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A day in the life of an inefficient gas boiler

admin — Thu, 07 Jul 2022 10:42:26 +0000

Data from one home on a cold winter’s day in January shows how and why inefficient gas boilers end up costing residents more.

Guru Heat Smart allows property managers to monitor and remotely control individual gas boilers or heat pumps. It also captures ambient temperature and humidity data to help predict the risk of mould growth.

The Guru Heat Smart device captures detailed performance data from the heating system, including return temperatures from radiators.

Here we share time series data captured, and insight gained, from just one home.

Data shows that the heating system is working inefficiently

The above graph shows flow temperature (temperature of water travelling from the boiler to the radiators) and return temperature (the temperature of water travelling from the radiators back to the boiler).

The data shows us that return temperatures are almost as high as the flow temperatures, and in some cases there is no difference between the two. In practical terms this means that very hot water is rushing around the heating systems only imparting a small amount of useful heat to the dwelling via the radiators on each loop.

As a result of these high return temperatures, the condensing boiler cannot condense. In this situation the resident is likely to be paying up to 15% too much to achieve the same level of comfort in their home. This cost difference may be enough to push households into fuel poverty. It also means unnecessary carbon emissions.

Using Ofgem’s April 2022 price cap data, on average, paying 15% too much means an extra £155 for this resident on their gas bill per year. The price cap is expected to rise again by 78% in October, turning this £155 into £276.

Why high return temperatures cost residents more

High return temperatures mean boilers cannot work at maximum efficiency.

These two graphs show how efficient a domestic boiler can be at different return temperatures. The graph on the left shows a standard boiler, and the graph on the right shows an older boiler. The data we’re receiving shows return temperatures of up to 80°C and suggests that the boiler in this home is performing at something like 76% efficiency. Looking at the graph for the older boiler, the efficiency of a well performing but older condensing boiler should be more like 88%.

Efficiency curve when the boiler is new	Efficiency curve when the boiler is degraded

Source: Real-time monitoring energy efficiency and performance degradation of condensing boilers, by Simone Baldi et al. (2017)

The boiler cannot reach the temperature desired by the resident

The resident has their thermostat set to 30°C, but temperatures are only reaching 22°C inside the dwelling.

Setpoint temperature

Ambient temperature

This information is especially useful to a resident liaison team. If the heat system was fulfilling the resident’s apparent desire, this home would be being heated to 30°C three times per day. Data like this can help guide conversations around fuel bills.

Data used to indicate risk of condensation and mould growth

One the day in question, relative humidity within the home is, for the most part, low. Should this change, property managers could use this information to improve resident wellbeing with proactive maintenance, reducing property repair costs.

Relative humidity

The data being captured can be used to help understand how well a property is insulated

When heat load data is combined with ambient temperature data, and even outside temperature data, it’s possible to gather valuable information about the thermal characteristics of the dwelling – such as how well it’s insulated. This data can then be used to understand exactly how well a dwelling is performing in real life, instead of taking the EPC rating at face value.

The data being captured can be used help choose the correct heat pump in any future retrofit scenario

We can see that over the recent period of cold weather (including 1°C outdoor temperature) the home has had a peak heat load of 5 kW. This data can be used to help plan for any eventual replacement of gas boilers, including sizing heat pumps.

Central Heating Current Power (Instantaneous Demand)

Conclusion

Capturing detailed performance data from the heating system, including return temperatures from radiators, helps property to identify and resolve performance issues, and reduce maintenance callouts.

By viewing a resident’s heating settings remotely, Guru Heat Smart also helps property managers to spot issues like underheating, and so better support vulnerable customers.

Finally, where heat pumps have not yet been installed, performance data from the existing gas boiler and radiators can be used to correctly size the new system. Data-led insights into building characteristics can also help to guide future decisions around insulation.

To find out how monitoring and remotely control individual gas boilers or heat pumps could help your residents, please contact our Sales team via sales@gurusystems.com or 020 8050 4305

The post A day in the life of an inefficient gas boiler appeared first on Guru Systems.

