Page 1


natural ventilation technical submission

0844 809 2509 | |

Introduction to Airtherm Airtherm Engineering Limited supply a wide range of natural ventilation and lighting systems that can be designed and installed to suit virtually any application. We provide for the commercial, educational, industrial and private sectors and our products are increasingly popular in schools, hospitals, offices and industrial buildings.

natural ventilation technical submission

Natural Ventilation and Lighting systems make use of nature's own power source to provide interior spaces with a fresh air supply or natural daylight illumination or both. Buildings utilising natural ventilation or lighting systems, by their very nature, experience a significant reduction in traditional energy running costs. The Airtherm ‘Wind-iVent’ is a natural ventilation system operating on established aerodynamic principles. As air flows around the terminal itself, positive and negative pressure areas are generated. On the positive side air enters the louvres of the terminal and is directed down through the internal vanes into the room below. The negative pressure on the leeward side of the terminal, induces air to leave the louvres, and stale air from the room below rises and is expelled from the terminal. This process is aided by stack effect, i.e. as cool air enters the windward side of the unit it descends into the room below, and the warm stale air rises in the ducts facing the leeward side providing a naturally fresh environment.

Natural Ventilation| Introduction

Our Natural Product Range Energy Efficient Heating, Cooling, Ventilation & Renewables from Airtherm Engineering Ltd Âť Airtherm Engineering Ltd only use products of the highest quality and experienced engineers with excellence in their field. We aim to provide specifiers and contractors with complete confidence in our service by managing projects closely, adhering to strict safety guidelines, demanding the highest quality workmanship and will continue to strengthen our business by listening to customer feedback.

natural ventilation technical submission

Health Benefits By its very nature, the Wind-iVent (natural ventilator), Solar-iVent, (solar-ventilator) PassiveiVent (passive ventilator) Lite-iVent (combined wind & light ventilator) and our X-iVent (cross wall ventilation) systems all offer a natural solution to health problems commonly associated with mechanical air conditioning units. Rather than re-circulating stale air (and possibly germs), the natural ventilation system is continually removing stale air and replacing it with a fresh supply. The system takes air from the roof level eliminating a proportion of pollution, including hazardous carbon monoxide from roadside traffic that is a common issue with low level ventilation methods.

Suitable Applications Our natural ventilation products are suitable for many applications including schools, offices and hospitals. They are also used in private, local authority and commercial premises including gymnasiums, colleges, universities, reception areas, store rooms, changing rooms, libraries, meeting halls and are also suitable for specialist applications. They provide an ideal solution for delivering a 'fresh' air supply to areas where conventional room ventilation is difficult due to critical noise issues.

The Ideal Solution Our natural ventilation systems offer architects and consulting engineers not only a natural and environmentally-friendly solution but an acoustically efficient, economical and aesthetic answer to ventilation needs.

Natural Ventilation| Product Range

Our Sectors Industrial Our flue and chimney exhaust systems are the obvious products utilised by the industrial sector, however our line of natural ventilation and lighting systems are proving increasingly popular solutions in industrial buildings and factories throughout the UK. Our kitchen canopy system sizes are suited to industrial applications as well.

natural ventilation technical submission Leisure Our natural ventilation and light systems are ideally suited to the leisure sector where a fresh air supply is essential or bright illumination of large spaces is required. Our flue and chimney systems are also ideal to handle any exhaust requirements demanded by the large boilers often used in leisure centres. Popular applications include gymnasiums, sports halls and health clubs.

Healthcare Natural ventilation and lighting is a very popular solution in the health care sector in hospitals, nursing homes and other institutions. Providing fresh, breathable air and natural light for patients and health care workers has numerous benefits to health, recovery and staff productivity. Similarly, our kitchen canopies offer a safe, hygienic working environment where food can be prepared quickly and efficiently without the worry of external contamination.

