Why is a calculation method using BINs not an option?

The “bin method” refers to a procedure where monthly weather data are sorted into discrete groups of weather conditions (bins). Each bin contains the number of hours of occurrence of a particular range of weather condition, during an average month or year. For instance the outdoor air temperature.

The energy performance of a specific element of the building or system is calculated for each bin and the weighted sum for all bins is an estimate of the performance over the total period. See more explanation in the link below.

The bin method is kept only as a tool in (other) EPB standards to calculate specific generation devices like heat pumps and cogeneration units in the context of a monthly calculation method.

An hourly method (already included in the set of EPB standards) is much more flexible to calculate heating or cooling needs and to describe the interaction with and between the various technical systems, for instance because each system has a different time schedule.

Another important limitation of the bin method is that there is no ‘memory’ between the bins. In case of energy storage systems or in case of heat accumulation in building elements, a bin does not know how much heat was accumulated or released during the previous time interval, because the bins are not sequential in time in contrast with the calculation using a sequence of (e.g. hourly) time intervals.

This limitation is the reason why a bin method is not an option for the calculation of the energy needs for heating and cooling in a building: the heat accumulation in the building mass typically stretches over several days.