Heat Pumps & Electric Boilers for The Portal, North Acton

Project Overview

Modutherm supplied the heating solution for The Portal in North Acton, London — a 36-storey residential development delivering 350 new homes to the long-term rental market. Contractor: O'Shea.

The Development

The Portal is a landmark build-to-rent development on Portal Way in North Acton, West London, designed by HTA Design. The 36-storey tower delivers 350 new homes, including 118 affordable units across London Affordable Rent, London Living Rent, and Discount Market Rent tenures — making a significant contribution to housing provision in the London Borough of Ealing.

Located just 150 metres from North Acton Underground Station (Central line), the development offers excellent connectivity to central London whilst bringing new homes, active ground-floor uses, and public realm to a rapidly regenerating part of West London.

The Challenge

A 36-storey residential tower with 350 apartments requires a heating solution that can deliver substantial, reliable output whilst meeting the increasingly stringent low-carbon requirements for large-scale residential development in London. The system needed to operate entirely without gas — eliminating direct emissions and future exposure to fossil fuel price volatility — whilst providing sufficient resilience for a building of this scale and complexity.

The Solution

Heat Pumps:

• Seven AW290 50kW air source heat pumps in cascade configuration
• 350kW total heat pump output
• Natural R290 refrigerant with GWP of 3
• COP up to 4.4 at standard rating conditions
• A+++ energy efficiency rating
• EVI scroll technology for reliable performance at low ambient temperatures
• BMS-ready controls for integration with building management systems

Electric Boilers:

• Two Genesis Eco 160kW electric boilers
• 320kW supplementary and peak load capacity
• 99.9% efficiency
• Zero direct emissions
• No flue or gas connection required

Key Benefits

• Fossil Fuel Free: The entire system operates without gas — no direct carbon emissions from heating across all 350 apartments
• Scale: Seven AW290 units in cascade deliver 350kW of primary low-carbon heating capacity for a major residential tower
• Resilience: The two Genesis Eco electric boilers provide supplementary output and peak load cover, ensuring reliable heating across all 350 homes
• Efficiency: COP up to 4.4 on the AW290 units significantly reduces energy consumption compared to direct electric heating
• Complementary Technology: Heat pumps and electric boilers work together seamlessly — both fossil fuel free, both BMS-compatible, both zero direct emissions
• Future-Ready: Natural R290 refrigerant and electric-only plant position the building ahead of tightening building regulations and London Plan requirements

Results

The combined AW290 and Genesis Eco installation delivers 670kW of fossil fuel-free heating capacity for one of North Acton's most significant new residential developments. The system's all-electric, zero-direct-emission approach supports compliance with London Plan energy policies whilst providing the output and resilience demanded by a 36-storey building serving 350 homes.

This project demonstrates how large-scale build-to-rent developments can achieve fossil fuel-free heating through intelligent system design — combining high-efficiency heat pumps with electric boilers to deliver reliable, low-carbon comfort at scale.