allowing warm, humid air from outside to mix with the cooler indoor air, thus impacting the overall heating, ventilation, and air conditioning (HVAC) requirements.

Using 12 km/h as a baseline allows engineers to estimate the potential heat gains accurately. This speed serves as a common reference point in many engineering guidelines and standards because it tends to align with typical summer conditions in various regions, making it a practical choice for calculations. In contrast, the other wind velocities may not align with the standard practices set forth in most energy modeling systems for summer conditions, which is why they are not as appropriate for this context.