Dalair Limited's Technical Centre

Dalair Limited
Air Handling Equipment

Dalair Limited offers an unrivalled depth of range and expertise in all aspects of the design, manufacture, testing, installation, service and maintenance of our British made air handling equipment. 

Founded in the early 1980s, we manufacture bespoke air handling units (AHU's) to serve office blocks, shopping centres, hospitals, factories, pharmaceutical companies, car manufacturers and the like: including specialised, desiccant dehumidification units for use in archive stores and cold storage facilities for film and pharmaceutical use.

Our AHU's are specifically designed to meet our customer's precise requirements. We believe this approach delivers the most cost-effective and energy-efficient solution.

Our Service and Maintenance division (DSM) offers unrivalled service and maintenance packages. Our dedicated teams of highly skilled service engineers fulfil our customers' requirements for installation, service & maintenance and refurbishment of our own and other manufacturer's equipment.

Large AHU undergoing volumetric test at our Technical Centre

Products & Services

Dalair Limited supply a range of quality air handling equipment, custom-designed and built to suit customer requirements. Moreover, our designs are invariably tailored to optimise efficiency and minimise running costs; resulting in systems that are not only better for the enviroment but are also of benefit to your budget. 
Additional services offered include factory and on site AHU testing, site installation services, routine preventative maintenance contracts and extended warranties. Our service and maintenance division also undertake site surveys and refurbishment of our both our own and other manufacturer's equipment.

Spares, from filter media and drive belts to replacement motors and fans, are also available from our service and maintenance division.

Colourful "Sun Yellow", rooftop AHU's at one of the International Quarter buildings, London

Air Handling Units 

AHU Design

Preliminary design, at tender stage, is undertaken by our technical sales staff and is based upon the required volumes, taking into account any limiting factors or unit specification.

Once an order is placed, the project is passed to our contracts department, where the initial design will be fine-tuned and finalised by our highly experienced contracts engineers.

General arrangement drawings are then produced, using up to date CAD facilities, and are issued for written approval prior to manufacture . 

We are able to provide Revit rfa files of our AHU's for incorporation into your BIM projects.

Units are manufactured in the UK at our Wednesbury head office.

AHU Construction

Although materials may vary with the unit size and application, all AHUs are of a similar construction; namely an outer framework of posts, assembled using knock in corners, into which double skin, insulated enclosure panels are fitted to form a rigid, airtight compartment.

Smaller units can be supplied as a single section, whereas larger units are usually supplied in modular form, split into manageable sections for final assembly (bolting-up) on site.

AHU sections are generally supplied with a sturdy channel base support frame, complete with lifting holes to facilitate craneage.

All internal components, such as the fan and motor assembly, are built in to the unit sections and are provided with access or removable panels, if necessary, to facilitate maintenance and removal.

All forms of component commonly utilised in air handling equipment can be incorporated into the design such as filters, heaters, coolers, humidifiers, attenuators, plate heat exchangers, thermal wheels and run around coil heat recovery systems.

AHU Ranges & Applications

HSF Range

Premier bespoke construction
Robust insulated steel framework
Fully powder coated framework and base support
50 mm double skinned panels
Excellent enhanced thermal and acoustic properties
Internal & external applications
High pressure applications
Air volumes up to 100 m³/s

SPMA & MA Range

Bespoke construction
Aluminium framework
"SPMA" 25 mm double skinned panels 
"MA" 50 mm double skinned panels
Excellent enhanced thermal and acoustic properties
Internal & external applications
High pressure applications
Air volumes up to 60 m³/s

Platinum Range

Plug & play
Rotary or plate heat exchanger 
Integrated BMS controller
Fully factory wired
Universal control functions
High efficiency
Optional components 
Air volumes up to 5.5 m³/s

Specialist Applications

High efficiency 
Saline/coastal applications 
Cold free/thermal break construction 
Hospital equipment
CO4/HTM specifications 
Swimming pool equipment 
Pharmaceutical equipment 
Food industry 
Critically acoustic projects 
Desiccant dehumidification

One of Dalair Limited's most prestigious contracts: - The Shard

(Photo by Fred Moon on Unsplash)


AHU Testing

We can provide both in-house and on-site testing of our air handling equipment at our dedicated, 50,000 sq.ft (4,650 m²), test facility accommodationg all the latest test arrangements; -

     • Leakage (pressure)
     • Volumetric (performance)
     • Acoustic (in duct and casing radiated)
     • Vibration monitoring

In December 2008, Dalair Limited invested in a dedicated test facility, capable of accommodating the test arrangements for the largest size of unit we can manufacture. Prior to this, there had always been conflict, as the factory space required for manufacture would be occupied by large test arrangements. Additionally, acoustic tests could not be performed until after normal working hours, resulting in late nights and overnight stays for our customers witnessing the tests. The acquisition of the Technical Centre and its location, at the end of a quiet cul-de-sac, has alleviated both of these problems.

