Are Healthy Homes Being Suffocated by Dumb Air?

Dr Pete Armstrong, CEO / CTO and Co-Founder of Mixergy, describes the problem in simple terms. “You might put a lot of measures in to improve the insulation and seal up drafts,” he says. “However, it’s quite easy to create unintended consequences.” 

The unintended consequence is often ventilation. Continuous extract systems are commonly installed to manage humidity and prevent damp and mould. But fixed rate systems create a trade-off. Whilst ventilation protects air quality, it can also remove heated air and increase running costs. In practice, residents may switch systems off if they perceive them to be expensive or noisy. 

In this context, “dumb air” refers to fixed rate, continuous ventilation that does not respond to real time indoor conditions such as occupancy, humidity or CO2 levels. 

From a Healthy Homes Hub perspective, this is a systems issue rather than a component issue. Energy, air quality and affordability cannot be treated separately. If ventilation increases bills, residents may disengage. If systems are complex, the mental load increases. The result can be higher humidity, elevated CO2 levels and greater mould risk.  

Smart air versus fixed ventilation 

The distinction between “smart air” and fixed ventilation is helpful. Fixed ventilation runs continuously at a set rate regardless of occupancy or indoor conditions. Smart ventilation responds to measured data. 

CO2 is one indicator. Outdoor levels sit at roughly 400 parts per million. Above 1,000 parts per million, occupants may feel drowsy. At 1,500 to 2,000 parts per million, research links exposure to reduced cognitive performance. In smaller or overcrowded homes, those levels can be reached quickly. 

Responsive systems can modulate airflow based on CO2, humidity, temperature and other pollutants. If a property is unoccupied and air quality is stable, ventilation can reduce to conserve heat. As occupancy increases and indoor pollutants rise, flow rates adjust accordingly. The objective is to protect health without driving unnecessary energy use. 

For housing providers responding to Awaab’s Law and increased scrutiny of damp and mould, monitoring alone is not sufficient. Data that simply reports poor air quality without enabling intervention leaves landlords exposed. Closing the feedback loop between measurement and control is critical.  

Evidence from St Basil’s 

A pilot with St Basil's explored how coordinated control of heating, hot water and ventilation could support both affordability and air quality. 

The programme combined connected storage heaters, solar integrated hot water cylinders and air quality sensors. The findings were practical. By shifting heating and hot water demand into off peak periods, households achieved overall bill reductions of 20 to 30 per cent. In properties using prepayment meters, that reduction can determine whether supply is maintained. 

At the same time, monitoring identified periods where humidity and temperature created mould risk. Adjusting ventilation settings and providing targeted prompts supported healthier indoor conditions. 

The trial also highlighted behavioural challenges. Residents often set storage heaters conservatively to avoid running out of heat, or fully charge them to prevent discomfort, leading to overheating. Linking controls to weather forecasts reduces this uncertainty and limits waste. 

For Healthy Homes Hub, the principle is clear. Retrofit must extend beyond hardware. Control, data and usability are part of building performance. 

Operational implications for housing providers 

The operational implications are significant and go beyond technology selection. 

First, responsive ventilation and connected heating alter the role of asset management teams. Instead of periodic inspection cycles and reactive repairs, providers can move towards exception based management. Homes that sit within acceptable temperature, humidity and CO2 ranges require less intervention. Resources can then be focused on properties that fall outside safe thresholds. 

Second, data integration becomes a governance issue. Air quality, energy consumption and hot water performance data must sit alongside existing compliance information, including damp and mould reporting, legionella management and fuel poverty indicators. Without clear ownership of that data within the organisation, insights risk being lost between asset, housing management and repairs teams. 

Third, there are implications for repairs and maintenance workflows. If ventilation units are left switched off, or if noise leads to resident disengagement, the issue is not solely technical. It becomes a customer experience and communication challenge. Providers will need clear processes for responding to alerts, triaging risk and recording interventions to demonstrate compliance. 

Fourth, retrofit procurement models may need to evolve. Specifying fabric measures alone is insufficient. Employers’ requirements should set expectations around integrated control, remote visibility and performance reporting. The incremental cost of connectivity is modest compared with overall retrofit investment, yet its operational value can be substantial. 

Finally, resident engagement strategies must reflect varying digital confidence. Some tenants will welcome app based feedback. Others will prefer simple reassurance that systems are working in the background. The objective is not to create more data for residents to manage, but to reduce mental load while protecting health. 

In short, smart air is not a gadget. It is part of a shift from passive buildings to actively managed homes. That requires alignment between asset strategy, housing management, compliance and customer service.  

Practical steps for housing providers 

• Assess ventilation performance alongside insulation upgrades to identify potential heat loss and mould trade offs. 

• Pilot responsive ventilation controls in electrically heated or high density properties. 

• Use real consumption data to review tariff suitability, particularly for prepayment customers. 

• Integrate air quality, heating and hot water data into a single operational view to support early intervention. 

• Ensure systems are simple to use and address noise concerns before large scale deployment. 

Decarbonisation remains essential. However, healthier homes depend on balancing energy performance with air quality and affordability. Without responsive control, airtight homes risk becoming costly, uncomfortable and, in some cases, unsafe. 

Mixergy is inviting social housing providers to express interest in taking part in trials of their Smart Home Energy Management System (SHEM) 

SHEM brings together smart hot water control, indoor air quality monitoring, adaptive ventilation, and a tariff optimisation engine in a single connected system. The goal is to give housing teams real visibility of conditions and energy performance across their stock, reduce the risk of damp and mould, and cut the cost of hot water and heating for residents who are already stretched.

Early results from a pilot with St Basils, running since early 2025 across 32 self-contained apartments, point to energy bill reductions of around £200 per resident per year, a 20% average saving on electricity tariffs, and a reduction in compliance admin time of over 50%. 

The beta is a structured trial programme, and partners will work with the Mixergy team to define measures of success, receive installation support aligned to their scheme type, and feed directly into the product roadmap. It's designed for providers where damp, mould risk, or high electricity costs are live issues, and where there's an appetite to test, learn, and share what works. 

Providers interested in joining the next beta cohort can get in touch via mixergy.co.uk/social-housing-hem  

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