The user can change the roof, wall and glazing constructions using predefine construction assemblies. The U-value of the different choices are provided in SI units. It is assumed that the floor of the building is adiabatic, i.e. there is no heat flow between the building and the ground.
Exposed thermal mass
The use can specify the amount of active thermal mass within the space. The exposed thermal mass corresponds to a 40mm thick concrete layer with a volumetric heat capacity of 2016kJ/m3 K.
The infiltration rate in Air Change per Hour (ACH) corresponds to volume of fresh air that enters the space through accidentals leaks in the building envelope.
Peak internal gain
These two input parameters set the peak gains from equipment and electric lighting for the space. The time of day schedules for a typical weekday are shown below.
The entry field specifies whether natural ventilation is supported or not. In the latter case, it is assumed that the windows are sealed (no operable). If the windows are operable, ClimaPlus uses the empirical formulas to predict the air exchange rate when the windows are opened. In the case of fan assisted outdoor air supply, it is assumed that an electric fan supplies outside air to the space at a rate of up to 5 ACH. For both options, the windows are opened if all of the following conditions are met: T_outside is between 18°C and 26°C, and T_inside > 20°C.
In order to convert heating and cooling loads into energy use, ClimaPlus support a series of systems using constant coefficients of performance. Gas-fired boiler heating – COP 0.85, electric baseboard heating – COP 1, direct expansion cooling – COP 3, ground source heat pump – COP 3.93.
Carbon emissions from gas and electricity used for heating, cooling, lighting and equipment are calculated using the emission factors given in kgCO2e/kWh. Representative emission factors for some cities are given in the dropdown. And the ‘custom’ entry field allows to enter new values.
Operation energy costs for gas and electricity are calculated using the cost of energy per kWh selected from the dropdown. Custom cost factors can be specified using the ‘custom’ option.