Case Study

AirEx Smart Airbrick Impact Validation

Performance measurements were used to demonstrate that a new product, the AirEx Floorvent smart airbrick, delivers energy performance improvements in real houses. The measurements demonstrated an average 20% improvement in floor U-values which, when combined with lower air leakage, delivers an overall average reduction of whole building heat loss (HTC) of 12%.

AirEx Floorvent smart airbrick compared to passive airbrick
The AirEx Floorvent smart airbrick only opens when sub-floor ventilation is required to reduce heat loss

The Product

The AirEx Floorvent smart airbrick works by only opening and providing ventilation when sub-floor humidity is high and ventilation is required. The rest of the time the airbrick is closed, reducing heat loss by increasing the temperature of the sub-floor space and increasing the airtightness of the building overall.

The Project

Working together with Elmhurst Energy Consultancy, BTS supported AirEx and EDF Energy to deliver this major monitoring project to demonstrate that the airbrick delivered real benefits in-situ. The project was delivered under the Energy Company Obligation (ECO) Demonstration Action scheme, becoming the UK’s 1st fully completed Demonstration Action project.

A field trial was carried out across 115 homes, using BTS tools Elmhurst supported AirEx to carry out:

The Outcomes

The study found that the AirEx Floorvent smart airbrick significantly reduced heat loss, with an average 20% improvement in floor U-values and 12% reduction in whole building heat loss (HTC). Delivered over a single winter, the project provides a powerful demonstration of the insights that can be delivered by performance measurement in occupied homes.


Dr Richard Jack

Dr Richard Jack

Technical Director

AirEx Floorvent case study statistics

Facts and statistics about this case study:

SmartHTC measurements
U-value measurements
Reduction in heat loss

Building performance measurement made simple.

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SmartHTC on an In Home Display with temperature sensors

SmartHTC Heat Loss API

Unique algorithm and software that calculates an accurate and reliable measurement of whole building fabric heat loss (also known as a Heat Transfer Coefficient or HTC).

Learn more about SmartHTC Heat Loss API
ISO 9869 U-value measurement system

ISO 9869 U-value Measurement System

System for measuring in-situ U-values of walls, floor and ceilings according to the ISO 9869 methodology.

Learn more about ISO 9869 U-value Measurement System