Calculating energy efficiency

Energy is always conserved - it is never lost. However, energy can leave a certain area, resulting in energy losses for this specific area.

Consequently, energy balances can only be prepared for restricted spatial areas with clearly defined boundaries. These boundaries are called the envelope.

In the case of heating or cooling, the area of interest is the “heated or cooled space” or more precisely: it includes all areas in a building in which comfortable thermal conditions should prevail. It is usually convenient to include all “passively heated” areas in the balance, if the balance envelope is simplified in this way. Generally, the choice of the balance envelope is seen primarily in pragmatic terms: for a building it is particularly convenient to opt for the balance limit on the outside of the thermally insulated external building components.

Read more about the principles of energy balances.

The Passive House Planning Package (PHPP) is an important tool for designing Passive Houses consisting of a spreadsheet workbook and a manual. The latest revised edition of the 2007 version has been available since spring 2010.

The Passive House Planning Package (PHPP) provides everything needed to design a properly functioning Passive House including tools for:

• calculating energy balances (including U-value calculation)
• planning the windows
• designing the comfort ventilation system
• determining the heating load
• estimating the summer comfort
• design the heating and hot water supply

It also provides a variety of other useful tools for the reliable designing of Passive Houses as well as:

• verification for Passive House funding (e.g. for low-interest loans available in many countries)
• a simplified verification method (based on the German Energy Saving Ordinance)
• a detailed handbook that provides not only a detailed explanation of the PHPP calculation method but also important details for the construction of Passive Houses – the Passive House construction manual par excellence.
  

Read more about the Passive House Planning Package (PHPP)

Dynamic simulation of a building's thermal performance