Insulation for Education - Part 1: Guidance on Thermal Comfort and Daylighting in the Learning Environment - Kingspan Insulation
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Welcome to part 1 of this 2 part CPD video on Insulation for Education, guidance on thermal comfort and daylighting in the learning environment. In this video we're going to be looking at the effective use of insulation in order to create an environment which safeguards well-being, whilst also limiting the running costs and environmental impact of education buildings with regards to thermal comfort and day lighting requirements.
Often designers can think that thermal comfort and a lighting will work against each other, insulating a building can mean thicker walls and as such less daylight. However, both are equally important for education buildings and can affect the learning capabilities of students and, by using a thinner insulation material that has a lower Lambda value both can be achieved.
In this video we will cover; the requirements of building bulletin BB101- guidelines on ventilation, thermal comfort and indoor air quality in schools; the thermal comfort recommendations in schools and how to meet building regulations part L; the effects thermal comfort can have on both the learner and the educator in a learning environment; and how to improve air tightness and reduce thermal bridging.
Kingspan insulation is part of the Kingspan group comprising five divisions we manufacture a suite of complementary building envelope solutions for both new build and refurbishment markets. Founded in King scored County cavern in Ireland in 1965 the group has expanded into a global business operating in over 70 countries, employing more than 14,000 people.
Data and Flooring Technology (formerly access floors) - 4% of the group product portfolio, world’s largest supplier of raised access flooring, custom manufactured data centre air flow systems including structural ceilings, air flow panels and containment.
Light and Air - 7% global leading provider of full suite of day lighting and energy efficient lighting, as well as natural ventilation and smoke management solutions.
Water and Energy (formerly environmental) - 5% market leading solutions for rainwater harvesting, wastewater management, hot water systems, environmental fuel storage and smart monitoring.
Insulated panels - 64% global leader in design development and manufacture of products and solutions providing thermally efficient and airtight insulated panel building envelopes.
Insulation board - 20% manufacture insulation boards pipe insulation and engineered timber systems. A wide product range suitable for a variety of applications in the domestic, non-domestic, new build and refurbishment sectors.
The Kingspan insulation division operates through a range of manufacturing sites in both the UK, across Europe and the rest of the world, which ensures a continuity of supply and manufacturing excellence. We have a total of 19 manufacturing sites, 23 sales offices and around 2,100 employees worldwide. Kingspan installations main site operates in Pembridge Herefordshire where we manufacture our Kooltherm, Therma and Optim-R our product ranges. We have another manufacturing site in Selby, Yorkshire to help service the North. Our Kootherm, Kingspan GreenGuard and TEK product ranges are manufactured here.
At Kingspan insulation we offer a comprehensive range of premium and high performance products to cover every application with minimal thickness from roofs, walls and floors to HVAC pipe and duct insulation to structural insulated panels.
Our product range includes:
Rigid phenolic boards with superior performance to any other rigid thermoset board for any application.
Rigid PR boards particularly useful in flat and tapered roof applications.
Vacuum insulation panels VIPs particularly useful in refurb and problem areas.
Rigid vacuum insulation panel encapsulated in high performance PR ideally used for roofing and flooring systems.
Fibre free rigid extruded polystyrene X PS insulation that has the necessary compressive strength for specialist applications such as heavy duty flooring, car park decks and inverted roofs.
TEK building system and TEK cladding panel
Structural insulated panels sips with PUR core offering speed of construction and low air permeability levels.
Pre insulated ductwork which is slim lightweight and easy to install.
Breathable membrane suitable for use in unventilated pitched roof and timber frame wall applications.
Insulation for Education
The environment of learner is exposed to varies greatly depending on the geographical location specification and size of the learning facility. What does not change however is the requirement for exceptional quality learning environments that enable the current and future generation of learners to reach their full potential.
Keeping students focused and on task is a daily challenge for anyone working within the education sector. This job is made even harder when the school building is working against you. A study by Tess and the Association of school and college leaders ASCL, found that more than 2/3 of England schools have buildings that are not fit for purpose.
According to research by RIBA in 2015 only 5% of 60,000 buildings in 18,000 schools surveyed in England, were in top condition performing as intended and operating efficiently. This report said that from damp leaky buildings to serious issues like exposure to asbestos too many pupils are trying to learn in classrooms that are damaging to their health and their education.
Building Bulleting (BB) 101 | Guidelines on Ventilation, Thermal Comfort and Indoor Air Quality in Schools
A poll by the key an independent organization that provides advice and support to school leaders and governors, found that in the UK more than 1/3 of head teachers feel their facilities are not fit for purpose. For the overwhelming part mould damp unnecessary loss of heat summer overheating lack of learning spaces and poor air quality are the primary reasons for this. Any one of these problems can detrimentally affect the attention span productivity and overall performance of both the learner and the educator.
