Experimental Studies of a Pulse Pressurisation Technique for Measuring Building Airtightness

Xiaofeng Zheng,Edward Cooper,Christopher Wood,Saffa Riffat,David Tetlow,Mark Gillott,Yingqing Zu

doi:10.5334/fce.66

Abstract

A pulse pressurisation technique is developed and utilised for determining building leakage at low pressure, based on a “quasi-steady pulse” concept. The underlying principle of the technique is to subject the building envelope to a known volume change in a short period of time (typically 1.5 s). The resulting pressure pulse is recorded, from which the leakage characteristic at low pressure is determined. The technique minimizes the effects of wind and buoyancy forces and has proven to be repeatable. It can use a compact and portable test rig and does not need to penetrate the building envelope. Therefore, it can obtain the leakage of a building very quickly and efficiently. Throughout the various stages of research and development of the pulse technique, experimental investigations have been carried out under different configurations and scenarios in order to validate the changes that have been made for the purpose of system development and optimisation. This paper provides an overview of experimental investigations in the validation process by covering comparison between blower door and pulse unit, comparison between piston-based pulse unit and nozzle-based pulse unit, testing with multiple pulse units in a large building, testing with a known opening, and testing in different building types with a range of volumes and airtightness levels. It enables us to understand the strengths and the limits of the pulse technique, from the experimental and practical perspectives. A good repeatability level (within ±5%) has been maintained throughout the various developmental stages and the average value of Q50/Q4 reported herein was in close agreement (

Highlights

As concerns related to carbon emission and climate change grow gradually, there has been increased focus on the energy use in the buildings
It has been widely acknowledged that building air leakage is a great contributor to building energy loss in regions where heating and cooling is required and it is important to measure it in the process of new construction and retrofitting in order to achieve good building energy efficiency, durability and indoor environment
This paper provides a succinct overview of experimental validations testing throughout some of the key developmental stages of the pulse technique over the last 15 years

Summary

Introduction

As concerns related to carbon emission and climate change grow gradually, there has been increased focus on the energy use in the buildings. Known as blower door technique, has been well established and widely accepted as a means for measuring building airtightness It comes with its own shortcomings, which have been discussed in scientific studies and practical uses (Cooper 2014, Cooper 2016, ZCH 2014, Okuyama 2012), mainly including: change of building envelope, demand of skilful training to the operative, unrealistic high measuring pressure and coarse interpretation of background pressure during testing especially under windy condition. Experimental setup and test arrangement Various versions of Pulse prototypes were used in the experimental studies, and the schematic diagrams of compressed air driven piston unit (stage 2) and nozzle unit (stage 3, 4 and 5) are illustrated in Figures 6 and 7, respectively For the former, the electronic controller operates the solenoid valve by allowing it to be open for 1.5 seconds. Repeatability During the course of research and development of the pulse technique, various changes in the system components and operations have occurred, such as the replace-

Stage 2 and stage 3 The meeting room in the green rectangle in Figure 5c

Findings

Conclusions