Air Handling Unit Refurbishment

Commercial Offices;  St Pancras & Somers Town, London

HALO HVAC case study AHU Refurbishment


Our client is dedicated to achieving net zero and is cutting carbon emissions by removing on-site gas-fired boilers, aligning with sustainability goals, and marking a major shift towards an eco friendly operational model. 


Attention was given to the ventilation system to maintain a comfortable working environment without compromising heating capacity. Balancing sustainability with employee comfort became a focal point, ensuring the revised heating infrastructure met both environmental and operational requirements. 


HALO HVAC adjusted ventilation and heating design based on occupancy levels, adopting new DX heat pump technology for efficient temperature management. The AHU was remodelled to accommodate the new efficiency objectives. 


A shift towards more effective heating and cooling solutions. The HALO HVAC initiative showcased a holistic approach to sustainability, addressing energy efficiency and employee well-being. This not only aligns with environmental standards but also positions the organization as a leader in responsible business practice.


AHU Remodel


The existing AHU layout proved inadequate for accommodating the new components, particularly with restricted access to the fresh air intake section. 


Our engineers undertook a remodelling of the AHU to optimize its layout, ensuring compatibility with the new, more efficient design, new EHB coils, filtration, and framework. This included a redesign of the existing attenuation.



Before and After examples

HALO HVAC AHU Refurbishment - air handling unit refurbishment
HALO HVAC AHU Refurbishment - air handling unit refurbishment
HALO HVAC AHU Refurbishment - air handling unit refurbishment
HALO HVAC AHU Refurbishment - air handling unit refurbishment
HALO HVAC AHU Refurbishment - air handling unit refurbishment
HALO HVAC AHU Refurbishment - air handling unit refurbishment

New Electric Heater Battery (EHB), 
Direct Expansion Coil (DX) 
and Filtration 


The installation of the new electric heater battery and DX heat pump coil represented a pivotal step in enhancing the functionality and efficiency of the existing AHU system. 


These involved adjustments tailored to accommodate the updated design parameters and airflow requirements, ensuring optimal performance and compatibility with the new technology. 


Furthermore, recognizing the importance of air quality in indoor environments, we ensured that the installation was accompanied by the incorporation of new ISO 16890 compliant filters. These state-of-the-art filters are designed to meet rigorous standards for air filtration, enhancing the AHU's ability to maintain clean and healthy indoor air. 


Through our diligent efforts in modifying the AHU casework and implementing advanced filtration technology, we not only successfully integrated the new components but also elevated the overall performance and reliability of the system. This comprehensive approach reflects our commitment to delivering sustainable, high quality solutions that prioritize both functionality and indoor air quality.




HALO HVAC AHU Refurbishment - air handling unit refurbishment

Corrosion Treatment 


The discovery of corrosion on the internal surfaces of the existing AHU presented a critical maintenance challenge that demanded immediate attention. Our technicians commenced the process by carefully sanding down the areas affected by rust, ensuring thorough removal of all corroded material. Following the sanding process, vacuuming equipment was utilized to eliminate any loose debris or contaminants, guaranteeing a clean and debris-free environment within the unit. 


With the AHU's surfaces prepared, our team proceeded to apply a high-quality rust treatment solution. This specialized treatment not only halted the progression of existing corrosion but also provided a protective barrier against future oxidation, safeguarding the AHU's structural integrity over the long term. Where necessary fabrication was performed with new materials. This proactive approach to addressing corrosion not only mitigated immediate concerns but also served to significantly prolong the AHU's operational lifespan.



HALO HVAC AHU Refurbishment - air handling unit refurbishment

Before and After examples

HALO HVAC AHU refurb - air handling unit refurbishment
HALO HVAC AHU refurb - air handling unit refurbishment
HALO HVAC AHU refurb - air handling unit refurbishment
HALO HVAC AHU refurb - air handling unit refurbishment
HALO HVAC AHU Refurbishment - air handling unit refurbishment

An Outstanding project Delivery

HALO HVAC AHU refurb - air handling unit refurbishment


Following weeks of thorough planning by the HALO HVAC Projects team, the seamless execution of mechanical and electrical tasks transpired within a single day. This encompassed the efficient delivery of all new components and the removal of redundant materials. 


Despite the project's expedited timeline, it was executed without any health and safety concerns, ensuring zero downtime and minimal disruption to the client's use of the building. We stand out by expertly coordinating project deliveries, demonstrating unmatched precision and efficiency in the HVAC industry. 


As a testament to our commitment, we provide comprehensive after-sales care for every project we undertake. The client committed to net zero, eliminating gas-fired boilers for carbon reduction. The HVAC system, now based on DX heat pump technology, ensures comfort while meeting sustainability goals. HALO HVAC's holistic approach positions our organization as a leader in responsible business practices



Watch the Case Study Video

Clean Room & Labs, Chandlers Ford 

13 Air Handling Units serving a critical manufacturing process and science laboratories, all requiring refurbishments, controls and BMS modifications, delivered in 5 days, whilst achieving 26t a year CO2e reduction.


5 Star Hotel, Knightsbridge, London

The belt-driven fans in the hotel's air handling units failed, causing no ventilation in critical areas; urgent reinstatement was essential for to ensure the Hotel was fully operational & compliant.


Kettering General Hospital

Bringing the Air Handling Unit in line with compliances such as HTM 03-01 whilst reclaiming lost heat through new ventilation strategies, enabling energy savings.


Food Manufacturer, Rugby

Ventilation is vital for food production, ensuring air quality and contamination prevention. Upgraded filtration and AHU refurbishment guaranteed compliance, reliability and effectiveness.


Offices. Gracechurch Street, London 

With the building owners advertising for new leases a key objective was to ensure the indoor environment is comfortable and healthy. Over time, the existing AHUs became less efficient, leading to higher energy bills and reduced indoor air quality.


5 Star Hotel. Mayfair, London

This luxury hotel operates 24/7 therefore we had to deliver this project with zero disruption. We completed all works in 2 evenings whilst staging the works to allow for ventilation to continue during daytime hours. 


Recent Projects;




Conformity & Compliance

HALO HVAC Ltd has passed industry leading conformity and compliance testing, verification, and inspection. Our accreditations highlight our technical competences, reliability, and integrity to provide confidence and trust to deliver our services.


We hold insurances for Contractors All Risk, Professional Indemnity, Employer Liability, Public and Product Liability, and Contract Works. We are members of Constructionline, Building Engineering Services Association, and The Contractors Health and Safety Schemes in Procurement including PAS91 and SSIP.


Call to request copies on 0207 117 2087 or email


We need your consent to load the translations

We use a third-party service to translate the website content that may collect data about your activity. Please review the details in the privacy policy and accept the service to view the translations.