For all air handled by a direct-fired makeup air heater, from where shall it be drawn?

For all air handled by a direct-fired makeup air heater, from where shall it be drawn?

• A. the space being heated
• B. outdoors
• C. the dining room
• D. the kitchen

Answer: (B)

The main idea is that makeup air is fresh air brought in to replace what’s lost to exhaust, and a direct-fired makeup air heater is designed to condition outdoor air before it enters the space. Drawing the air from outdoors ensures you’re adding new, clean air to the building and not re circulating indoor air, which helps maintain proper ventilation, pressure balance, and indoor air quality. If the air came from inside the space being heated, it wouldn’t provide true makeup air and could worsen pressurization and contaminant buildup. The other indoor sources (a space or rooms inside the building) aren’t appropriate because they don’t supply fresh outdoor air and can disrupt ventilation and comfort.

The main idea is that makeup air is fresh air brought in to replace what’s lost to exhaust, and a direct-fired makeup air heater is designed to condition outdoor air before it enters the space. Drawing the air from outdoors ensures you’re adding new, clean air to the building and not re circulating indoor air, which helps maintain proper ventilation, pressure balance, and indoor air quality. If the air came from inside the space being heated, it wouldn’t provide true makeup air and could worsen pressurization and contaminant buildup. The other indoor sources (a space or rooms inside the building) aren’t appropriate because they don’t supply fresh outdoor air and can disrupt ventilation and comfort.