In August 2018 the Education and Skills Funding Agency EFSA updated document building bulletin BB101 guidelines on ventilation, thermal comfort and indoor air quality in schools. It replaces building bulletin 101 (BB101) ventilation of school buildings 2006. BB101 describes the factors that affect the indoor environment of schools and gives recommended performance levels of compliance with UK regulations. It also provides non statutory guidance on how to design schools to achieve adequate performance for ventilation, indoor air quality and thermal comfort, thus creating effective teaching and learning spaces.
The EFSA have updated the guidelines to align with the latest health and safety standards and industry practice. They have also strengthened the guidelines to improve thermal comfort and indoor air quality with the aim of improving school buildings and lead to healthier outcomes for students.
The guidelines on thermal comfort include guidance on room temperatures and cold drafts in order to provide a comfortable environment, suitable for teaching and learning year round and, guidance on designing for children with disabilities who are less able to regulate their temperature than mainstream pupils.
And the guidance specific to insulation detailed calculation methods for thermal comfort, adaptive thermal comfort calculations have been introduced to prevent summertime overheating, based on the latest research on how people adapt to higher temperatures. These calculations use variable maximum indoor temperatures that depend on the outside temperature. This helps to avoid the unnecessary use of air conditioning by using passive measures such as night cooling and thermal mass to cool spaces in summertime.
We live and work 90% of our time in buildings so the design and construction of buildings should be focused around the aim of creating healthy buildings while there are a range of issues and design interventions that attribute to a healthy building, here at Kingspan we believe a healthy building includes being energy efficient, suited to the intended purpose of the building and, one that enables the people that work there to be productive and efficient or, in the case of educational health one that assists learning and well-being.
Energy efficiency in schools
Buildings represent a significant opportunity for carbon reduction in the UK. The Energy we use in them is responsible for almost half of the country CO2 emissions, 40% of Europe’s energy use and a third of its greenhouse emissions. Domestic buildings are important but so are offices factories, schools and hospitals. They make up 18% of the UK CO2 emissions and use 300 terawatt hours of energy per year, which is equivalent to the primary energy supply of Switzerland and, because they are usually bigger than domestic properties energy efficiency measures are more cost effective.
With a squeeze on school budgets it has never been more important for local authorities to identify low cost ways to deliver high financial savings. Reducing energy consumption is one of the quickest and simplest ways to deliver direct savings and could help the average secondary school save £21,500 in energy bills, almost equal to the annual salary of a newly qualified teacher.
Improving energy efficiency in schools does not mean compromising the comfort of staff and students. In many cases implementing some simple energy saving measures actually improves conditions as well as saving money. As you can see from the figures shown on screen space heating represents the largest opportunity for savings in school, making up 58% of energy usage, with lighting representing 8%. Getting the right temperature in a room can be difficult while it is not the only factor to consider effective use of insulation materials can help designers to meet the new requirements for thermal comfort, delivering excellent Indoor Environmental Quality IEQ.
Thermal Comfort - BS EN ISO 07730: 2005
In BS EN ISO 77302: 2005 ergonomics of the thermal environment, thermal comfort is loosely defined as being a personal condition of mind, which expresses satisfaction with the thermal environment. Put more simply it is the measure of whether a person feels neither too hot nor too cold.
This definition is inherently problematic for designers as it requires them to cater for the subjective opinions of everyone in the room. Especially when the bodies thermal balance can be affected by a wide range of environmental and personal factors.
- Air temperature
- Mean radiant temperature
- Location and direction of air movement
- Turbulence intensity
- Relative humidity
As such in addition to environmental factors they must also take into account personal factors, physiological factors, psychological factors, clothing insulation and metabolic rate which is a function of age, body shape and activity. To predict the thermal comfort of a large group of people BS EN ISO 07730: 2005 uses two indices, predicted mean vote PMV and percentage people dissatisfied PPD. The PMV and PPD indices predict the thermal comfort of people working in a reasonably steady state environment. They are the most widely used indices for condition buildings in British, European and international standards, especially where mechanical cooling is provided.
The PMV predicts the mean response of people within the same environment and the PPD gives a quantitative measure of how many of these people would be dissatisfied with the comfort of the environment.
The PMV predicts the mean response of people within the same environment considering both the environmental and personal factors we've just covered, to generate a score on a 7 point comfort scale from hot +3 to cold -3.