Natural Ventilation| Our Sectors

Our Sectors Commercial Our complete product range is ideally suited to applications throughout the commercial sector. Increasingly, office buildings are benefitting from new, greener, more efficient technologies such as natural ventilation, natural lighting, heat pumps, solar pv and our energy-saving air conditioning units. Our range of exhaust products, from flues and chimneys to kitchen extract canopies, are also suitable for commercial installation.

natural ventilation technical submission

Educational Our product range is perfect for the educational sector. We have found schools and colleges are often keen to utilise the latest green and eco technology, not just to lower costs but to act as a living experiment for pupils and parents to experience. Our natural ventilation systems are a great solution for classrooms and the daylight supply from our natural lighting products are ideally suited for the daily periods of occupation. The growing use of heat pumps and solar pv technology to generate hot water and electricity while reducing a buildings carbon footprint are also widely employed as part of a whole building strategy. Our flue and chimney exhaust systems are also suited to the buildings heating demands and kitchen canopies can be installed where on-site cooking or food preparation facilities are used.

Retail Our efficient, high performance kitchen canopies are ideal for restaurants and food based retail outlets where food must be prepared quickly, hygienically and safely. They are used throughout the industry by outlets ranging from the small to large. Our air conditioning units are, traditionally, widely used throughout the retail sector. Our growing range of greener, more efficient and Arated energy products are a stylish complement to any shop or as a replacement for older, less efficient models.

Natural Ventilation| Our Sectors

Wind-iVent - Natural Ventilation Systems Our natural ventilation solutions consist of two synchronizing devices: a roof-mounted natural ventilation turret and a wall-mounted unit. Louvres within these units divert external fresh air into the internal spaces creating a stack effect which in turn removes stale air or CO² from the space. Airflow, temperature and CO² within the system are monitored and controlled via pre-set sensors within a given space. The Airtherm “Wind-iVent” is a natural ventilation system operating on established aerodynamic principles. As external wind flows around the terminal itself, positive and negative pressure areas are generated. On the positive side air enters the louvres of the terminal and is directed down through the internal vanes into the room below. The negative pressure on the leeward side of the terminal, induces air to leave the louvres, and stale air from the room below rises and is expelled from the terminal. This process is aided by stack effect, i.e. as cool air enters the windward side of the unit it descends into the room below, and the warm stale air rises in the ducts facing the leeward side.

natural ventilation technical submission

The size and type of application is virtually limitless. Additional roof-mounted turrets and wall vents can be added for larger applications and rooms can be individually monitored and controlled as necessary. The features and advantages of such a system include: •A fresh air supply for workers - proven to increase productivity & reduce staff sickness •Naturally ventilated - reduce your energy costs and carbon footprint without the need for mechanical ventilation •Night time purge of stale air - creating a fresh working environment for staff the following

morning •Better control of building temperature and CO² levels •Free cooling

Natural Ventilation| Wind-iVent

Solar-iVent - Natural Ventilation Systems How It Works The Solar-iVent system benefits of a passive stack and an active stack system, similar to our Wind-iVent range, but with the bonus of a free power source. Our Solar-iVent terminal delivers fresh air and discharges unwanted stale air (CO²) from internal spaces, effectively eliminating the need for traditional methods. The system incorporates a solar powered boostfan which provides additional 200l/s, 400l/s or 700l/s of fresh air within the compartment below.

natural ventilation technical submission

The photovoltaic panel collects daylight and convert this to electricity that is regulated via the charge controller which charges the battery pack. The battery is charged whenever there is enough available daylight to do so and even generates power on a dull day. The Solar-iVent range have been designed to supply fresh air 24 hours a day. The low powered fans are set as standard to simply switch on/off at maximum dampers or as an optional feature they can be speed controlled variably in conjunction with the damper


Standard Components

☼ 12v or 24v DC Power Supply. ☼ 40w or 60w solar cell. ☼ DC carbon fibre battery Pack. ☼ Power management module. ☼ Low powered DC fan unit - 200L/s, 400L/s and 700L/s ☼ iVent control systems operate with peripheral (wind, rain, temperature) devices to suit any and temperature application. Natural Ventilation| Solar-iVent

Passive iStack Natural Ventilation Systems The passive stack ventilation systems shall operate on well-established aerodynamic principals. The manual windows at high & mid-level in each space will provide adequate ‘fresh’ input air at a rate that complies with Building Bulletin 101 and CIBSE guidelines and provide no less than 8 L/s per person via means of positive pressure against the face of the building structure. The positive input air is drawn across each area and through the unit by a negative extract pressure at the ‘Pass-iVent’ louvre face at the far side of area. Contaminated Co2 laden stale air is then drawn through the passive stack mounted at roof level.

natural ventilation technical submission

The system should be intelligently controlled via room mounted temperature and Co2 sensors, with occupancy Co2 levels taking presidency over that of temperature.

