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NOx Emissions

Pol 2: NOx Emissions

Credits Available: 3 (No mandatory elements)

Credits are awarded based on the NOx­ emissions from space heating and hot water system operation, are detailed in the table below.

Nox emissions criteria table

Taken from The Code for Sustainable Homes, Poll2, page 182

Open flue heating systems or hot water systems cannot be awarded credits.

Evidence Required

Schedule of evidence required

Taken from The Code for Sustainable Homes, Poll2, page 183

Calculation Procedures

It is important to adhere to the relevant calculation procedures in order to assess the NOx emissions and receive credits. There are four calculation procedures:

  • Conversion Factors
  • Excess Oxygen Correction
  • Calculating the average NOx emissions for dwellings with more than one heating/hot water system
  • Calculation method for Combined Heat and Power (CHP) Systems

The following tables can also be used:

Table Cat 6.1: Calculation of average NOx emissions - assessed under Section A of SAP

Table Cat 6.1: Calculation of average NOx emissions for a dwelling - assessed under Section B of SAP

In order to gain credits here, details of primary and any secondary heating systems and flue types must be supplied along with manufacturer's literature confirming dry NOx levels and or boiler class. These items must be presented to the Code Assessor for approval.

Biomass systems are unlikely to meet NOx emission requirements as they typically produce high NOx levels. Their usage should not be overlooked as they may also score well under the energy section of the Code, as they are recognised as low carbon systems and reduce the depletion of fossil fuels.