Installation & Maintenance

Dalair Limited employs dedicated teams of service engineers to fulfil our customers' requirements for installation, service and maintenance of our air handling units.

All operatives are Construction Skills Certification Scheme (CSCS) card holders as proof of their occupational competence and site experience.

The following services are available: -

     • Site assembly of units supplied in flat pack form
     • Final assembly ("bolting up") of units supplied in sections
     • On-site testing of units
     • Investigation and rectification of faults occurring within the warranty period
     • Performing scheduled service and/or maintenance of our AHU's nationwide
     • Carrying out ad-hoc repairs and/or maintenance outside of warranty

We consider that the commissioning of specialised air handling unit components, such as humidifiers or gas heaters, is best carried out by the original equipment manufacturer. We can arrange for the commissioning of these items to be included as part of our offer of supply.

Download our Installation & Maintenance Service Manual (Draft copy October 2022)


If you do not have a credit account with us, spares can be supplied on a pro-forma invoice basis, however, payment must be cleared prior to despatch.

We are also able to accept payment by credit card. All card payments are subject to an additional 5% administration charge.

There is a minimum order value of £100.00.

Our contract reference or the general arrangement drawing number, if known, will help us to identify the correct spares for your installation.

Our spares list includes, but is not limited to, the items listed below: -

     • Replacement filter media
     • Spare Keys                     
     • Door rubber
     • Drive Belts
     • Pulleys and taper locks
     • Anti-vibration mounts
     • Back
     • Door locks and latches
     • Manometers and manometer fluid
     • Motors
     • Fans
     • Replacement coils

Please contact Dalair's Service & Maintenance division for a quotation for spares. 


Our air handling units are supplied with a free standard 12-month warranty, in respect of faulty workmanship and components from the date of delivery and subject to full and documented evidence that maintenance has been carried out by competent engineers or, preferably, Dalair's own service engineers

So far as it is reasonably possible, we will pass on the benefits of any guarantees or free service commitments, offered by the manufacturers or suppliers of items of equipment incorporated into our air handling units.

Dalair do not accept responsibility for repair costs and remedial work to AHU structures or components caused through damage during off-loading, craneage and installation, the lack of or incorrect maintenance, incorrect operation, system dampers closing or failing allowing full fan pressures to be exerted on the unit structure, malicious damage or incorrect wiring/piping of components.

Please refer to our standard Terms & Conditions of Sale for full details of the warranty.

Extended warranties are available.

Condition Reports

Dalair's Service & Maintenance division can undertake site surveys of our own and other manufacturers's air handling equipment and provide you with a detailed, comprehensive condition report that will enable you to decide the correct course of action to take.



Refurbishment of existing equipment, (both of our own and other company's manufacture), can have significant advantages, including : -

Extends the lifespan of existing installations.
Cost savings compared with that of a replacement system.
Reduced downtime and minimal disruption.
Increased efficiency utilising the lastest energy efficient components.


One of Dalair Limited's prestigious contacts: - Bluewater Shopping Centre, Kent 

(Photo by DAVID ILIFF. License: CC-BY-SA 3.0)

Policy Statements

Senior Leadership  Team Vision Statement

The vision we have at Dalair Limited is to strengthen our position as the leading provider of high quality Air Handling Solutions by delivering value and exceeding the expectations of our customers while protecting the environment and ensuring the safety of those involved in our activities.

We aim to preserve at all times our reputation in building upon the quality of our products and the excellence of our people. 

Leadership Principles

Our Leadership approach is to build an attractive and safe place to work whereby the company targets set are achieved by managing business and leading people.

Dalair Limited is a privately owned company that operates nationwide, has a passion for our people and is purely focused on implementing
the following criteria: -


• Gives and encourages active, open and honest communication across all hierarchy levels.
• Uses delegation as a key leadership tool while sharing knowledge and ideas with others. 


• Shows initiative and personal commitment.
• Encourages curiosity, open-mindedness, continuous improvement and learning. 


• Sets an example, acts loyally and consistently.
• Provides a vision, thinks positively and encourages employees to progress. 


• Acts with an entrepreneurial spirit with in-depth expert knowledge.
• Motivates, develops and integrates people. 


