ASD Design



Ventec Systems Ltd. are a supplier of specialist fire detection products to the UK fire trade & construction industry, primarily, a supplier of Aspirating Smoke Detection products. 

To provide quotations for the products that we supply, we do on occasion have to carry out material take-off and / or produce concept designs. This policy details the conditions under which we submit our design take-off based quotations.  




Appointed by Xtralis as a technical wholesaler of Vesda to the UK, a platinum partner with UTC for Airsense and a UK distributor for Wagner, Ventec Systems Ltd. aim to provide the best possible ASD solution to each individual project that we provide a quotation for. 




The quotations that we submit are based upon the documentation supplied, generally on the Request For Quotation (RFQ) detailed on the quotation that we submit. We do our best to check the suitability of the documentation submitted but we may make certain assumptions:-

  • Scaled Drawings: We always try to determine the correct scale of any drawings submitted but cannot guarantee the accuracy of any materials, dimensions, quantities and/or equipment that we detail and highly recommend that all dimensions are checked and verified before using any information within our quotation.

  • Specifications: If a specification is provided, we will attempt to follow it as best we can. If no specification is provided, we will offer the most suitable equipment based upon sensitivity, performance, reliability and costs. It is the responsibility of the company that receives and/or uses our quotation to ensure that it complies with any relevant specification.

  • Detector Class: If no EN54 classification is provided, we will estimate the most suitable class of detector for the individual project. If a classification cannot be established, our quotation will target Class C detection.


ASD Assessment


We carry out an initial assessment of any drawings that we receive. We will attempt, wherever possible, to ensure that any design concept that we supply complies to the relevant British Standard, however, It is the responsibility of the company using our quotation to ensure full compliance. 


  • If the protected ASD area is not clearly defined we will detail the most likely area of protection which should be checked for suitability.

  • Subject to scale, we will assess the size of the protected area. If the area is in excess of British Standards, we will use multiple detectors if possible. Zone sizes and coverage area should be checked and verified independently.

  • If there are no pipe routes, pipe layouts and/or sampling hole locations, we will add them where we deem appropriate. Any pipe and sampling holes added by us should be checked for compliance and are to be used for estimating quantities only.

  • Subject to scale we will always try to ensure that pipe layouts are within the tolerance for the detectors used. Pipe layouts are taken from 2D drawings and may not be accurate.

  • The locations of sampling pipes and sampling holes will be checked for compliance with the relevant British Standard where possible. If no standard is provided, we will check compliance with BS5839.

  • The number of sampling holes per detector will be checked against the relevant detector class limit. Where no class is defined, hole quantities will be checked against an assumed class. Where no specific class can be assumed, sampling hole quantities will be checked against class C.

  • Where the height of the pipework is unknown by us, we will take our best estimation of the building height. Pipework lengths, quantities and detector suitability should be thoroughly checked by the quotation recipient to validate our estimated heights.

  • Unless we are specifically instructed otherwise we will generally assume that all ceilings/roofs are flat with no Apex or structural obstacles. We do not examine drawings and/or specifications for roof details and it is the quotation recipients responsibility to bring any details to our attention.

  • Our concept estimating designs assume that there are no air pressure differentials and assume a normal free flow of air throughout the protected environment.


ASD Design


Where an ASD design/layout has been provided to us, a material take-off (MTO) will be carried out directly from the design. Scales and quantities of any MTO should be checked and verified. 


Where no design/layout has been provided, a concept layout will be created for estimating purposes and a material take-off carried out from the concept. A concept layout should not be relied upon as a design for an Aspirating Smoke Detection system and a full design from accurately scaled drawings should be carried out by the responsible fire alarm contractor.


Unless specifically requested otherwise, any equipment that we detail will be suitable for signalling Fire & Fault conditions, via relays only, to a conventional or addressable Fire Alarm Control Panel. Power supply standby times will generally be calculated for a 24-hour standby period. 

Due to the different specifications and requirements of different manufacturers, the material take-off is based upon pipe lengths, hole quantities and operational parameters of the respective aspirating detectors and may not be appropriate for other ASD systems not detailed within our quotation.


All layouts/designs should be checked and calculated through the respective manufacturer's calculation software prior to project commencement. Ventec Systems Ltd. are able to assist with specific calculations should our quotation prove successful.


Contact Information


Should you wish to know more about our design service, you can contact us here.

© 2020 Ventec Systems Ltd. | United Kingdom

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