Showersave: The Smart, Proven Solution for Low-Carbon Hot Water Efficiency

As the UK approaches the 2025 implementation of the Future Homes Standard (FHS), housebuilders, specifiers, and sustainability leads are facing new challenges in designing homes that meet ambitious energy efficiency and carbon reduction targets. While air source heat pumps (ASHPs) and high-performance building fabric have become the standard for space heating, the efficiency of hot water systems continues to lag behind—creating a growing performance gap.

Hot water is now the largest energy demand in homes built to the Future Homes Standard. Even in well-insulated homes with low space heating needs, we continue to lose valuable energy—and money—down the drain every time someone showers.

At Showersave, we offer a simple, proven, and cost-effective solution: Waste Water Heat Recovery for Showers (WWHRS). This passive technology can reduce hot water demand by up to 50%, improve the efficiency of heat pump systems, and support reliable compliance with the FHS—all with zero user interaction or maintenance requirements.

A Smarter Approach to Hot Water Efficiency
Air source heat pumps are highly effective for space heating in homes with excellent thermal envelopes. However, their efficiency drops significantly when meeting peak hot water demand—particularly in larger or more active households.

The industry’s typical workaround—installing oversized hot water cylinders or adding immersion heater back-up—drives up installation costs, increases energy bills, and introduces complexity. It also undermines carbon reduction targets and occupant satisfaction.

WWHRS addresses these issues at the source. By recovering heat from shower waste water and using it to pre-warm incoming cold mains water, it reduces the energy required to produce hot water in real time—helping heat pumps operate within their optimal performance range and avoiding the need for electric top-ups.

How It Works
WWHRS is a passive, gravity-fed system that uses a vertical heat exchanger to reclaim energy from warm waste water as it drains from the shower. That recovered heat is transferred to the incoming cold water feed, either boosting the temperature of water entering the hot water cylinder or directly feeding the thermostatic mixer shower.

This passive technology has no moving parts, requires no electricity, no servicing, and no user input—making it a robust and future-proof enhancement for domestic hot water systems.

Independently Verified Performance
To validate real-world performance, Showersave commissioned independent laboratory testing in partnership with energy efficiency expert Chris Martin (formerly of the Energy Monitoring Company) and the Centre for Sustainable Technologies at Ulster University.

Key findings included:

More consecutive showers without cold water interruptions. With WWHRS, hot water remained available for longer, improving user experience.
Lower energy bills: Electricity consumption for domestic hot water dropped by 31–36% in standard systems and up to 47% when immersion back-up was active. For a typical four-person household, that equates to an annual saving of £150–£200.
Faster cylinder recovery: Recovery times were halved, enabling smaller cylinder sizing without compromising comfort.
Reduced system stress: Heat pumps operated more efficiently, with fewer peak loads and reduced demand on electrical back-up systems.

A Strategic Advantage for Housebuilders and Designers
WWHRS is not just an energy-saving add-on—it’s a strategic tool that supports compliance, performance, and long-term customer satisfaction. For developers, it offers:

Demonstrable compliance support: WWHRS is included in the notional specification for Option 1 of the Future Homes Standard and is fully recognised in SAP assessments with robust test data.
Low embodied carbon: Certified as a Passive House Component, WWHRS aligns with whole-life carbon assessment and circular economy principles.
Lower build costs: Smaller cylinders and simplified hot water designs reduce both capital and operational expenses.
Higher occupant satisfaction: Reliable hot water availability helps reduce post-occupancy complaints—a key KPI for developers and warranty providers.

Easy Installation, Immediate Impact
WWHRS systems from Showersave are simple to install using standard plumbing techniques. They’re suitable for both new builds and retrofit applications, with no need for specialist training or tools. With no moving parts and zero maintenance, they offer long-term performance without hidden costs.
Whether you’re designing a single dwelling or a multi-unit development, WWHRS is an immediate win:

Why Choose Showersave?
Since bringing WWHRS to the UK market in 2008, Showersave has delivered over 200,000 installations across the UK and Europe. We work closely with developers, M&E consultants, and housing associations to integrate WWHRS into their build specifications, providing:

Technical support and design guidance
BIM-ready product data
Recyclable units with industry-leading lifecycle performance
Design, manufacture and distribute

With the Future Homes Standard just around the corner, now is the time to design hot water systems that meet both the letter and the spirit of energy efficiency legislation.

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Email:

sales@showersave.com