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Member questions: Closed water systems, chemical store ventilation and circular economyMay 2019

Compiled by Steve Sansom, Information & Knowledge Manager, BSRIA

Question: How often does a closed system need circulating if controlled via solenoid valves (creating dead legs if not opened)?

BSRIA guide Water Treatment for Closed Heating and Cooling Systems Section 2.2.2 Circulation states that:

  • The system control strategy should ensure that circulation pumps and control valves are periodically operated to reduce the risk of stagnation and ensure full distribution of all water treatment chemicals.
  • The minimum recommended period of circulation for heating and cooling circuits is one hour per day. Ideally this should be programmed into the building management system, where one exists. It is not necessary to operate boilers and chillers during this period.

This circulation frequency is also consistent with the Water Treatment and Conditioning of Commercial Heating Systems Guide (edition 1) from the Industrial and Commercial Energy Association where Section A8.3 Stagnation states:

  • During seasonal periods when the system is not required to run, it is recommended to set the BMS (out of hours) to run all parts of the system (Boilers off) for 1 hour every 24 hours.
  • Good application and design of three or four port valves is recommended to maintain good system circulation (for example at the ends of lateral runs).

Question: Do you have any information about ventilation rates in chemical stores for pools or any information on design?

Fresh air to chlorine storage areas may be provided via the use of natural or forced ventilation. Examples of natural ventilation would include air bricks or louvres; and forced ventilation might include an exhaust fan, ductwork and controls. Typically, 6 to 10 air changes per hour is needed,
depending on the size of room and the equipment within it.

You may find detailed information about ventilation requirements in the Health and Safety (HSE) document Safe handling of chlorine from drums and cylinders (second edition).

Question: BSRIA seems to be devoting much of its energies to tackling disruptions in construction. What information resources do you hold about the circular economy?

This is an excellent subject area and one BSRIA is aiming to make as much information as possible to support its members and the construction industry:

  • We can loan BS 8001 to any of our members dealing with the Circular Economy and order any British Standards for our members to access the latest information, advice and guidance
  • We employ on-site experts who can answer member queries
  • An expanding set of articles that we can send through and that can be ordered through the BSRIA website

Question: If I have bought a hardcopy of Spon’s Mechanical and Electrical Price Book 2019 from the BSRIA bookshop, can I also have an electronic version?

All bought copies of the print version of Spon’s Mechanical and Electrical Price Book contain a link to the electronic version on the inside cover, together will instructions on how to create an ID and password to access this. Please contact the BSRIA Bookshop to learn more about this at or telephone +44 (0) 1344 465522.

Question: Can I view BSI Standards in PDF format on the BSRIA website?

Currently, we don’t have a licence with BSI to offer digital format of standards to members; we can only loan the hardcopy version from our lending library. However, under copyright rules, we can
send contents pages to members electronically. Members may then view the contents pages and ask the library team to scan up to one fifth or one chapter of any standard, which will then be delivered
via email.

Contact the library team for more information: or telephone +44 (0)1344 465571.


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