How does proper outdoor air mixing affect mixed-air conditions and system efficiency?

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Multiple Choice

How does proper outdoor air mixing affect mixed-air conditions and system efficiency?

Proper outdoor air mixing ensures the mixed-air entering the system has the intended temperature and humidity. When mixing is effective, the air coming from the outdoor intake and the return air blend smoothly, so the coil loads, humidity control, and any economizer action can be sized and operated efficiently. This predictability means the system meets space conditions with minimal overcooling, reheating, or dehumidification, which reduces energy use and maintains comfort. If mixing is poor, you can end up with uneven or unexpected air conditions, causing the coil to work harder or run longer, and you may need additional reheat or dehumidification to reach setpoints. That extra operation wastes energy and can degrade comfort, even if outdoor air has benefits for IAQ. So the best choice is that accurate mixing yields predictable mixed-air temperature and humidity, and improper mixing can waste energy and impair comfort. Outdoor air mixing does impact energy use, not just IAQ or noise.

Proper outdoor air mixing ensures the mixed-air entering the system has the intended temperature and humidity. When mixing is effective, the air coming from the outdoor intake and the return air blend smoothly, so the coil loads, humidity control, and any economizer action can be sized and operated efficiently. This predictability means the system meets space conditions with minimal overcooling, reheating, or dehumidification, which reduces energy use and maintains comfort.

If mixing is poor, you can end up with uneven or unexpected air conditions, causing the coil to work harder or run longer, and you may need additional reheat or dehumidification to reach setpoints. That extra operation wastes energy and can degrade comfort, even if outdoor air has benefits for IAQ.

So the best choice is that accurate mixing yields predictable mixed-air temperature and humidity, and improper mixing can waste energy and impair comfort. Outdoor air mixing does impact energy use, not just IAQ or noise.

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