Ventilation Systems

Although the installation of ventilation systems appears to be on the increase, it is not always the case that this will improve the SAP rating, in fact often it is the reverse. It is essential that any ventilation system installed has been tested under the Appendix Q system (which can be found on line), to ensure that true values can be used in calculations, rather than the default values. If such a system is required, careful consideration should be given to the power usage of the system in relation to the actual benefit. Heat recovery systems can provide high energy saving by retrieving heat from internal heated air before it is expelled to the outside, but careful consideration should be given to analysing performance prior to installation.  Your SAP Assessor should be able to provide guidance in this matter.

Appendix Q was introduced to promote energy efficient ventilation products that offer benefit in SAP and DER (Dwelling Emission Rate) calculations.  Within the Appendix Q database, which can be viewed on line, individual manufacturers’ product data is stored to replace the normal/default settings for each ventilation option. The ‘default figures’ used in SAP calculation are the lowest acceptable figures for that component of SAP.  Each product is tested to provide a specific fan power performance that can be used to calculate 'energy saving' figures.

The Appendix Q process highlights the market’s most efficient domestic ventilation products, ergo offering recognition for improved performances, values and benefits.  Any product listed has been tested by BRE under a set of similar conditions to produce a fair and accurate assessment of that boiler’s performance.  This allows SAP assessors and Energy consultants to ascertain true energy consumption and cost of an installation. If the system does not appear on Appendix Q, then default SAP values have to be used. This encourages developers and designers to select systems that have been tested to ensure the full and true picture of energy flow is obtained.

• Thermal Properties
• Thermal Mass
• Thermal Bridging
• Cylinders & Measured Heat Loss
• Dimensions
• Boilers & SEDBUK (Seasonal Efficiency Database of Boilers in the UK)
• Ventilation Systems & the Appendix Q database
• Solar Gains
• Insulation
• Space Heating Systems
• Water Heating Systems
• Low Carbon Power Souces
• Condensation & Dewpoint Analysis
• Heat Pumps