If a salon lacks an exhaust system, what must be kept on during business hours?

In a salon without an exhaust system, keeping the thermostat fan switch on during business hours is crucial for maintaining proper air circulation. The fan helps in circulating air throughout the establishment, which can reduce the buildup of fumes and chemicals commonly found in beauty treatments, such as those used for eyelash extensions. This circulation is important for both client and technician safety as it minimizes the potential for respiratory irritation and creates a more comfortable environment.

While heating, ventilation, and air conditioning systems can contribute to air quality, the primary function of the thermostat fan switch is to ensure consistent airflow, even when the temperature control aspects of those systems are not engaged. By relying on the fan, you can help alleviate the stagnation that could occur in a closed environment, which is especially important in a salon setting where various products are used.

Keeping lights on does not impact air quality or circulation and therefore is not relevant in this context.