4th Steam Practice Test

The main idea here is energy use and overall system performance. The biggest disadvantage of the DDCV venting system is inefficiency—meaning the system uses more energy than necessary to move air and achieve the desired ventilation. That extra energy shows up as higher operating costs and potential heat loss or gain, which can worsen comfort and increase utility bills over time. Even if other factors like noise, installation cost, or maintenance come into play, they don’t have the same lasting impact on running costs and performance as ongoing energy waste. So the enduring drawback is the wasted energy that comes with inefficiency.