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Contents 1 - Introduction ..................................................................................................................................... 3 The Daikin VRV Systems Plugin....................................................................................................... 3 2 - System Types ................................................................................................................................. 4 2 Pipe Heat Pump Systems .........................................
1 - Introduction Introduction The Daikin VRV System Plugin The Daikin VRV System Plugin is capable of sizing and simulation of the Daikin’s VRV equipment. VRV (Variable Refrigerant Volume) systems are a frequently used renewable air source solution for heating and cooling. VRV is a modular system with very high efficiencies obtainable with considered application.
2 - System Types System Types 2 Pipe Heat Pump Systems Heat pump systems are able to either cool or heat (but not simultaneously) and are generally used in open plan areas or buildings where simultaneous heating and cooling demands do not exist. 3 Pipe Heat Pump Systems Heat recovery systems can heat and cool simultaneously. These highly efficient systems recover heat (by cooling a space) and moving this energy to area(s) that require heating, for example.
2 - System Types In order for the module to be used within the VE, training on its use should be undertaken by the relevant users in order to assure an adequate level of understanding of the design of VRV systems. On completion of this training the plugin will be provided for use by the trainees. This training can be provided by Daikin as an IES Authorised Training Partner for the VRV module for the Virtual Environment.
3 - Creating a Daikin VRV System Creating a Daikin VRV System The Daikin VRV Systems module is a component of ApacheSim. Once the plugin has been installed, an additional button appears at the bottom of the screen where the Loads, Dynamic Simulation and Batch Simulation buttons appear. Before entering the module either one or more VRV systems should be created as Apache Systems. The number of systems to be created depends on the total building load.
3 - Creating a Daikin VRV System On entering the Daikin VRV System tool you are presented with the following screen. Loads & Autosizing Menu A) Loads and Sizing Tab – This screen enables load calculation for the model, by changing the options within the screen you can define the different types of VRV systems that will be automatically selected based on the calculated loads. B) Selects the VRV system type i. 2 pipe – Heating OR cooling system ii.
3 - Creating a Daikin VRV System b. 3 pipe options (all three phase electrical supply) i. High COP system – Highest efficiency 3 pipe system – larger outdoor footprint – 16 to 24 HP ii. High Temperature Domestic Hot Water system – System capable of providing high temperature DHW as well as heating and cooling via fan coils – 8 to 16 HP iii.
3 - Creating a Daikin VRV System b. The “Peak sum of the fan coil loads” sizes the condenser based on the assumption that all the fan coils will at some point in time demand full capacity which adds in a safety factor over and above the “Oversize system” setting. Please note that an oversized system will cause a reduction in efficiency. G) Loads. This option lets you select between CIBSE or ASHRAE loads calculations H) Fan coil unit type. This button allows the selection of the fan coil unit type.
3 - Creating a Daikin VRV System The number of fan coils selected follows in the next column, if you require a larger number of fan coils then double clicking in this field will allow you to overtype the selection with the required number and the VRV module will re-select the required sized units. Fan Speed denotes the selected fan speed of the indoor unit. Lower fan speeds give increased protection against draughts but offer lower capacity.
3 - Creating a Daikin VRV System The module will then calculate the shortest possible distance to all of the other fan coils and add 30% as a rough guide to pipe distances, the fan coils are all assumed to be in the middle of the room or zone. These pipe lengths serve as an estimation for early stage design but should be corrected to the correct lengths for more accurate results, which is why the pipe lengths themselves are editable. Double click in any of the fields to change pipework lengths.
3 - Creating a Daikin VRV System As system diversity can now be accurately assessed you may find that systems are selected with a high level of diversity (the ability to attach more fan coil capacity than the total capacity available from the condenser) We strongly recommend that any notifications or warnings on your selection are discussed with Daikin who can be contacted on engineering@daikin.co.uk who will be happy to provide confirmation of limitations and help with selections.
3 - Creating a Daikin VRV System D) Simulation Results setting – select or overtype the name of the simulation results file, multiple simulation files can be used for comparison purposes E) Simulate On Site Performance – On pressing this button simulation will begin, the simulation itself comprises of three parts, an Apache simulation, a data gathering period where the module collects data from the simulation file, and finally the calculation of the whole system power inputs which are represented by a progr
3 - Creating a Daikin VRV System Simulation Results It is possible to obtain efficiencies in excess of the published figures with this module, very high or low efficiencies are also possible but can be symptomatic of Apache system or profile anomalies.
3 - Creating a Daikin VRV System Opportunities for heat recovery can be further explored by recovering waste heat and using it in areas where heat is required. Two examples of this are explained in the next section where the inclusion of producing high temperature domestic hot water and also using air curtains attached to the Daikin VRV system can significantly increase the efficiency of the building services within your model.
3 - Creating a Daikin VRV System Ensure that the relevant VRV system is assigned to the DHW demand in the tabular room data and is reflected in the thermal template for the room usage profile The most accurate simulation comes from specifying a single period whereby the entire storage capacity is heated.
