Saving Energy with MVHR
Managing Director of Rega, Chris Hamilton, talks about how MVHR can help to reduce energy consumption and heating costs.
As technology develops people are constantly finding new ways of increasing the air tightness and insulation levels of their properties in a bid to reduce heating bills and overall power consumption of their homes. This increased air tightness and lack of natural leakage creates a necessity to ventilate the property and remove stale polluted air while bringing in fresh air from outside. This is not only important to prevent condensation issues and mould growth, but also to maintain a fresh and healthy home environment.
There is a selection of ventilation systems available to achieve this. The most commonly used is trickle vents fitted into windows and doors to allow fresh air into the property while using extraction fans in the bathrooms and wet areas to extract the stale, moist air from these areas. The drawback to this type of system is that the trickle vents are providing fresh air directly from outside, which during the winter months will be colder and will require more work from the heating system to get back up to temperature, as well as creating draughts throughout the property. Another downside is that the volume of air moving through the trickle vents will be variable based on external conditions such as wind levels which can cause under or over ventilation.
An alternative to this is to fit the property with a mechanical ventilation system with heat recovery - or MVHR. This system is comprised of a central ventilation unit which will be ducted to extract air from all wet areas in the property, bringing the warm extracted air back to the main unit where the heat will be transferred into fresh incoming air being drawn in from outside. Once the fresh air has retrieved the heat from the stale air it is supplied to the living areas and bedrooms within the home. The stale air is then exhausted to outside. The systems are typically between 80 and 90% efficient at recovering heat, meaning if the external temperature is 10 degrees and the internal temperature is 20 degrees the fresh air being bought into the property will be entering at around 18-19 degrees which will help to reduce the load on the heating system. In addition to this, the system can be balanced to achieve the exact required ventilation rates which removes the risk of over ventilation created by variations in wind levels.
Another advantage is that having a single fan unit controlling the ventilation; as opposed to individual bathroom extractors, is that the unit can be located away from living areas reducing noise levels of the system. Unlike extract fans the MVHR system operates continuously at a reduced ventilation rate which again will reduce air movement noise at vents into rooms. The overall result of this is a quiet, controlled ventilation system that will replace stale air in the house with fresh air from outside whilst maintaining as much heat as possible.