The reasons for poor performance of MVHR systems are many a varied but can be summed up by: Lack of proper design, design involves both pressure loss calculation and sound attenuation, higher pressure on a system means more noise so pressure must be low. The design not being brought forward to tender for the M & E installer. The installer not understanding the design and substituting products. The site management failing to sequence first fix properly. Then last but not least the commissioning engineer not understanding the process to commission to low pressure.

Though it is not always possible to cure a system that is already installed it is always possible to understand where the problems lie and often possible to make things better. Sometimes the mayor issue is in fact the way the the system has been commissioned though this is not usual. By systematically using accurate measurement techniques of pressure and flow, and along with inspections cameras to locate specific problems, I can usually arrive at a plan for remedial action that will achieve great improvement.1