The passive stack roof ventilation terminals shall be constructed from fully welded corrosion resistant type 1050 AH14 pure aluminium of 2-3mm thickness, and highly resistant to weathering as well as chemical attack. The units will be manufactured in accordance with BS EN ISO 9001, and to suit the architectural and design parameters as indicated in the design specification and drawings. Internal airways are to be protected by incorporating anti-bird mesh to the terminal louvers. The units shall be powder coated to the RAL colour as indicated within the design specification. If required the independent airflow testing & acoustic performance of the roof units from a reputable source such as BRE or BSRIA to show compliance can be issued following order placement.

Natural Ventilation| Passive-iStack

Natural Lighting Solutions Day Lighting systems actively capture daylight from the rooftop and project through a highly reflective tubing to where it’s needed. Solatube light tube system uses the most advanced technologies to ensure that the efficiency and performance of their systems is unrivalled. Extension tubes are available in lengths of 610mm (straight) or 380mm long incorporating a 0-30° adjustable angle along with the new 0-90° angle unit. All reflective tubes – including adjustable tubes – are manufactured from 99.7% reflective Spectralight Infinity material, allowing tube lengths of up to 15 metres for the SolaMaster 330 DS.

The new Solatube 160 DS, 290 DS & 330 DS (250mm , 350mm and 510mm diameter respectively) set performance standards never seen before. These systems feature patented Raybender® 3000 Technology and LightTracker™ Reflector to deliver unprecedented levels of light – higher even than previous Solatube models. Highly efficient and simple to install, the Solatube Brighten Up® Series can transform dark or windowless areas – ideal for residential applications such as kitchens, bathrooms, hallways, stairwells, utility rooms, living areas, or may be installed in multiples in larger, open workspaces such as corridors, offices, consultancy rooms, store rooms, and washrooms.

Natural Ventilation| Lighting Solutions

Natural Lighting Solutions DIFFUSER OPTIONS The Brighten Up® Series offers a choice of diffusers that incorporate Solatube® proprietary lenses for highly effective light distribution. Each features a sleek low-profile dress ring. These attractive and stylish double-glazed diffusers integrate seamlessly into most ceiling surfaces with no visible fasteners. VUSION™ DIFFUSER The Vusion™ diffuser fits neatly to the ceiling and delivers outstanding natural light diffusion through a prismatic lens. OPTIVIEW® DIFFUSERS The technologically advanced OptiView® diffuser uses a multiple Fresnel lens system with a stunning architectural look to deliver crystal clear daylight. Available in three designs. White Trim with OptiView® diffuser Stainless-Tone with OptiView® diffuser Frosted Shade with OptiView® diffuser

Natural Ventilation| Lighting Solutions

Specification Material:

Extruded Aluminium

Construction: Blade mitres fully welded Frame:

None – internal supporting frame

Fixings: or flat

None – base suited to raised cill


Range from 300mm – 6.0m


0.5m to 3m high

Finish: aluminium

Standard – mill finish

natural ventilation technical submission

and option for powder coating

High Capacity - Our natural ventilation terminals are perfect for both natural, passive and solar powered options, with all four sides possessing a guaranteed 50% free area allowing a more efficient operation. High Performance - With the addition of internal vertical channels and integrated water defence, our standard terminals can be converted into high performance Class A rain protection (over 99% effective). Internal & Trunk – Housed inside the terminal is a full height divider which keeps fresh and stale air separate. Both the terminal base and ductwork below are lined using a Class ‘O’ type 12.5mmTHK acoustic foam. The foam offers an ideal acoustic characteristics and the necessary fire performance. Additional acoustic layers can be applied to conform to any design criteria required. The roof lid is also acoustically lined to prevent unwanted noise transfer from heavy rain droplets, which can be amplified into the occupied space below. This method also avoids condensation forming on the underside of the roof with cold air entering the terminal and hot stale air rising from below.

Natural Ventilation| Specification

uPVC volume control dampers Standard features

Options specified

Ultra high shut off Independent tests show no leakage below 10Pa; the pressure most likely to be found in natural ventilation installations.

Belimo /Siemens modulating actuators factory fitted The use of Belimo SM series modulating actuators allows dampers to be set fully open, fully closed or anywhere in between, for maximum adjustability and assurance of comfort.

natural ventilation technical submission

Excellent thermal insulation With a theoretical U value of less that 1 W/m2, uPVC volume control dampers lose.

