Olympic Construction does not sell ventilation units/systems using the Internet or mail orders as other companies do. The reason for this is quite clear: as BPEC-qualified domestic ventilation installers, we know every property and situation within a property will be different - no two families live the same. Thousands of consumers have expensive uncalibrated equipment installed by unqualified contractors, which do not address the real cause of the dampness and mould affecting the property. One standard thing is that we all produce moisture, so following a detailed inspection of your property, which will include testing any installed systems, our qualified surveyors will provide you with a written report detailing the issues and a cure. Many forms of ventilation systems are available and can also be very effective in certain situations.
Indoor mechanical ventilation falls into four main categories:
- Background ventilation and intermittent extraction fans.
- Passive stack ventilation.
- Continuous mechanical ventilation.
- Continuous mechanical supply and extract heat recovery.
System 1 - Intermittent extract fans
This is the typical type of extraction fan most people are familiar with. They are turned on and off by the user, sometimes via a switch or infrared detector, and they need to operate at a high airflow rate due to the short period of use. As a result, they tend to be quite noisy and less efficient, as they only extract when in use. If it’s daylight, people don’t need to turn the light on, so the fan doesn’t operate.
The advanced System 1 fans we install are ultra-quiet and economical to run. They have a place in modern homes, though we tend to favour System 3 continuous extraction in many cases as these are more effective, allow lower fan speeds, and are much quieter.
System 2 - Passive stack ventilation
This is typically installed in flats and works by using the natural effect of wind speed differences to move air per Bernoulli's principle - the faster air moves, the lower its pressure. Generally, outdoor air, higher up from the ground, is less obstructed, so it moves faster than the air at ground level and has a lower pressure, sucking fresh air through the building. A building's surroundings and design can significantly affect this strategy by causing more or less obstruction, and adequate background ventilation is essential. Simply shutting a door will severely reduce the ventilation effect of this system.
System 3 – Continuous extract fans
These come in decentralised and centralised forms. They are ‘on’ all the time, though at a low-speed setting, which offers excellent 24/7 air changes.
As they run continuously, they are set to run at lower speeds, so they are much quieter whilst being practical. An example is an intermittent fan from System 1, installed in a kitchen away from the cooker, which is required to remove a minimum of 60 litres of air per second. A continuous-running System 3 fan can be set at 13 litres of air per second and still be as, if not more, effective.
Our adaptable, whisper-quiet extract fans are guaranteed for five years. A centralised extract system in the loft is a great option where multi-room extract is required.
They also have a boost function that can be automatically or manually switched for when a need occurs, such as when cooking or showering. System 3 ventilation acts almost like a fireplace will have done when installed with effective background ventilation, allowing air to escape from the property all the time, but in a controlled way. The home stays fresh and airy without the draft or heat loss associated with a solid fuel fire.
System 4 – Continuous extract ventilation, with heat recovery
These systems are more costly to install, as there is twice as much ducting, and the units are more expensive. However, much of the cost is recovered in saved energy, which would otherwise be wasted.
They also supply filtered air rather than air being drawn into homes via windows and trickle vents, so there are significant benefits where asthma or hay fever sufferers are concerned.
How it works
Moisture-loaded air is extracted from a kitchen or bathroom, and replacement air is drawn into the mechanical ventilation heat recovery unit (MVHR) from outside, which will be cooler in winter. It is then passed through an advanced heat exchange unit (most of the heat drawn out of the house is recovered at this point) and pre-heats the dry filtered air, delivered into the habitable rooms within the property. When installed and calibrated correctly, this system provides an economical and environmentally friendly method of effectively ventilating your home.
Other ventilations systems available subject to the problems, construction detail and budget:
Whole house ventilation systems
Due to our training, following an inspection, we can supply, install and commission many practical, innovative ventilation systems, including Nuaire Eco Positive Input Ventilation (PIV) systems. Nuaire were the inventors of the PIV system and have advanced this effective method of ventilation with several high-quality units, and; as far as we know, Nuaire are the only manufacturer offering a 7-year guarantee on their ventilation units.
Moisture-loaded air is extracted from a kitchen or bathroom. Replacement air is drawn into the mechanical ventilation heat recovery unit (MVHR) from outside, which will be cooler in winter, and is then passed through an advanced heat exchange unit. Most of the heat being drawn out of the house is recovered at this point and pre-heats the dry filtered air being delivered into the habitable rooms within the property when installed and calibrated correctly. This system provides an economical and environmentally friendly method of effectively ventilating your home.
PIV and how it works, pushing fresh air in and poor air out
Following our inspection, we match the correct unit to the property's size, layout and occupancy to achieve the recommended number of air changes per hour (ACH)as detailed in Table 1.1b of Approved document F.
Nuaire's whole-house ventilation units supply pre-filtered air to remove pollen and other particulates through the installed filter, with the air customarily drawn from the loft space. The air can be preheated. However, this is rarely needed as, on average, the air in a loft space is a few degrees higher than the air outside, due to the solar effect of the sun absorbed by the roof structure, and heat rising from the habitable areas of the property below. The air enters the property via a specially designed diffuser installed within the ceiling, generally located on the landing, as this is central to the property.
PIVs have limitations. There is no 100% guarantee to cure condensation-related issues, as some companies will have you believe. (Normally, companies sell them to you directly via the internet, without ever inspecting your home.) The trust is they may not totally cure condensation in your home but will reduce the risk, as we all still produce moisture vapour by breathing. The PIV units should be used with your heating system - in properties that are incorrectly heated or not heated, they can sometimes worsen matters.
Single room heat recovery systems (SRVHR).
In some cases, the issues may only be limited to one area of the property, such as an outrigger or attic bedroom. The alternate flow single-room extract unit with a heat retention model can be very effective in this situation. This ventilation unit acts like a combined PIV and an extract system in one room. Air is extracted through the wall-mounted ventilation unit for a pre-defined period of 70 seconds, and then the unit stops and works in reverse, drawing air into the room through the same duct.
Installed within the duct is a highly efficient ceramic heat exchange module, the heat from the exhausted air which passed through the module is retained and is transferred to the incoming dry air. Other less efficient systems are available, which use twin ducts placed side-by-side or one-above-another with two fans. They consume more power, are less energy efficient, and present a risk of the air short-circuiting due to the proximity of the inlet and exhaust ports.
Our single-room ventilator with heat recovery mode is a revolution in indoor air quality
The building regulations Part F require that any equipment capable of being adjusted to variable performance be commissioned correctly by a suitably qualified person (BPEC Qualified). We’ve included this process in our ventilation installations, which cannot be provided by a company selling ventilation over the Internet. Commissioning means visiting and surveying your home correctly, recommending the right system, installing the equipment correctly, adjusting and checking it’s performing as designed when completed, and ensuring the end-user has the documentation and instructions to use it and where to obtain maintenance information and advice if required.
a minimum of 15L/PS, this can be reduced to 8L/ps when a continuous extract unit is installed, with boost facility.
The building regulations Part F require that any equipment which is capable of being adjusted to variable performance must be ‘commissioned’ correctly, by a suitably qualified person (Bpec Qualified). This is a process which we’ve included in our ventilation installations, which cannot be provided by a company selling ventilation over the internet, commissioning means visiting and surveying your home correctly, recommending the right system, installing the equipment correctly, adjusting and checking it’s performing as designed when completed, finally, ensuring the end user has the documentation, instructions to use and where to obtain maintenance information and advice, if required.