Marc Nickels of Kingspan Technical Insulation discusses how one substantial source of embodied emissions – building services haulage and deliveries – can be reduced on residential developments.
The UK Green Building Council anticipates that by 2035, embodied carbon emissions may make up around half of total emissions from the built environment. Embodied carbon is the result of all the processes needed to construct, maintain and ultimately dismantle a building at the end of its life. These emissions are already considered within major sustainability standards and are expected to come under greater scrutiny through local planning measures (such as the London Plan) so it’s important that developers consider how they can be addressed.
One key source of embodied emissions during the construction phase is from the road haulage needed to transport materials to site. New research from Rider Levett Bucknall has revealed that by using thinner, more thermally efficient pipe and ductwork insulation solutions over lower performing alternatives, it’s possible to insulate far greater lengths of services from a single delivery. This can reduce the number of deliveries needed for a project and was shown to cut the emissions associated with their transport by as much as 66.67% for pipe insulation and 33.41% for duct insulation solutions.
EFFICIENT SERVICES
The key performance metric for insulation materials is their thermal conductivity (lambda). This is the measure of how well they prevent heat conduction at a given thickness. The lower the thermal conductivity of the material, the more effective it is at preventing this type of heat transfer, meaning a slimmer thickness can be used with no loss of performance.
In pipe and ductwork applications, insulation materials are typically required to limit heat losses from services to the rates provided in BS 5422:2009 as a minimum. In practice, the thermal conductivity of the materials can have a major impact on the thickness of insulation needed to achieve these values. For example, materials such as phenolic pipe insulation typically have a far lower thermal conductivity than that of alternatives such as mineral fibre. A comparison carried out on a typical low temperature hot water system (<95°C) showed that, in some cases, the lower performing mineral fibre pipe insulation needed to be twice as thick as the phenolic alternative to reduce heat losses to the same rate. These differences can become even greater where enhanced specifications of pipe insulation are required, as is often the case on heat networks.
Similarly, a comparison of heated ductwork lagged with mineral fibre with a pre-insulated phenolic ductwork system showed that to achieve a heat loss rate of 16.34 W/m2, a 22 mm thickness of the pre-insulated phenolic ductwork system was needed compared with a 40 mm thickness for the mineral fibre lagged ductwork.
By using thinner insulation, it should be possible to insulate greater lengths of pipe and ductwork with each delivery to site. This is especially important as many developers switch to heat networks, which require extensive pipework systems in addition to ventilation or air conditioning ductwork. Kingspan Technical Insulation commissioned RBL to carry out a study looking at how the efficiency of the pipe and ductwork insulation could impact the number of site deliveries and associated carbon emissions.
TOTAL COVERAGE PER LOAD
To understand this, RBL first looked at the total length of pipework or area of ductwork which could be insulated to BS 5422:2009 with a single delivery from a typical, 44 tonnes haulage vehicle.
The analysis of pipework products considered the pipe insulation, pipe insulation support inserts and all associated packaging. Two different solutions were assessed across a range of pipework systems and pipe diameters: mineral fibre pipe insulation, and phenolic pipe insulation.
The outputs showed that between 8.33% and 146.53% more linear metres of pipework could be insulated with the phenolic pipe insulation specification, depending on the pipework system type and pipe diameters.
RBL then looked at two different ductwork solutions including coupling systems for warm air and dual ductwork: sheet metal ductwork lagged with mineral fibre insulation, and pre-insulated phenolic ductwork.
This showed that between 33% – 40% additional square metres of the pre-insulated phenolic ductwork could be carried in a 44 tonne lorry.
CARBON EMISSIONS
Based on this analysis, RBL were then able to calculate the expected greenhouse gas (GHG) emissions associated with deliveries of the insulation solutions for a range of applications.
These calculations initially looked at the number of deliveries and associated GHG emissions when delivering pipe insulation and insulated pipe support inserts for 10,000 metre, 20,000 metre and 40,000 metre lengths of pipework. The results showed that total GHG emissions could be as much as 66.67% lower with the phenolic pipe insulation specification compared with the mineral fibre specification.
For the ductwork insulation solution comparison, RBL considered the number of deliveries needed to provide 1,000 m2, 2,000 m2 and 4,000 m2 areas of ductwork. Again, the results showed that the total GHG emissions with the pre-insulated phenolic ductwork could be up to 33.41% lower than the mineral fibre lagged sheet metal alternative.
They then carried out additional modelling based on the full building service specifications from several real-life case studies. This modelling assumed all materials were being sent from the same manufacturing site in Herefordshire and includes emissions from complete round journeys. The results supported those from the initial modelling, showing that emissions from pipework deliveries were reduced by half on the case study building, whilst those from ductwork could be cut by as much as 33.33%.
A FOCUS ON THE DETAILS
The extensive potential sources of embodied emissions can make it difficult for developers and housebuilders to know where to start when addressing this issue.
RBL’s study shows that by breaking the issue down into smaller focus areas, such as working with the building services engineers to consider the efficiency of building service insulation and its impact on haulage, it’s possible to achieve notable reductions in these emissions through relatively minor adjustments in specifications.
Marc Nickels is business development manager at Kingspan Technical Insulation