The data-driven modernisation strategy behind decarbonising a Central London office development

The Client

A landmark London office development with ageing HVAC infrastructure had become both an operational risk and a financial liability. Driven by ambitious net-zero targets, the site required a comprehensive, data-led decarbonisation strategy rather than a standard equipment replacement.

To deliver this upgrade in a live business environment, a strategic design and build partnership was formed with Carrier. Carrier was awarded the OEM turnkey contract through a competitive tender process, with its capacity for thorough value engineering proving to be a key differentiator.

The Challenge 

The site’s primary challenge was replacing the deteriorating and unreliable 1998 natural gas boilers, which were fundamentally incompatible with the client’s 2026 target for full building decarbonisation. Transitioning from this legacy combustion system to an Air Source Heat Pump (ASHP) solution required careful planning to overcome technical and logistical hurdles while ensuring full business continuity in the building in active use.

Logistical Constraints:

• Operational Continuity: The building required zero downtime; Carrier managed this via a phased changeover and temporary boiler provisions.
• Urban Logistics: The project required high-precision planning for four separate crane lifts over four months in a restricted Central London location.
• Environmental Sensitivity: New equipment had to meet specific local noise level requirements to protect tenant comfort and ensure regulatory compliance.

From a strategic perspective, the status quo was becoming increasingly difficult to justify economically. The energy model – assuming an operational schedule of 12 hours per day, 20 days per month – applied a 15% deterioration factor to the old units.* This resulted in a system Coefficient of Performance (COP) of just 0.78. When modelled against electrical and gas tariffs of £0.25/kWh and £0.07/kWh respectively, the legacy plant represented a growing cost burden and a notable carbon liability.

The Solution 

• Equipment: Modular 61AQ Solution (2x120P & 2x300P)
• Refrigerant: R290 Natural Refrigerant (Ultra-low GWP <3)
• Operating Temp: 60°/70°C (Direct Boiler Replacement)
• Impact: Eliminated coil replacement (reduced complexity)

Carrier acted as a trusted adviser, moving away from traditional vendor roles to provide a collaborative engineering partnership. This began with a comprehensive data collection phase, using ultrasonic heat meters to log and trend primary Low Temperature Hot Water (LTHW) data over six months. This detailed profiling allowed for a true understanding of the building’s thermal requirements, ensuring the new plant was accurately sized for actual peak loads rather than theoretical design margins.

Carrier’s value-engineered proposal offered a superior technical and environmental alternative.

The selection of the AquaSnap™ 61AQ units using R290 natural refrigerant was central to the value-engineering strategy. By delivering 70°C water, Carrier enabled a direct boiler replacement that used the existing building fabric. This removed the need for costly and disruptive replacements of downstream coils – a requirement of the lower-temperature competitor specification – thereby preserving the client’s CapEx and significantly shortening the project duration.

The turnkey scope included comprehensive system-wide upgrades:

• Digital Connectivity: Connection to the Abound™ HVAC Performance platform, providing continuous remote performance optimisation, proactive maintenance, and long-term asset protection.
• Infrastructure: A full HV/LV transformer upgrade to support the transition to electrified heating.
• Pumping Optimisation: Replacement of all primary and secondary LTHW pumps with high-efficiency Variable Speed Drive (VSD) units.
• AHU Conversion: Converting smaller Air Handling Units (AHUs) to Direct Expansion (DX) solutions with heat recovery (300 kW capacity) via run-around coil systems.

This level of technical accuracy ensured that the project was more than a replacement, representing a complete modernisation of the building’s energy profile.

The Result 

By delivering a fully compliant design and build solution under a single instruction, Carrier provided a streamlined, accountable path to net zero. Central to this success was the integration of the Abound™ HVAC Performance platform, which enables remote monitoring and provides the proof of savings required for modern ESG reporting.

Projected Annual Performance Outcomes:

• Efficiency Gains: A 182% improvement in system performance, raising the COP from 0.78 to 2.21.
• Energy Reduction: Projected savings of 602,090 kWh per annum.
• Carbon Impact: A projected annual reduction of 102,982 kg CO2e.

The qualitative benefits of this turnkey delivery were equally significant. The single-phase delivery model ensured the project was completed on programme and delivered within the agreed budget. By avoiding internal modifications and coil changes, Carrier minimised tenant disruption while maximising ROI.

The partnership has now transitioned into a long-term ongoing support phase, including a comprehensive maintenance contract and continuous performance optimisation via the Abound™ HVAC Performance platform. A strong indication of client satisfaction is the continued trust between the two organisations; following the success, Carrier was awarded a subsequent major decarbonisation project.

This project confirms Carrier’s position as a trusted partner for sustainable, low-carbon heating solutions, capable of delivering measurable results in complex urban environments.

* The Energy Report is based on a standard set of assumptions. An energy model was developed by projecting the building’s average monthly heating demand and correlating it with the part-load performance of equivalent existing equipment, adjusted with a 15% deterioration factor to account for reduced efficiency. The expected energy savings and return on investment were estimated using simulated average values derived through interpolation and engineering assumptions based on the predicted building energy load profile. 

To find out more about how Carrier can support your facility’s HVAC service and maintenance needs, call 01372 220 220 or visit www.carrier.com/commercial/en/uk