IEA-SHC Task25 Design tool

In the framework of IEA Solar Heating and Cooling Task 25 activities, a new software is currently developed /6/. The aim was to produce a user-friendly tool, which would allow the user to design a system without extensive software training.

The simulation program calculates the hourly energy demand of the solar-assisted air­conditioning sub-systems. The calculations are performed on an hourly basis and are summed up to calculate the annual energy demand.

The outputs of the software include the following: electrical energy demand for fans, pumps and compressors; energy demand of the (thermal) back-up system; water consumption. The annual total costs of the system are calculated based on the annual energy demand of the components and their investment, maintenance and capital costs.

The building loads can be calculated or imported if evaluated through building simulation programs like e. g. TRNSYS, EnergyPlus, ESP-r.

Several solar assisted air-conditioning technological solutions can be simulated using this tool. Numerous types of solar collectors are available in a selection diagram that already includes all the necessary coefficient/performance settings and a minimum storage capacity calculation routine. The user can define the collector area and orientation. In general, the routines dealing with the solar energy supply allows a detailed calculation of the performance capability of the plant.

The refrigeration module enables calculation of the following types of cold water production: Vapour compression machine, absorption system, adsorption system, free cooling by means of cooling tower, use of well water. Calculations can be made for air-based systems as well as for combined water-air systems. Depending on the selected systems (with/without air handling unit, with/without chiller), the conditioned space can be supplied with mechanical ventilation or infiltration only, and chilled ceiling or fan-coil systems are possible for sensible cooling.

The design tool will be available for free for the first year after publication in summer 2004.