The circulation of air throughout a building is ventilation. The ventilation of a commercial property relies heavily on the HVAC system. A good HVAC system should provide air to building occupants at a comfortable temperature, at comfortable humidity levels and be free of harmful concentrations of air pollutants.
Improper operation and maintenance of HVAC systems are the most common problems that impact workplace indoor environmental quality (IEQ).
The heating & air systems serve to dilute and remove contaminants from occupied areas, such as:
- carbon dioxide and carbon monoxide
- tobacco smoke
- molds and bacteria
- cleaning products
- copy machines and printers
- vehicle exhaust
There are three basic elements to building ventilation:
1. Ventilation Rate. The amount of outdoor air that is provided into the space, and the quality of the outdoor air
2. Airflow Direction. The overall airflow direction in a building, which should be from clean zones to dirty zones
3. Airflow Pattern. The external air should be delivered to each part of the space efficiently and the airborne pollutants generated in each part of the space should also be removed efficiently.
Mechanical ventilation that is driven by fans and hybrid ventilation systems are the most common types of ventilation in Central Ohio.
With mechanical ventilation, fans can either be installed directly in windows or walls, or installed in air ducts for supplying air into or exhausting air from a room.
The type of mechanical ventilation used depends on the climate. In cold climates, exfiltration needs to be prevented to reduce interstitial condensation, and negative pressure ventilation is used. For a room with locally generated pollutants, such as a bathroom, toilet or kitchen, the negative pressure system is often used. In a negative pressure system, the room is in negative pressure, and the room air is compensated by “sucking” air from outside.
Hybrid ventilation relies on natural driving forces to provide the desired flow rate. It uses mechanical ventilation when the natural ventilation flow rate is too low.
If natural ventilation alone is not suitable, exhaust fans can be installed to increase ventilation rates. This type of hybrid (mixed-mode) ventilation needs to be used with care. The fans should be installed where room air can be exhausted directly to the outdoor environment through either a wall or the roof. The size and number of exhaust fans depend on the targeted ventilation rate and should be measured and tested before use.
The use of exhaust fans can have issues such as difficulty installing large fans, noise especially from high-power fans, increased or decreased temperature in the space and the need for a non-stop electricity supply. If the environment in the space causes thermal discomfort, spot cooling or heating systems and ceiling fans can be added.
Ohio Heating provides a broad range of ventilation and airflow control products for commercial projects. We have systems that can drastically reduce energy consumption and improve the overall indoor air quality of your commercial space. Give us a call at 614-863-6666 to learn more.