The PPD can then be calculated based on the PMV score the percentage of people dissatisfied will exponentially increase as PMV moves away from the central comfort scale score neutral zero. Advice from an environmental engineer will be needed on thermal comfort issues regarding the building fabric and the heating and ventilation systems.
Thermal Comfort - BB101
The Thermal Comfort criteria for schools within BB101 user version of the adaptive thermal comfort standards within the BS EN ISO 077302: 2005 which has been modified for school environments. During the heating season BB101 sets out clear recommended operative temperatures for rooms between 17 and 25°C, depending on what the space is used for. One of the simplest ways to maintain these temperatures during these months is by achieving a high level of thermal performance in all areas of the building envelope. This will help to reduce reliance on heating systems cutting energy demand and bills.
Impact on Health and Performance of Students | BS EN ISO 15251: 2007
BS EN ISO 15251: 2007 indoor environmental input parameters for design and assessment of energy performance of buildings, addressing indoor air quality thermal environment, lighting and acoustics, details that the energy consumption of a building depends significantly on the specification for both the indoor environment, temperature, ventilation and lighting and the building design, and operation including systems.
It explains that indoor environment also affects health productivity and comfort of occupants. The standard reference is recent case studies which have shown that the cost in terms of absenteeism, reduced comfort and losses in productivity of a poor indoor environment within a building for an employer, building owner and for society as a whole, is often considerably more than the cost of the energy used by the same building. It concludes that a good indoor environment can improve overall work and learning performance and reduce absenteeism
A report by the Institute of education University College London evaluated the effects of thermal conditions and indoor air quality on health comfort and cognitive performance of students.
The report examined evidence that thermal conditions may have acute and adverse effects on student’s health, which can indirectly affect performance through impaired concentration, attendance and discomfort.
The evidence provided in the report suggested that lower temperatures in the range between 25 and 20°C improved students’ performance in terms of speed by 2 to 4% for every 1°C reduction. In addition, their report found but the cognitive performance of pupils improved by 6 to 8% where thermal comfort was improved.
Another report by professor Peter Barrett at the University of Salford Manchester concluded that a well-designed classroom could boost a pupils learning progress by up to 16% over the course of a year.
The report found that naturalness, i.e. Light, temperature and air quality, are the predominant factors impacting student development and progress. Ensuring good thermal comfort within today's schools is therefore essential to the education of today's learners.
Thermal Comfort Criteria for Schools
The thermal comfort criteria for schools within BB101 uses a version of the adaptive thermal comfort standards within BS EN ISO 7730: 2005 which has been modified for school environments. These variable maximum indoor temperatures depend on the room use.
The normal maintained operative temperatures during the heating season range from:
- 17°C for areas where there is a higher than normal level of physical activity, sports halls and sleeping accommodation, toilets, circulation spaces and stores rooms that are normally occupied.
- 20°C for kitchen preparation areas and spaces with normal levels of activity teaching, study, exams, admin staff areas, prep rooms, practical spaces and computer suites.
- 21°C for spaces with less than normal level of activity or clothing including sick, isolation rooms, changing rooms, and gymnasia, and dance and movement studios.
- 23°C where pupils or adults may be wet and partially clothed for a significant length of time such as swimming pools.
Considerations also have to be made for young children under five years old and also special schools where pupils tend to be complex and varied, including pupils with physical difficulties or profound and multiple learning difficulties.
To maintain the recommended operative temperatures during the heating season usually the space must either be heated or cooled. However, some education buildings are defined as free running this means they are not actively heated or cooled but rather use natural ventilation to manage internal temperature.
In England most schools are free running outside of the heating season, this corresponds to the 1st of May to the 31st of September.
NB if the school is a free running building an overheating risk assessment ORA should be carried out. This is set out in CIBSE TM52 the limits of thermal comfort, avoiding overheating in European buildings.
Outside of the heating season BB101 uses adaptive thermal comfort outlined in BS EN 15251:2007 where the maximum indoor temperatures change from day to day depending on outside temperatures.
By increasing the thermal efficiency of our buildings this has decreased the need for heating but on the other hand can increase the need for cooling.
Therefore, in addition to providing ventilation systems which can be controlled by staff in each classroom during the daytime or particularly for free running buildings, BB101 recommends introducing a clear night purge strategy, using passive and active measures to cool the thermal mass of building elements.
Thermal mass describes a materials capacity to absorb store and release heat. Materials such as water and concrete have a high capacity to store heat and are referred to as high thermal mass materials.
