Application Guide.pdf - Emerson Swan

VAV TerminalsVAV terminals are used in a variable air volume system and heat (fan powered) or reheat (single duct) the air to the local needs of temperature.This heat can be provided by a hot water coil. The water flow in this coil is controlled with either modulating or ON/OFF control valve.In modulating systems with a relatively low pump head, the balancing can be performed with a manual or AutoFlow balancing valve. If the pump headis relatively high, then the pressure should be stabilized with differential pressure controller, shared between several hot water coils.ON/OFF systems work extremely well with a flow limiting valve such as AutoFlow or manual terminal valves. If the pump head is relatively high,the pressure should be stabilized with a differential pressure controller on each module.VAV Terminals (single duct shown)VAV TERMINAL OVERVIEWSupplyAirReheatCoilVAV TERMINALSBalancing options modulating control: Rating1. Flow limiting on each panela. ATC + AutoFlow if H < 4 x Δp ATC★★★b. ATC + AutoFlow + DA if H ≥ 4 x Δp ATC★★★2. Pressure stabilizationa. KTM ★★Balancing options ON/OFF control: Rating3. Flow limiting on each panela. ATC + AutoFlow ★★★4. Combination terminal unit valve +shared Dp controllera. TBV-C if H < 15 psi ★★b. TBV-C + DA if H ≥ 15 psi ★★5. Control valve + manualbalancing on each panela. ATC + FlowSet if H < 25 psi ★b. ATC + FlowSet + DA if H ≥ 25 psi ★23