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 provide design advice. This policy details the conditions under which we submit our 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. 


Design Considerations



Where Ventec Systems Ltd provide a design for an Aspirating Smoke Detection System, the design is intended to validate the correct operation of the air sampling pipe network and detector(s), in accordance with the relevant manufacturers flow calculation software and is not intended as a design for a Fire Alarm System.


Any design provided will generally take into account the recommendations of BS5839, BS6266, EN54-20 and the FIA Code Of Practice for Aspirating Smoke Detection Systems where applicable but it is the recipients' responsibility to ensure that the design is fully compliant with the relevant standards.

ASD Assessment

We carry out an initial assessment of all drawings that we receive. We attempt, wherever possible, to ensure that our design complies to the relevant British Standard and tender/project requirements, however, we may make certain assumptions: -

  • Scaled Drawings: While every effort is made to determine the correct scale of any drawings provided, we may estimate scales and cannot guarantee or accept responsibility for the accuracy of any dimensions, calculations or equipment quantities based upon our estimated scales. All dimensions & quantities should be checked and verified on accurately scaled drawings before using any information within our designs and/or flow calculations. 

  • Specifications: We will attempt to follow any specification provided but cannot guarantee that advice and/or information provided by us meets the specification. If no specification is provided, we will offer the most suitable equipment based on sensitivity, performance, reliability, and costs. It is the recipient’s responsibility to ensure that any design provided by us 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 design will target Class C detection.

  • Protected Area: If the protected ASD area is not clearly defined we will propose a solution based upon the most likely area of protection which should be checked for accuracy.

  • Sampling Holes: 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 EN-54 class C.

  • Building Height: Where the height of the protected area is not specifically advised to us, we will make an estimation of the pipework height. Pipework lengths, quantities and detector suitability should be thoroughly checked by the recipient to validate our estimated heights.

  • Building Features: 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 recipient’s responsibility to ensure suitability and compliance.

  • Air Flow: Our design assumes that there are no air pressure differentials and that there is a normal free flow of air throughout the protected environment. 

ASD Design


  • Pipe Network Design: If no specific pipe routes, pipe layouts and/or sampling hole locations are supplied, we will provide a design based upon a proposed concept. All pipe and sampling hole locations should be checked for compliance with the relevant standards. Ventec Systems do not accept responsibility for the correct positioning of air sampling points to any applicable standards.

  • Zone Size: Subject to scale, we will assess the size of the protected area. If the area is in excess of British Standards, we will advise the use of multiple detectors if possible. Zone sizes and ASD coverage area should be checked by the recipient for compliance and may require variations to standards.

  • Interfacing: Unless specifically requested otherwise, any equipment that we detail will be suitable for indicating and signalling Fire & Fault conditions, via LED’s and relays, to a conventional or addressable Fire Alarm Control Panel.

  • Standby Times: Power supply standby times will generally be calculated for a 24-hour standby period and should be checked and/or calculated by the responsible fire alarm designer.

  • Flow Calculations: All ASD designs will be calculated through the respective detector manufacturers design software or flow guides. Ventec Systems cannot accept any liability for design issues caused by incorrect software algorithms or software bugs.  


Contact Information


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