Insulation foam by contrast has very little heat storage capacity and is referred to as having low thermal mass. Slab soffits in teaching and other densely occupied spaces will often need to be exposed to provide thermal mass to absorb heat and provide night cooling to prevent summertime overheating. This is particularly important in hotter locations such as urban heat islands.
Heat islands are areas in cities such as in a London which have a lot of thermally massive buildings and roads which heat up and do not cool quickly overnight, leading today and night temperatures that can be much higher and surrounding suburban and rural areas.
Night purge strategy a senior researcher from the land Institute a non-profit research education and policy organization reported that world consumption of energy for cooling, due to rising temperatures could explode tenfold by 2050.
With this increased demand for cooling systems in mind consequently impacting climate change a night purge strategy offers a more economic and environmentally friendly solution. This type of strategy involves utilising cool night-time air to cooler building overnight. This is typically implemented via windows vents and louvers using natural ventilation.
NB further information on this can be found in section 4.13 of BB101, which references the requirements for exposed thermally massive building fabric and means of controlling a night purge strategy.
Passive and active measures to cool the thermal mass of a building.
Used to maintain comfortable building temperatures are the basic design elements of a building, they maximise the use of natural sources of heating cooling and ventilation, example measures include the use of insulation air tightness natural light solar gain and natural ventilation.
Look to actively reduce carbon and make use of active building service systems, example measures include renewables and energy saving sophisticated controls such as, smart thermostats, solar lights and mechanical ventilation. Passive measures generally create buildings which consume less energy however, most buildings and less built with this specifically in mind will generally include both active and passive measures, to cool and heat the thermal mass of the building.
Dynamic Thermal Modelling
Dynamic thermal modelling involves building a 3D computer model of a building. The 3D simulation should be consistent with the building's design and specification. It should be used to assess buildings for overheating risk and to size ventilation openings. In depth modelling like this can predict internal comfort conditions, identify the likelihood of overheating during summer months, established likely heating demands and maximise available natural light via daylight calculations.
This information helps architects to design effective and efficient buildings both in terms of the environmental impact and, cost involved. However regardless of whether an education building is free running or not, maintaining a constant temperature inside a room will be more efficient and cost effective if the building is adequately insulated. Measuring the efficiency of a building envelope can be done by calculating a U-value.
The 'Whole Building' Approach
The basic criteria to demonstrate compliance with the energy efficiency requirements of the building regulations comprise a mix of mandatory requirements and legislative guidance. The building regulations in part L don't just look at the performance of individual elements such as roof wall and floor U-values, rather it adopts a whole building approach that looks at use, air permeability, ventilation, thermal bridging, solar gain, occupancy, orientation and building services working together. This approach allows flexibility in how compliance is achieved but it is essential that a basic standard of building envelope performance is maintained. And so, limiting fabric standards have been set to give an assurance of absolute minimum performance. Limits are also set for building services.
Carbon Footprint - Calucating the difference between Actual and Target Emissions
One of the first requirements for demonstrating compliance is the need to show the design CO2 emissions for the whole building, referred to as the building CO2 emissions rate BER and calculated based on actual specification does not exceed the minimum allowable standard for the energy performance of a building, referred to as the target CO2 emission rate TER, defined by the annual CO2 emissions of a notional building of the same size and shape to the proposed building. The resulting measurement is expressed in kilograms of carbon dioxide per square meter per year.
TER & BER calculations for buildings other than dwellings should be carried out in accordance with the national calculation methodology NCM, preferably using the simplified building energy model SBEM, if the design features are capable of being adequately modelled by SBEM.
All in all, the goal is of course to show that the quality of construction is such that the energy performance of the actual building matches or exceeds that estimated by the design. It is also important to remember individual building fabric elements and fixed building services must achieve specified energy efficiency backstop standards, which limit design flexibility. Although meeting these standards won't automatically make your building compliant, failing to meet any of these minimum standards will mean it fails to be compliant.
The one constant throughout the life of the building is the fabric so it is absolutely crucial that this performs to a high level and maintains a good level of energy efficiency regardless of other systems. This fabric first approach also helps to avoid the need to rely on less dependable factors such as, air permeability and heat loss, increasing the likelihood of compliance.
Building Regulations - Part L
Building regulations and standards set the levels of thermal insulation required when carrying outbuilding work either for new build or refurbishment projects. These are expressed as a U-value which needs to be achieved. A U-value is the measure of heat loss through a building element walls, floors or roofs. A U-value measured in Watts per square metre Kelvin, chose the ability of an element to transmit heat from a warm space to a cold space in a building and more specifically from outside to inside a building. If an element has a higher thermal resistance it will lower the U-value.