• Executes plans, delivers business success and implements change.
• Sets clear priorities and delivers on promises.  


• Understands our people, listens to them, trusts them, cares for them and recognises their success.
• Takes responsibility for own actions and stays balanced under pressure.  

Our Core Values

Our success is derived from creating value for our customers, employees & suppliers alike.

We will continuously improve the product and our service from within our organisation.

People & Environment

• We are committed to an injury-free workplace where everyone goes home safe.
• Respect for people and provide means to care and protect for them in the environment where we operate. 


• We keep our promises and meet our commitments.
• We remain truthful to ensure fairness in all our relationships. 

Customer Orientation

• We are committed to long-term partnerships focused on creating value for our customers.
• Customer satisfaction is achieved through the high quality of our people and their work. 

Cultural Diversity

• We cultivate our attitude through mutual respect with sharing of experiences.
• Diversity is a strength that creates a richness within our organisation. 


• We build our relationships with our customers, employees and suppliers on a foundation of trust and respect.
• Leadership will ensure a good balance between empowerment and control.  

Pride in Our Employees

• We create a future by nurturing an entrepreneurial spirit through out our business rewarding success.
• People are the core of our business and ensure our future success.  

Dalair Limited have supplied AHU's for many of the high rise structures in Canary Wharf 

Management Systems

Since its conception in the early 1980s, Dalair Limited has consistently demonstrated its commitment to quality, the environment and health & safety issues by adopting the relevant management systems and attaining accreditation to recognised industry standards.

Information relating to our company policies and objectives is made freely available to all employees, all actual and potential customers and suppliers and  all external interested parties.

Dalair's Quality, Environmental and Health & Safety policies are displayed in the reception areas and on notice boards at all company locations. Electronic copies are also included within the company's Internet pages.

Standards of Certification

BS EN ISO 9001:2015

Quality Management System

Dalair Limited first achieved certification of its Quality Management System (QMS), to BS 5750, Part 1 standards, in November 1988.

With the introduction of new quality standards our QMS has been upgraded, with certification to BS EN ISO 9001:1994 gained in December 1995, BS EN ISO 9001:2000 in December 2003 and BS EN ISO 9001:2008 in October 2010

Our current QMS, certified to BS EN ISO 9001:2015, was awarded in December 2017 and includes the operations of our London sales office, the Service & Maintenance Department and the Technical Centre.

BS EN ISO 14001:2015

Environmental Management System

Dalair Limited successfully achieved certification of its Environmental Management System (EMS) to BS EN ISO 14001:2004 standards in November 2009. Our current certificate, to BS EN ISO 14001:2015, was awarded in June 2018.

We have taken on the requirements of the ISO 14001 standard to help us minimise the impact our business activities have on the environment.

We hope that by raising environmental awareness throughout the company and by influencing those who work with us, we will create a positive effect upon the environment locally and on a global scale.

BS ISO 45001:2018

Health & Safety Management System

In November 2011 Dalair Limited successfully achieved certification of its Health & Safety management system, to OHSAS 18001:2007 standards. 

Our current Health & Safety certification, to BS ISO 45001:2018, was attained in October 2020.

As a responsible manufacturer, Dalair Limited is committed to best practice in all matters relating to the health, safety and welfare of its employees and those who may be affected by our business activities.

Our aim is to develop a culture whereby the achievement of health and safety objectives will be regarded as an integral part of our business.

We have been members of the British Safety Council since November 2003 and became a certified member of the CHAS scheme in September 2016. 

Management System Manuals


Recyling Instructions for
Air Handling Units

Dismantling & Disposal

Dalair Limited have also supplied AHU's for many of the buildings in the City, including Lloyd's Register, the Gherkin and Walkie Talkie building  

(Photo by © User:Colin and Kim Hansen / Wikimedia Commons, via Wikimedia Commons)

Contact Us

Please do not hesitate to contact us if you have any questions with regard to our products or services.
Furthermore, your feedback, comments and suggestions are always welcome and will assist us in continuously improving our business.
Your name and email address are required, however, if you would prefer us to contact you by telephone, please enter the number and we will get back to you as soon as possible.


Where To Find Us

Dalair operates from four locations, strategically placed to cover the whole of the UK.

The core elements of our business, including our main manufacturing facility, are based at our Wednesbury Head Office.

All AHU tests are carried out at the nearby Technical Centre, which also serves as the base for our Service & Maintenance division.

Whilst satellite sales offices, located in central London and Manchester,  complement our presence in the Midlands and are ideally situated to serve the Southern and Northern regions.

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