How to improve gas boiler performance to help protect residents from gas price rises

Georgina Orso — Thu, 31 Mar 2022 11:06:44 +0000

The price of gas is the most obvious driver of energy bills, but one driver that is often overlooked is boiler efficiency. Inefficient boilers can cost residents over £500 more per year.

On paper, boilers perform at around 90-91% efficiency, but field trials repeatedly show that performance in the home is often much worse. A 2009 trial by the Energy Saving Trust found that boilers perform on average at only 82.5% efficiency, with some boilers performing as low as 68.6% efficiency.

Guru Systems monitors gas boilers using Guru Heat Smart, and we’ve seen the same results. Boilers that are expected to perform at around 90% efficiency often only reach efficiencies in the low 70s.

Inefficient boilers cost residents

The price cap which protects customers who heat their homes using gas boilers had already risen by 12% in October, and will rise again by an unprecedented 54% from April.

It’s possible to see the impact of boiler inefficiency on prepayment customers by comparing the price to heat a home at different efficiency levels.

To demonstrate the impact of inefficiency on price, we’ve used Ofgem’s figure of £983 for the average annual gas bill and assumed that the boiler is older (see graphs below), so only performing at 88% efficiency. The cost of energy then rises as efficiency decreases because gas is wasted to achieve the same level of comfort in the home. This is a hypothetical scenario, but the impact on annual bills is clear – a boiler working at 75% efficiency is £171 more expensive to run than a boiler working at 88% efficiency.

Boiler efficiency	Spending on gas to reach the same level of comfort in the home*
88%	£983
85%	£1,018
80%	£1,081
75%	£1,154

Act before the next heating season

While many local authorities and housing associations are beginning to plan to replace gas boilers with heat pumps, the cost and carbon savings associated with this change won’t be realised in time for the next heating season.

To protect residents from price rises (as well as reducing carbon emissions), the aim must be to ensure that gas boilers perform as well as they can until they are replaced.

With proper monitoring and subsequent interventions, gas boilers can perform better ahead of next year’s heating season – something that will disproportionately benefit the poorest households.

Boiler inefficiency is often caused by high return temperatures

Boilers cannot condense when the temperature flowing back from the radiators to the boiler is too high. This can happen when radiators aren’t balanced, or when the thermostat or boiler settings aren’t at the right level – problems that are often easy to solve.

These two graphs show how efficient a domestic boiler can be at different return temperatures. The graph on the left shows a standard boiler, and the graph on the right shows an older boiler.

Efficiency curve when the boiler is new	Efficiency curve when the boiler is degraded

Source: Real-time monitoring energy efficiency and performance degradation of condensing boilers, by Simone Baldi et al. (2017)

You can’t manage what you don’t measure

Most local authorities and housing associations don’t yet have visibility or control over their boiler fleet – this is why we created Guru Heat Smart.

Guru Heat Smart allows property managers to monitor and remotely control individual gas boilers (or heat pumps). The accompanying software displays performance data, ambient temperature and humidity data to help predict the risk of mould growth.

The Guru Heat Smart device captures detailed performance data from the heating system, including return temperatures from radiators, to help identify and resolve performance issues, and reduce maintenance callouts.

Here’s an example of what gas boiler performance looks like on the Guru Heat Smart web platform:

Data from this boiler shows that the difference between the flow temperature (orange) and return temperature (yellow) is almost non-existent. In practical terms this low Delta T means that very hot water is rushing around the heating systems only imparting a small amount of useful heat to the dwelling via the radiators on each loop.

It also shows that the boiler regularly receives water with return temperatures of over 70°C. When water returns from radiators to the boiler this hot, the boiler can’t condense properly. In this situation the resident is paying too much for their heat to achieve the same level of comfort in their home.

This cost difference may be enough to push households into fuel poverty, especially when prices are high. It also means unnecessary carbon emissions.