The lower the U-value the better insulated the building element is. Section 2.1.2 of BB101 references building regulations part L, approved document L2A conservation of fuel and power in new buildings other than dwellings and requires that the criteria laid out in the aforementioned document be followed for educational buildings.
On screen you can see the suggested U-values for non-domestic new build constructions in England, Wales and Scotland.
Guidance is also provided for the renovation and refurbishment of thermal elements within education buildings. Where a thermal element is renovated the performance of the whole element should be improved to achieve or better the target U-value set out in this table. Provided the area to be renovated is greater than 50% of the surface of the individual element or 25% of the total building envelope.
On screen you can see the targeted U-values for non-domestic extension and refurb constructions in England, Wales and Scotland. The two figures given for England and Wales for walls depend on the type of wall construction are U-value of 0.55 Watts per square metre Kelvin, is used for cavity insulation and 0.30 Watts per square meter Kelvin for internal and external wall insulation.
Airtightness and Thermal Bridging
In addition to U-values air tightness and thermal bridging can also affect the efficiency of the building fabric, as referenced in section 4.11 of BB101.
Avoid Thermal Bridging
A thermal bridge can be defined as an area that has greater or lesser heat transfer than adjacent areas. When calculating the energy and emissions performance of a building three types of thermal bridges are considered, repeating linear and point linear, non-repeating and point nonrepeating. Repeating thermal bridges occur where there are regular interruptions within a building fabric, by materials with poorer insulating properties e.g. timber studwork or I beams in a timber frame wall construction, or fixings and fasteners. The differing typically additional heat flow incurred by repeating thermal bridge, is accounted for in the U-value calculation for the building element containing the bridge. These U-values are then used in SAP calculations.
Linear non repeating thermal bridges occur at intermittent points in the building fabric where either the thermal insulation layer is discontinuous e.g., sills and jams around the windows in a masonry cavity wall construction. Or, where the outside surface area of a construction is different from that of inside surface area, e.g. at the corner of two adjoining external walls.
The differing heat flow typically but not always greater than that through the adjoining plane elements attributable to the thermal bridge is the linear thermal transmittance of the bridge, measured in Watts per meter Kelvin referred to as psi value. The lower the psi value the better the performance. These psi values are accounted for in SAP.
Air tightness or air permeability is expressed in terms to air leakage in cubic metres per hour per square metre of external surface area, when the building is subjected to a differential pressure of 50 pascals. The air leakage is the unintentional flow of air through cracks and gaps in building fabric.
Excessive air loss can add to the energy consumption of the building as the most air within the envelope will have been heated and this is replaced by colder air, which then needs heating with associated costs, and added carbon emissions.
Adequate ventilation needs to be achieved alongside good air tightness and this needs to be sufficient to ensure a comfortable and healthy environment, as ventilation removes or dilutes pollutants that accumulate in the building as well as additional moisture from occupants and their activities.
One way in which thermal bridging and air tightness can be prevented is by a detailed fabric first design approach using high performance insulation to encapsulate the whole building so to retain the heat within the building and improve energy efficiency.
When insulating the building it is important to consider what will happen at the junctions between its roofs, walls, floors and openings in order to reduce the impact of thermal bridges wherever possible through good detailing and by using appropriate construction techniques.
The key factors to consider are:
- Insulation continuity,
- Overlapping of insulated layers,
- Using materials with a better lower thermal conductivity,
- Consideration of air permeability or air tightness,
The effects of linear thermal bridging include condensation, mould growth and eventual deterioration of internal linings. In order to meet the requirement for more thermally efficient education buildings it is essential to pay close attention to detailing.
This will not only ensure the energy performance of an education facility is met via reduced thermal bridging, but also minimised the potential issues and their associated risks.
That concludes Part 1 of this 2 part CPD video, in which we've covered:
- The requirements of building bulletin BB101 guidelines on ventilation thermal comfort and indoor air quality in schools
- the thermal comfort recommendations in schools and how to meet building regulations part L
- the effects thermal comfort can have on both the learner and educator in a learning environment
- and how to improve air tightness and reduce thermal bridging.
Part 2 will cover:
- Daylighting and the impacts on health will being an performance
- Insulation solutions to meet the thermal comfort and daylighting requirements within an educational building
- The requirements of building bulletin BB100 designed for fire safety in schools
- Case studies showing practical examples of how effective use of insulation can be achieved in various learning environments
Thanks for watching part one and if you would like further information or details of any of the references made in this video, you can get in touch with us via any of the contact methods on screen now.