HVAC Piping System & Design

A: Expansion loop geometry is driven by expected linear expansion, which depends on pipe material coefficient and design temperature swing. Pressure and velocity affect support and erosion concerns but do not set loop dimensions.

A: HDPE is chemically inert to most tower water conditions and avoids under-deposit corrosion seen in metallic systems. While carbon steel coatings delay failure, coating damage during install often becomes the corrosion initiation point.

A: Equal friction assumes uniform pressure drop per length, which can create branch imbalance when fittings and valve losses vary significantly. Supplemental balancing or detailed branch analysis is required to avoid control instability.

A: Zoning the system with pressure-reducing valves limits downstream static pressure, keeping terminal equipment within rating and reducing valve authority issues. Material strength alone does not address control and leakage failures at coils.

A: Discontinuities in the vapor barrier allow moisture ingress, saturating insulation and driving surface condensation. This degrades thermal performance and creates downstream corrosion and mold risks.

A: Closely spaced tees rely on minimal pressure drop between connections; increasing spacing introduces differential pressure that drives unintended flow between loops, bypassing the load.

A: Rigid anchors fully restrain axial movement and must be intentionally located. Overuse leads to stress accumulation and joint failure as the system heats and cools.

A: Glycol increases fluid viscosity, significantly raising friction losses at low temperatures. If not corrected during design, pumps fail to deliver required flow under peak winter conditions.

A: A staged approach removes construction debris first, then dissolves residues, followed by a clean final flush. Leaving strainers in during final flushing often reintroduces trapped debris into the system.