Attending the meeting of the iSERVcmb project (Inspection of HVAC systems through Continuous Monitoring and Benchmarking, 2011-2014) along with the workshop in Athens brought interesting information about HVAC systems in Europe. The HVAC systems consume up to 11% of total EU use in 2007 and it is necessary to know what kind of action can be taken to reduce the energy in buildings and use legislation power to achieve savings needed in the building sector at the reasonable and practical level.
As the recast EPBD (European Building Performance Directive) will be implemented in 2014, there is a need for clarification of specific requirements for the treatment of HVAC systems in Europe in old and new buildings including nZEB buildings (nearly Zero Energy Buildings) by year 2020. Implementing of nZEB building will require significant lowering of energy in both residential and non-residential or commercial buildings respectively. The non-residential buildings pose a challenge due to the wide variety of activities. The practical approach is to reduce HVAC system energy use to achieve long-term savings.
The extensive study in Cardiff University ´s buildings show the initial savings of 10-15% in gas use when use of the control and attention paid to the systems. Another study HARMONAC shows that the overall energy use is affected by choice of HVAC system including maintenances and inspections. Typically the energy use in HVAC systems is around 30-40% of total electricity energy use.
Ian Knight from the Cardiff University says: “For an HVAC system to work efficiently the interaction between the heating, cooling, humidification and ventilation components are crucial, as are the interactions with the climate, building fabric, design choices and occupancy.”
“It is necessary to have good operation, maintenance and control of an HVAC system including good record-keeping and choice of the correct type and design of system for the end use activity. The key to increased long-term energy efficiency rests with making it cheaper for the owner to run their systems efficiently. There should be an alternative that rewards good energy management by allowing systems to avoid inspection if they achieve certain standards. There is no real understanding in the market of the effect of HVAC system choice and design on the actual energy efficiency achieved in the practise.”
The HARMONAC project identified about 37% of the possibility of energy savings by the more detailed sub-hourly monitoring. This could equal up to 10% of the primary energy used in the buildings. Automatic monitoring gives the necessary continuous feedback on performance of HVAC systems to help to achieve and maintain the savings.
The HARMONAC findings resulted in changes in EPBD with allowing to alternative choice between physical inspections and automatic monitoring. The study also resulted in more emphasis on automatic monitoring and control system in recast EBPD.
Simply conclusion of how it all started lines in the wider usage of continuous monitoring systems to achieve maximum savings including relating of activities in building to be benchmark accordingly and have an impact on HVAC system. Also the HVAC systems which deliver the best energy performance in practise need to be fully documented.