AHI Carrier Catalog | Page 485

DUCTABLE AIR-TO-WATER HEAT PUMPS  30RQSY 039-160 Variable water flow system (VWF) The VWF not only ensures control at full load, a specific Carrier algorithm linked to an electronic frequency converter also continuously modulates the flow rate to minimise pump consumption at full load as well as part load. The hydronic module includes pressure transducers that permit intelligent measurement of the water flow rate and real-time display on the Touch Pilot Junior interface. All adjustments can be made directly on the interface, speeding up start-up and maintenance. 1 – Constant unit outlet pressure control The control continuously acts on the pump speed to ensure a constant outlet pressure. This solution is suitable for installations with two-way valves. When these close, the water speed will accelerate in the system branches that are still open. For a fixed-speed pump this results in an unnecessary increase of the pressure at the pump outlet. The outlet pressure control mode ensures that each circuit branch always has a uniform supply, without unnecessary energy waste. As VWF acts directly on the pump, the system no longer requires the control valve at the unit outlet. However, for applications with two-way valves a bypass system must be kept to guarantee the minimum flow rate. In industrial processes such as plastic injection moulding, this solution ensures that each terminal unit has the correct pressure supply. Operating logic 2 – Constant delta T control The VWF algorithm maintains a constant delta T no matter what the unit load, reducing the flow rate to the minimum. ■■ Full-load set point The flow rate control at full load uses the Touch Pilot Junior interface, reducing the pump speed. This first control saves energy that would normally be dissipated in the control valve. For example, if the pressure supplied by the pump is reduced by 20% the power consumption of the pump is reduced by the same ratio, compared to a traditional installation. ■■ Operating mode at part load Touch Pilot Junior includes two part-load operating modes: -- Constant outlet pressure control -- Constant delta T control. This solution can be used for systems with two-way or threeway valves and achieves higher energy savings than the “Constant unit outlet pressure control” mode. It is suitable for the majority of comfort applications. HEATING Variable water flow is a hydronic control function package that permits control of the water flow rate. Easy and fast installation ■■ Compressors -- Low-noise scroll compressors with low vibration level -- The compressor assembly is installed on an independent chassis and supported by anti-vibration mountings -- Dynamic suction and discharge piping support, minimising vibration transmission (Carrier patent) ■■ Condenser (30RQSY)/air evaporator -- Vertical condenser coils -- Protection grilles on anti-vibration mountings to protect the heat exchanger against possible shocks (30RQSY 080-160 only). -- Low-noise latest-generation Flying Bird IV fans, made of a composite material (Carrier patent) are now even quieter and do not generate intrusive low-frequency noise -- Fan motor controlled by a variable-frequency controller, to allow adjustment of the fan speed in accordance with the ducting for optimised efficiency. -- Rigid fan installation for reduced start-up noise (Carrier patent) ■■ Physical features -- Flying Bird IV fans controlled by a variable-frequency controller to provide up to 240 Pa available pressure (depending on the size) at nominal flow rate -- Flow control in accordance with the ducting for optimised efficiency with the possibility to program a maximum supply air flow. -- Supply air duct connection frame. -- Suction air connection frame standard for sizes 30RQSY 039-078 -- Suction air filters optional (30RQSY 039-078 only) -- Small unit footprint with a low height (1371 mm) for easy installation in most buildings -- The unit is enclosed by easily removable panels, covering all components (except air heat exchanger and fans). ■■ Integrated hydronic module (option) -- Centrifugal low or high-pressure water pump (as required), based on the pressure loss of the hydronic installation. C A R R I E R 2 0 1 6 / 2 0 1 7 485 CONTROLS Quiet operation AIR TREATMENT Features and advantages