Atamate against overheating 1: assessing the problem

The Atamate building operating system (atBOS) was designed around the premise that mitigating overheating should be a priority for any building project. Its sensors can collect data to quantify overheating in an existing building and inform renovations as well as for post-occupancy evaluation on a new build or completed renovation.

 

The above video was made by a resident of a London block of flats during a 2021 heatwave in which the indoor temperature reached 44°C (111°F). The building was effectively uninhabitable for much of the day and as heatwaves become more frequent in the coming decades, the problem of overheating will worsen for residents of high-risk areas like London and will affect residents of areas yet to be classified as high-risk.

The Atamate approach to mitigating overheating

At Atamate, we’ve been calling for measures to mitigate overheating to be written into the building regulation for some time. We’re gratified to see that the Department for Levelling Up, Housing and Communities (DLUHC) has now done so by drafting Part O of the UK building regulations which, as we’ve summarised elsewhere, comes into force in June 2022.

The atBOS functions that can be applied to mitigating overheating fall into two broad categories:

Sunrise and Silhouettes by Maria Eklind
Sunrise and Silhouettes (Maria Eklind [CC / Flickr])
  • Data collection: A network of sensors collects detailed data on the building’s indoor environment and service operation. In a renovation project, that data can be used to inform the selection of the most cost-effective approach to mitigating overheating. When the project is complete, it can be used for post-occupancy evaluation to ensure that the mitigation measures are being used appropriately and confirm that the building complies with the Part O requirements.
  • Automation: By taking control of a building’s services, atBOS can ensure that they are used as effectively and efficiently as possible to keep a building’s temperature comfortable.

This article will discuss the role of data collection while a companion article describes how placing a building’s services under atBOS control can address an overheating problem.

Assessing a building before renovations

Our view is that the first step in any renovation project is to fully understand the building as a dynamic entity in which its fabric, services and occupants interact to drive its behaviour. As described in detail in our white paper [PDF] on renovating a building to cut its carbon emissions, installing a sensor network captures data that can be used to build a detailed understanding of that behaviour. That model can then be used to plan renovations in a way that ensures the costs and increase in a building’s embodied carbon are paid back by savings in bills and operational carbon.

The building as a dynamic entity
The building as a dynamic entity

Such an approach is both informed by and compliant with the TM59 methodology, published by the Chartered Institute of Building Service Engineers (CIBSE) underpinning Part O’s dynamic thermal modelling method. Sensors continuously monitor the internal environment, including the temperature, enabling a designer to identify, evaluate and plan the best way to mitigate an overheating problem. For example, if a room overheats when it receives direct sunlight, solar gains can be mitigated by external shading but if the overheating problem can be traced to hot water pipework, the solution may be to improve the pipe’s insulation or temperature control may only be possible using mechanical ventilation or air conditioning.

Among the parameters that atBOS records, room occupancy is critical because the TM59 definition of unacceptable overheating is based on how much time a room spends over a threshold temperature while it is occupied. A model based on atBOS sensor data includes a precise record of how often each room is occupied for, avoiding spending money that would only mitigate overheating in unoccupied rooms.

Demonstration of compliance

The atBOS sensor network collects and stores continuous data on the indoor environment which can either confirm that a building is compliant with the Part O regulations or that it is not, in which case it can inform the renovations needed to address its overheating problem.

Because atBOS records both the indoor temperature and whether a room is occupied, its data can be used to assess the TM59 definition of overheating which is based on a room’s temperature during occupied hours only. Without direct measurement of occupancy, the designated building control body may require the assumption that rooms are occupied for much longer than they actually are, which may lead to a requirement to over-ventilate those rooms or to install larger and more energy-hungry aircon units than are needed.

Atamate against overheating

Data collected by atBOS can identify the most cost-efficient and effective way to comply with Part O during a renovation and it can also be used for post-occupancy evaluation to confirm that overheating has indeed been mitigated. The next article will describe how atBOS can control building services to keep a building comfortable with the minimum energy expenditure.

Ask us for more

If you’d like to know more about how Atamate can help to mitigate overheating in buildings, ask us on the form and we'll be happy to discuss it.

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