Data-led interventions

Performance data means that problems can be identified, and the appropriate interventions can be made. There a number of interventions that could be made ahead of the next heating season, including:

Installation of flow limiting Thermostatic Radiator Valves (TRVs)
Reducing the flow temperature of the boiler, especially outside of peak heating season
Rebalancing radiators using existing radiator valves to reduce return temperatures
Improve boiler, cylinder or heating pipework insulation
Improving radiator sizing
Make sure replacement boilers are appropriately sized

Data on how a resident is heating (or not heating) their home may also be useful for resident liaison teams. Data may help guide conversations around fuel bills or fuel poverty.

Underheating and mould growth

Not only are high fuel bills difficult for many residents, but when a house is cold and poorly ventilated, the risk of mould growth is much higher.

Guru Heat Smart captures ambient temperature and humidity data to help predict the risk of mould growth. This information, when viewed alongside boiler performance, can help local authorities and housing associations to support vulnerable customers in a more holistic way.

Better performing boilers use less fuel..

.. and less fuel means lower resident fuel bills.

If you’re interested in learning more about how to improve gas boiler performance, please contact our Sales team via sales@gurusystems.com or 020 8050 4305.

The post How to improve gas boiler performance to help protect residents from gas price rises appeared first on Guru Systems.

Capturing data is the only way to address damp and mould

Georgina Orso — Tue, 11 Jan 2022 09:46:50 +0000

Damp and mould are serious problems. In 2018-19, the most recent data published by the UK government, 27% of households in England reported having an issue with damp – that’s 6.2 million homes.

Damp and mould isn’t a new problem, but more recently the spotlight is rightly being shone on property managers who consistently fail to take it seriously. In October 2021 the Housing Ombudsman published their latest ‘Spotlight’ report on the issue. It said that social landlords should adopt a zero-tolerance approach to damp and mould.

Health impacts

Damp and mould increase morbidity and mortality for a number of health conditions. The Housing Ombudsman recognised this in their report, stating:

Residents living in homes with damp and mould may be more likely to have respiratory problems, allergies, asthma, and other conditions that impact on their immune system. This, set against the context of the COVID-19 pandemic, highlights the potential seriousness of this issue for residents. There are also other broader impacts on the mental health, education and career prospects of residents living with damp and mould, highlighting why there is a real urgency for change.

For many, the only option for ventilation is opening windows, but when coupled with cold spells over winter, damp and mould have a serious impact on the health, wellbeing and comfort of residents.

You can’t manage what you don’t measure

While damp and mould is tricky to tackle once it’s taken hold, prevention is increasingly possible with regular and accurate data capture. Indicators such as humidity and temperature can be monitored over time and used to predict mould growth.

In it’s report, the Housing Ombudsman has urged the sector to change from a reactive to proactive culture when it comes to addressing damp and mould. It recommends a “data driven, risk-based approach” saying that this “will reduce over reliance on residents to report issues, help landlords identify hidden issues and support landlords to anticipate and prioritise interventions before a complaint or disrepair claim is made.”

Data capture to predict mould growth

Capturing data and providing analytics to make it useful is what Guru Systems does. Until recently, we’ve worked mostly with heat networks, capturing and analysing the data that the housing associations, local authorities and private developers need to ensure their networks run efficiently.

We’re now taking the same approach in existing properties that are heated by either gas boilers or air source heat pumps. Damp and mould is more likely to affect these older properties, and data capture is limited.

Introducing Guru Heat Smart

Guru Heat Smart is currently in pilot. We’re working with a large housing association to monitor the conditions that lead to mould growth over the 2020/21 heating season.

There are other benefits too. The Guru Heat Smart device also captures detailed performance data helping property managers to assess the efficiency of each individual boiler across a site. The web platform displays data from the heating circuit, including return temperatures from radiators. With this, problems can be spotted immediately, including whether the boiler is condensing properly.

Damp and mould problems are prolific, but data capture has the potential to stop them in their tracks. Products like Guru Heat Smart mean that housing associations and local authorities can ensure that their tenants benefit from the same smart home innovation that is becoming widespread in the private sector.

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