Technical Focus
16Pages

THE NEW WAY TO PROVIDE COMFORT IN 4 PIPES SYSTEMS APPLICATIONS COMFORT SOLUTIONS The use of the Aermec VCF_X4 valve allows to carry out 4-pipe systems with tradi onal fan coil units, ed with a single coil, providing an average energy saving of up to 30% (depending on the applica on), as well as a signicant reduc on in the cost of installa on and materials required. This document presents the energy saving and economic advantages available with the use of the VCF_X4 valve specically designed by Aermec for 4-pipe fan coil unit systems. These innova ve 3-way valves are proposed as an alterna ve solu on to the double tradi onal 3-way valves normally installed in 4-pipe systems with terminal units equipped with double coils. Through VCF_X4 valve considerable energy savings can be obtained, thank to the only one coil use for hea ng and cooling purposes. The best benet of this solu on takes place, especially in the winter, where is available of a larger heat exchanger area, rather than the usual secondary 1 row coil. In this way the system is simplied and the installa on requirements are reduced, as well as signicantly improving the overall system eciency. This allows the energy sources, par cularly heat pumps, to operate with the highest seasonal energy eciency levels reducing consequently the primary energy consump on, as well as an improvement in the system performance of the building-installa on. Technical Sales Support Department

The “Technical Focus” series is intended to oer an example for informa on only of the possible advantages in the use of innova ve Aermec solu ons. As the data and results presented in the publica on refer to specic buildings and situa ons, then these can vary signicantly depending on the applica ons and intended use. For these reasons the calcula ons and considera ons made in this document cannot be considered an alterna ve to the design by a professional engineer. Aermec reserves the right to carry out at any moment any modica ons deemed necessary for the improvement of the product with...

Chapter 1 INTRODUCTION WHY SELECT A 4 PIPE SYSTEM. Main reasons to choose a 4-pipe system: • Service sector buildings growth headed towards architectural solu ons with large glazed areas and lightweight walls, characterised by a low thermal iner a. • An increased demand in the exibility of the use of space that creates a random component when dening loads. • Performance exibility and simplied plant: the possibility of extending the number of terminal units and hence the capacity of the installaon. In modern buildings for commercial sector, the systems using fan coil units with fresh air...

Chapter 2 VCF_X4: THE AERMEC SOLUTION FOR 4 PIPE SYSTEM The tradi onal terminal unit used for 4-pipe solu ons is the fan coil unit with double coil. This is supplied with a main larger coil (3 rows) for connec on to the chilled water circuit, and a smaller coil (1 row) which is connected to the hot water circuit. Each coil has a 3-way or 2-way valve to control the water ow rate. The opening of the valve is controlled by the thermostat and regulates the output capacity, in hea ng or cooling, to balance the demands of the space being condi oned. VCF_X4L: Valve kit for le hand fan coil unit...

“Daily Express” Head Oce London [UK] Aermec: Reference Book Chapter 3 THE VCF_X4 APPLICATION VALVE IN 4 PIPE SYSTEMS FOR GLAZED OFFICE BUILDINGS The system considered consists of a typical installa on for 4-pipe fan coil units and fresh air supply plant serving an externally glazed oce building. To provide a complete overview the energy analysis has been made with the same type of design (building/system), simulated in three dierent European loca ons: • Stockholm (clima c zone Colder) • London (clima c zone Average) • Rome (clima c zone Warmer) The three reference loca ons allow us to...

Intermediate oor, conned on two sides by other air condi oned oces Top oor, conned on two sides by other air condioned oces Intermediate oor, conned on one side by other air condi oned oces West West South-West Congura on and loca on of oce spaces for the building analysed. Es ma on of hea ng and cooling loads for each space To oer a complete overview of the dierent clima c condi ons the loads have been analysed for three representa ve clima c loca ons, as previously illustrated. The oce analysed is an externally glazed building for oce use, located in these three clima c zone, and is used...

WITHVCF X4 VALVE USED As a function of the peak loads in these offices the size of terminal unit (4-pipe fan coil units) are selected, based on three considered technical a) FCX fan coil unit with 3 row chilled water coil and 1 row hot water coil and one VCF valve for each coil. b) FCX fan coil unit with single 3 row coil and VCF_X4 valve. c) FCX fan coil unit with single 4 row coil and VCF_X4 valve. For the locations mentioned has been selected the size of fan coil unit to meet the peak heating and cooling load, at medium fan speed and double coils at 7°C/12°C chilled water, 45°C / 40°C...

This case gives the opportunity to reduce the feeding hea ng water temperature, compa ble with a generated hea ng capacity to meet the load, for the single 3 row coil, and par cularly for the single 4 row coil. In the la er case it is also possible to raise the chilled water temperature, with considera on for the total and latent cooling loads. Par cularly for the choice of the 4 row coil, the larger heat exchanger area ensures a comfortable supply air temperature in hea ng mode, even with par cularly low water temperatures (35°C); the supply air temperatures exceeds 30°C for all unit sizes...

ESTIMATION OF INCREASING ENERGY EFFICIENCY FOR THE MULTIPURPOSE UNIT, MODEL NRP 0700 A4, COOLING MODE, WITH THE USE OF THE VCF_X4 VALVE THAT ALLOWS AN INCREASE IN SUPPLY WATER TEMPERATURE FROM 7°C TO 9°C. 5 COOLING OPERATION Eciency varia ons in cooling opera on for the mul purpose heat pump unit, model NRP 0700 A4, with change of external air temperature and leaving water setpoint. 3,5 T mandata acqua 7°C Outlet water temperature 7°C T mandata acqua 9°C Outlet water temperature 9°C Note: In the example given a mul purpose 4-pipe unit, model NRP 0700 A4 has been used. Cooling output 160 kW...