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Evaluation of energy efficiency

Calculation method

Simulation calculations are carried out in two steps. In the first step, the indicators defining the comfort of the building or the requirements of the building (eg air flow, internal air temperature, etc.) are defined. Where the conditions are met, the building's thermal balance is calculated.

For example, when evaluating ventilation systems, the simulation of ventilation air flows is carried out in the CONTAM 2.4 program (description of the program http://www.bfrl.nist.gov/IAQanalysis/CONTAM/index.htm) in a multi-zone model (one room corresponds to one zone) and after determined that the rated system is able to meet the minimum requirements in PN-83 / B-03430 / Az3: 2000 and in technical conditions the calculated air streams are input data for the thermal balance calculations. Calculation of the heat balance is performed in accordance with EN-ISO 13790 (Energy performance of buildings - Calculation of energy use for space heating and cooling), modified by the hourly method 6R1C, in a single zone system (the building is one zone).

Energy efficiency categories NAPE

Based on the results of the simulation, the division into energy efficiency categories of NAPE follows the following guidelines:

  • Energy consumption for a reference building is a reference level of 100% - reference level for primary energy consumption
  • The result of building energy consumption excluding consumption related to the particular component (e.g. lack of ventilation system, lack of hot water preparation, infinite thickness of insulation material, etc.) represents 0% reference level.
  • A score of 0% to 30% inclusive means energy efficiency category NAPE - A1
  • A score of 30% to 50% inclusive means the energy efficiency category NAPE - A2
  • A score of 50% to 70% inclusive means the energy efficiency category NAPE - B1
  • A score of between 70% and 90% inclusive means the energy efficiency category NAPE - B2
  • A score of between 90% and 110% inclusive means the energy efficiency category NAPE – C
  • A score of more than 110% indicates the NAPE - D energy efficiency category

Sample energy efficiency scorecard:

Energy efficiency assessment results are a scorecard and a file containing detailed information on the functioning of the system in the reference building, which is sent directly to the company requesting the evaluation.