An HRV system that creates an indoor-outdoor pressure difference is described as which type?

An HRV system that creates an indoor-outdoor pressure difference is described as which type?

• A. Unbalanced system
• B. Balanced system
• C. Mechanical-only
• D. Passive system

Answer: (A)

An HRV’s function is to move air in and out through two paths. Whether this exchange changes indoor pressure depends on how well the two air flows are matched. When the supply and exhaust are balanced, the net air moved in or out is about the same, so indoor pressure stays roughly equal to outdoor pressure. If the system creates a pressure difference, the flows aren’t equal, causing the indoors to become slightly negative or positive relative to outdoors. That’s what’s meant by an unbalanced system. So, describing the HRV as creating an indoor-outdoor pressure difference points to it being unbalanced. A balanced system would keep pressure nearly equal, a mechanical-only setup would focus on the presence of heat recovery or lack thereof rather than the pressure balance, and a passive system relies on natural forces rather than a fan-driven exchange.

An HRV’s function is to move air in and out through two paths. Whether this exchange changes indoor pressure depends on how well the two air flows are matched. When the supply and exhaust are balanced, the net air moved in or out is about the same, so indoor pressure stays roughly equal to outdoor pressure. If the system creates a pressure difference, the flows aren’t equal, causing the indoors to become slightly negative or positive relative to outdoors. That’s what’s meant by an unbalanced system. So, describing the HRV as creating an indoor-outdoor pressure difference points to it being unbalanced. A balanced system would keep pressure nearly equal, a mechanical-only setup would focus on the presence of heat recovery or lack thereof rather than the pressure balance, and a passive system relies on natural forces rather than a fan-driven exchange.