Ultra high shut off In independent tests, large format uPVC volume control dampers yielded leakage results normally only achieved by dedicated shut off dampers. The VCD sent for testing had a nominal size of 1000mm x 806mm, the large size tantamount to our confidence in the damper.

With even 10Pa rarely being exceeded in natural ventilation situations, it is clear how uPVC volume control dampers can enhance the efficiency of your new natural ventilation system.

Natural Ventilation| Dampers

Actuators The actuator is controlled by means of a standard control signal DC 0 ... 10 V. It opens to the position dictated by this signal. The measuring voltage U allows the damper position (0 ... 100%) to be electrically indicated and serves as a follow-up control signal for other actuators. Manual operation is possible with the self-resetting pushbutton (the gearing latch remains disengaged as long as the pushbutton is pressed).

Belimo 24v 10nm Actuator

Electronic motor driven actuators for three-position and modulating control, nominal torque 5 Nm (GDB), 10 Nm (GLB) or 2 Nm (GSF), mechanically adjustable span between 0...90°, prewired with 0.9 m long connection cables. For damper areas up to 0.8 m (GDB) / 1.5 m (GLB), frictiondependent for GSF‌1 2 up to 0.3 m2 Suitable for use with modulating controllers (DC 0...10 V) or threeposition controllers for air dampers or air throttles.

The modulation of the window free area will be in tandem with that of the ventilator stack for each space via 24vDc chain driven actuators, having quiet operation. The external window openings will operate in conjunction with the same control signal as the damper stack openings, with the exception that the windows will operate at five positions as opposed to the 10 positions of the ventilator actuators to minimise window motor wear and ongoing maintenance of the DC chain driven actuators.

Natural Ventilation| Actuators

Siemens 10nm Actuator

Window Control Actuator

Our Range of Control Solutions Standalone Sensors * Room Temperature and C02 Sensor * Room Temperature and RH Sensor * Room Temperature and RH Sensor with manual override * Standard room Temperature Sensor

Natural Ventilation Controls Our unique range of natural ventilation controls and intelligent sensors have been developed to deliver optimum control and ease of use of all our natural ventilation systems. We can supply traditional combined sensors (with 0/10v outputs) or sensors with inbuilt BACnet communications (which supply a modulating control signal to end devices such as window actuator controllers). Our sensors are specifically designed to be simple to use.

natural ventilation technical submission

Intelligent Sensors * Intelligent BACnet Room Setpoint Unit * Intelligent Temperature and C02 BACnet Sensor * Intelligent Temperature BACnet Sensor with manual override * Intelligent Temperature and C02 level Indicator Standalone Controllers * Temperature and C02 Room Controller * Temperature and C02 Room Controller with manual override * Temperature and C02 Sensor controller with carbon monoxide indicator. * Temperature room Controller with manual override * Temperature room Controller

We employ push button overrides, LED status indications and clear labelling to make things easier for the end users with the temperature control, the room set point for the control of the ventilation dampers can be adjusted in 10C increments between 210C and 280C with a seasonal change over and a night cooling option if a time clock or BMS time signal is available. Localised Heating can also be controlled and is set 20C below the room set point.

Peripherals & Devices * Chain Window Actuator * Combined Weather Sensor * Digital alarm Unit * Digital Extension Timer * Power supply Unit with Time Clock * Window Control Module with Power supply. Temp and CO2 Sensor

Natural Ventilation| i-Controls

Room Temp Sensor

Dynamic Thermal Modelling Natural ventilation modelling We can model complex natural ventilation strategies making due allowance for: • Wind and buoyancy driving pressures • The action of occupancy behaviour regarding ventilation openings • Automatic controls based on temperature or CO2 levels • Night cooling and thermal mass

natural ventilation technical submission

• Wind-iVent and other natural ventilation systems

This type of modelling is far more effective and removes the risk of under performing ventilation systems within the building We can advise on: • The required number and size of ventilation solutions such as terminals, wall ventilation

and windows • The value of night cooling and exposed thermal mass • Appropriate strategies to meet BREEAM comfort criteria

We can offer full dynamic thermal modelling using the market leading software. This software utilises building integrated modelling whereby the same software can be used for multi-faceted studies. Airtherm Engineering Limited can carry out a thermal model of the building to ensure the ventilation conforms to building bulletin 101.

