Every building has pressure, just like every company has a culture, positive or negative. Building pressure is measured relative to outdoor pressure. Pressure differential is the difference between the pressure of one location to another. Ideally, you want a positive differential in your building, about +0.02” w.c. to +0.05” w.c. greater than outdoors. Why positive? Positive pressure keeps drafts from coming in through door and window cracks, among other benefits. LONG partners with many manufacturers who offer products to help determine pressure differential in locations. Click here to see how air pressure transmitters can help.

What keeps your building positive? The V in HVAC – Ventilation! Ventilation typically is a function of your unit’s economizer. Economizers are the dampers that control how much outdoor air is introduced into the building through the HVAC system. This ventilation air is also known as fresh air.

In large buildings, supply air fans run continuously when the building is occupied. Buildings with smaller RTUs may have a programable room thermostat with smart fan technology or a switch for fan on or auto. Flipping the switch to on will give you continuous ventilation and the benefits of a positive building.

Keeping your building healthy means to be under positive pressure, providing ventilation, and continuous fresh air. LONG’s HVAC Service teams can help ensure that happens with preventative maintenance or repairs when needed. If you need help finding out if your building has positive pressure or if you need to improve ventilation, reach out to us today.