Unfortunately, the air volume and therefore duct sizes required for effective cooling is much higher than the requirement for effective ventilation. This makes it very difficult to achieve noticeable differences in air temperature using a cooling system combined with the MVHR.
A separate whole house air conditioning system or individual room air conditioning units are the most effective way to achieve summer cooling.
Whilst the system is in operation there is very little risk of any cross-talk through the duct system. This is due to the direction of air movement making it difficult for sound to travel through the duct. Rega have over 30 years experience with MVHR systems and have never had cross-talk issues with the systems.
The average annual running cost of a system comes in at around £30-40. Overall the system will save money annually with the reduction on heating bills achieved by controlling the air change rate in the property and effective heat recovery to maintain the air temperature.
The systems are designed to be almost silent in normal operation. During boost operation there may be audible noise at the vents in the rooms or close to the location of the main unit but boost operation will typically only be required whilst showers or baths are in use.
No, the MVHR system will fulfil all the ventilation requirements and meet building regulations.
We recommend the use of a recirculating cooker hood extractor fan in conjunction with the MVHR system. This allows the MVHR to remove moisture and stale air in accordance with building regulations, while the recirculating cooker hood will remove any cooking smells using a charcoal filter without losing the heat.
It is still possible to have a traditional cooker hood extractor, but it is important to consider this will cause significant heat losses whilst the extractor is in use. If this option is taken it is advised to fit the exhaust duct with an air tight motorised damper to prevent additional heat loss.
In terms of performance and resistance the systems are very similar and the duct sizes are specified at a design stage to ensure minimal pressure drop.
The main benefit of a branched system is a lower cost, particularly if there is a loft space available for the duct routes. A radial system utilises smaller ducts for use in areas with a limited void, or for use in open web joists smaller than 254mm.
All our MVHR units are manufactured in our factory in Biggleswade, Bedfordshire. We also manufacture our own duct.
We offer a range of options and extras including different internal and external vents, summer bypass option and a pollen filter. To see the full range please see our data sheet.
There is no performance difference between the wall and loft mounted units. The choice comes down to access and space. A wall unit mounted in a cupboard will be more accessible for annual maintenance, whereas a loft unit can be kept completely out of the living space of the house.
Any basement without opening windows will need additional ventilation to cover what is referred to in the building regulations as a ‘purge’ ventilation rate. The purge ventilation rate is four air changes per hour and depending on the size of the basement we will provide this by using an additional fan unit to provide purge ventilation.
No. The system is set up in accordance with building regulations to meet the ventilation rates of the house whilst by running at a constant, ‘trickle’ ventilation rate. Unlike bathroom extract fans which will run for short periods at a ‘purge’ ventilation rate.
The internal extract air valves are fitted with filters to prevent dust entering the duct system. These filters will require cleaning once every 2-3 months. The main unit will require inspection and filter cleaning once a year. For further information on the maintenance of the system please see our data sheet.
To clean the filters, simply remove them from the air valves or the unit and clean them by running them under warm water and rubbing to remove dust. They can be reinstalled into the system while still wet and will be dried by the air flow.
If the unit is fitted with an F7 grade pollen filter it will need to be replaced every six months.
The Rega MVHR system is fitted with a control switch providing two functions. Summer/Winter control of the fans allows the supply fan to be switched off, running the system as extract only. This is useful if the preference is to have open windows during the summer, as it will half the running cost of the system whilst allowing air to enter the property directly from outside.
The Boost/Normal switch will manually increase the air flow of the system to its maximum. This will provide a faster means of removing stale air when required.
If your system is fitted with a summer bypass unit, it will operate fully automatically to ensure the system is only using the heat exchanger when necessary.
By reading the temperature of the air being extracted from the house; and the internal temperature, the system will open a motorised valve to allow heat exchanger bypass.
For more information on the various modes of operation please see our data sheet.
All our systems are fitted with maintenance free fans, with sealed for life bearings. The fans last an average of 10-15 years without any maintenance requirements.
First fix installation of the MVHR needs to begin as soon as the property is water tight, preferably before the other trades begin. Due to the larger size of the duct used by the MVHR system it is often difficult to route pipes after cable or plumbing pipe has been installed.
Second fix can begin as soon as the ceilings and walls have been plastered and the surfaces are ready for the mounting of internal air valves. Preferably this will be done at a stage when doors are fitted and electricity is available so the commissioning can be completed at the same time.
The units range from 30.2kgs for the 250R to 32kgs for the 600R.
The electrician will need to provide a power supply; which can be a minimum 5A fused spur or a socket, along with a low voltage cable running from the location of the unit to the desired location of the control switch. The control switch will require a single gang 35mm deep back box.
The plumber will need to provide provision for a condensate drain. The unit is supplied with a 1m length of 15mm flexible tube, which we normally recommend plumbing in to a 20mm in-line trap.
The duration of installation will vary based on the size of the property and duct system used, but the average installation time is around 2-3 days for first fix and 1 day for second fix/commissioning.
Due to the size of the duct systems and having to get a vent into every room in the house, a retrofit is normally only possible in the process of a complete refurbishment. There are exception to this in the case of bungalows or similar properties where the whole house can be accessed from the loft space.
If you are looking for us to carry out the installation we will offer a free of charge site survey. If you wish to self-install there may be a charge associated with this. We will always produce a provisional design from drawings before carrying out a site survey.
The installation of the system can be carried out by any competent person and we will issue a full installation manual with a system we supply. However, the commissioning of the system will need to be completed by a qualified person to provide the completion certificate to building control.
We offer different duct systems design to suit a wide range of different void sizes or construction options. The standard duct is circular from 110mm to 170mm outer diameter, but we also offer a selection of rectangular duct as low as 30mm deep where space may be restricted.
If you notify us of any restrictions in space, we can produce a recommended design using the information provided.
Any duct that passes through a fire break will need to be fitted with a fire damper. In the case of a fire break at the ceiling plaster board, we have air valves with fire protection which can be installed.