Natural Ventilation| Thermal Modelling

Installation Units can be installed on almost every roof including flat, pitched and even on the roof apex where appropriate. The roof fabric of commercial applications has bearing on the openings and roof plates that are required to install the systems competently. We offer a roof plate solution for all situations, including self mount flashings and curb mount flashings with suitable upstands. The options for each project will be discussed at the design stage in detail, including the necessary openings that are required to suit our systems. The ductwork for the units can pass through any floor level to transfer air within the building. The units are capable of being controlled and linked to the buildings BMS to ensure dampers are fully closed in the event of a fire. ‘Wind-iVent’ units can be controlled via master control panels, room temperature sensors and CO² sensors.

natural ventilation technical submission

We can also offer many bespoke natural ventilation solutions to clients. Our highly skilled work force adapt at all types of light to medium metal fabrication including stainless steel, aluminum and mild steel. GRP moulded products are also available, most suited to circular formation. The most common range starts from 500mm to 1200mm and can be combined with a natural lighting system formally known as the ‘Lite-iVent’ . The Lite-iVent (Light & Vent) system uses both the wind and sun, and offers a ZERO carbon footprint which has no impact on the environment. Our installation engineers are competent in their field and carry all necessary site certification with CSCS cards, IPATH, PASMA and scaffold towers. Our engineers strive towards excellence in each and every project they undertake.

Natural Ventilation| Installation


natural ventilation technical submission WIND-IVENT SYSTEMS





• Penthouse Passive Stack Terminals

This new build school project is the amalgamation of two local Primary Schools John Roan School, & Maze Hill School situated in south east London.

Airtherm Engineering have recently completed the new installation of two natural ventilation systems for Derry Building Services Limited based in Newark.


• uPVC Volume Control Dampers • 32no aqua blue ventilation turrets • Insulated internal diverters • Internal bird screen • Access lockable doors

The design of the school incorporates various environmental features to provide a low carbon solution, including natural ventilation & lighting systems The terminal sizes have been selected by our new computer aided software ‘Wind-iCalc’ and fully conforms to the CIBSE requirements.

Natural Ventilation| Case Studies

Airtherm had previously designed and selected the correct systems to serve the new hall within the School. This process required critical information to establish the correct airflow and terminal size, and working closely with both Derry Building Services and Leicester Council this installation was a success.


natural ventilation technical submission WIND-IVENT SYSTEMS





The Coppice Primary School is a two form entry school ,though larger than the average primary school. Airtherm completed the 1st phase works by installing two ‘Wind-iVent’ Systems to the newly completed single storey class rooms. The 2nd phase fix features a further six 1.2msq units for the Hall area which will be used mostly by the Church, and a further six 1.1msq units serving the Classrooms

The newly built sports centre is based in Perry Barr, Birmingham and will hold high end boxing national events.

Airtherm Engineering have recently completed the new installation of two natural ventilation systems at Midland College Studio. Airtherm were MVS Ltd first choice when considering the scheme due our knowledge and experience on previous installations.

The new installation of fourteen natural ventilation systems for MVS Limited had been designed and carefully selected from the room data sheets provided, ensuring adequate ventilation rates for the pupils are met.

The natural ventilation systems have been designed in line with all current publications such as CIBSE guidelines, AM10 Natural Ventilation in commercial buildings and Building Bulletin 101.


Natural Ventilation| Case Studies

There are six terminals located within the sports hall and one situated within the mezzanine floor area serving the office space. Airtherm also provided the control solution which consists of standalone room temperature and C02 sensors and Red Lion interface panel.

The project involved the use of our Airtherm wall mounted icontrol solution which consists of room mounted ABS plastic control panel C/w inbuilt temperature sensor, C02 self-calibrating carbon dioxide sensor with traffic light indicators, night time cooling and external rain sensors. The complete system was commissioned by our appointed engineers.

natural ventilation technical submission

0844 809 2509 | |

Airtherm natural ventilation brochure 2013  

Our Natural Ventilation & Lighting brochure is an introduction to the various systems we offer, detailing the health benefits, suitable appl...

Airtherm natural ventilation brochure 2013  

Our Natural Ventilation & Lighting brochure is an introduction to the various systems we offer, detailing the health benefits, suitable appl...