FEEDBACK consultants, contractors and FMs into each PDT, so the manufacturer only needs to complete this information once for a product type. The uses of that information feed into the design, procurement, delivery and construction phases, without further effort by the manufacturer. Where we can, we have mapped our parameters onto the BuildingSmart Data Dictionary, the repository on which IFC fields are based. Around half of the parameters our expert teams identified were not in that dictionary hence why we have not used only the COBie requirements, but the stated requirements of members of the design and construction supply chains. We have offered our findings of new field requirements to BuildingSmart, but its reaction times are limited by the consensus building process that surrounds new additions to the IFC Schema. Love thy neighbour This month, readers discuss BIM data, heat pumps, and electric vehicles in tunnels Mine of information Re: BIM information from manufacturers (CIBSE Journal, November 2018), it seems that CIBSE and the Society of Digital Engineering have jumped into this issue too quickly, and focused on the MEP industry, without looking at the wider picture. Product Data Templates (PDTs) are only really useful for the construction and handover of a project. The article doesnt address the similar issues faced with asset management information. BIM means we should be able to export the design information to aid in the operation of the building. However, BIM files received from manufacturers typically have different naming and measurement conventions. If manufacturers produced product information to the Construction Operations Building Information Exchange (COBie) format, you could easily extract data into PDTs, while transferring the information into asset management databases. COBie is a non-proprietary data format for the publication of a subset of BIM focused on delivering asset data, as distinct from geometric information. This, in theory, should not only work for MEP products, but for all construction items. Euan Brownlie Carl Collins, digital engineering consultant, CIBSE, responds: Join the conversation We want to hear from you. Talk to us. @CIBSEJournal CIBSE LinkedIn www.cibse.org Subscribe to our newsletter Receive our top stories about building services engineering. Sign up at cibsejournal.com In an ideal world, COBie would be the delivery mechanism for product data, but the IFC Schema upon which it is based does not have adequate fields to properly describe building services products. We have focused on building services because that is the sector CIBSE represents. There are similar efforts being carried out by other organisations for example, the Landscape Institute is also on a PDT mission. We are confident that the use cases for PDTs are wider than information exchange at construction and handover. We have collated fields deemed important by I have a question for the heat pump gurus about the dilution of whichever source from which energy is extracted. If heat pumps are to be used in dense conurbations, how serious is this degradation? For an air source heat pump, energy is extracted from the local atmosphere, which is cooled and which, therefore, increases all nearby buildings heat losses. For a solid ground source, the ground is cooled and a similar problem exists, unless heat pumps dump heat to the ground from cooling during the summer. The problems may be less for groundwater and river-based sources, but in the Netherlands where large quantities of water flow through the gravel from which their systems extract heat there is a measurable downstream effect. In all cases, there is the potential for affecting ones neighbours, though a ground source would probably be the worst. River authorities have their restrictions, but for the other two sources there would probably be a slow reduction in the degree and extent of the urban heat island. But how far will it go when everything from transport to lighting is reducing its energy consumption? Will people ask for ancient heat legislation analogous to ancient lights law, or sue their neighbours for nuisance? The conclusion must be that implementation should be limited possibly restricted to carefully tested locations and that we should concentrate first on insulation. John Moss MCIBSE Tunnel vision Should a review of use of existing tunnels happen once electric vehicles outnumber those with internal combustion engines? As oxygen consumption and CO2 and NOx will be reduced massively, will formerly unusable tunnels become viable without special ventilation? Has research been carried out into this? Bruce Latimer CIBSE Journal welcomes readers letters, opinions, news stories, events listings, and proposals for articles. Please send all material for possible publication to: editor@cibsejournal.com or write to: Alex Smith, editor, CIBSE Journal, CPL, 1 Cambridge Technopark, Newmarket Road, Cambridge CB5 8PB, UK. We reserve the right to edit all letters. 14 December 2018 www.cibsejournal.com CIBSE Dec18 pp14 Letters.indd 14 23/11/2018 15:54