Jason our mechanical engineer recently attended a BPEC Domestic Ventilation Systems course, sat the exam and passed with flying colours.  Jason is now qualified under Part F of the building regulations to commission, balance and sign off ventilation systems in domestic applications.  This will be very useful to Gale & Snowden especially when it comes to mechanical ventilation with heat recovery (MVHR) systems in homes.  As a practise we are finding that MVHR systems require particular attention in domestic applications to ensure that they perform as intended and provide good air quality in a noise free manner.   MVHR systems need to be designed and installed correctly taking account the room layout, the air tightness barrier and duct penetrations, noise break out, other plant systems such as wood burners, pressure drop to keep fan power to a minimum and air distribution within the spaces to name but a few elements.   Once this has been covered a well designed and correctly installed system requires to be correctly commissioned and balanced at the end of the construction period if it is to perform as intended in a trouble free manner.

In buildings that are becoming increasingly air tight it is even more important that air quality is maintained otherwise VOCs (volatile organic compounds), gases and chemicals, dust and particulates, moisture and odours can build up in the home which then become detrimental to health and the building.   Whilst it is important to be energy efficient this cannot be at the detriment to air quality.  Gale and Snowden can now design and detail MVHR systems as well as install and commission them.   We can now ensure that all areas of the MVHR design and installation is carried out to the highest standard.     See our low energy mechanical engineering service for further details.  
As well as providing mechanical designs in-house on our own architectural designs we also provide a low energy mechanical design service to other architects throughout the country who are also working on prestigious low energy projects.   Our in-house team have been designing MVHR systems for over 15 years now which include both commercial schemes (offices, hospitals, museums) and domestic schemes.    We have also designed these systems with C02 & humidity controlled variable volume control and a variety of earth duct and ground piped heat exchangers and carried out extensive thermal modelling work looking at the feasibility of earth heat exchangers at keeping buildings cool when moving into future climate change scenarios.  Some of this work can be found here:   
We also intend to offer this service to clients who wish just for a check and verification of MVHR systems being commissioned by others and also for trouble shooting problem systems.    Our in-house team has experience in monitoring and fault finding problem ventilation systems and fine tuning them to operate correctly.   This may involve taking simple air flow measurements and rebalancing to leaving temperature, humidity and C02 sensors within the ductwork and room space to determine how well any system is performing.   We have found that MVHR systems in homes generally require a fine tune typically a year after hand over to ensure they are working to their optimum.  
Temperature & Humidity Logger in Ductwork
The presentation below provides details of an investigation we carried out on the MVHR systems at Knights Place one of our Passivhaus schemes.  We wanted to determine if frost protection was required or not and also investigate in-situ the efficiency of the MVHR system.  A sub meter on the power supply to the MVHR system was installed as well as temperature, humidity and C02 sensors were installed in the rooms and within the ductwork.  This presentation presents a snap shot of some of the analysis and results so far.