BYTNAR - TALKS
EPISODE 022 - APPROVED DOCUMENT F - VENTILATION VOLUME 1 AND VOLUME 2
This episode is for people who want to know more about Approved Document Part F – Ventilation Volume 1 and Volume 2
You should like this episode if you ask yourself questions like:
What are the ventilation requirements for dwellings and non-dwelling buildings according to Approved Document F?
How should mechanical ventilation systems be commissioned to meet building regulations?
What are the exemptions from ventilation requirements in Approved Document F, and which types of buildings are excluded?
What is the difference between Volume 1 and Volume 2 in Approved Document F?
How do you ensure adequate extraction and supply of fresh air in a building while preventing the infiltration of external pollutants?
What is purge ventilation, and how can it be achieved using natural or mechanical methods?
How does upgrading the building envelope affect natural ventilation, and what holistic approaches should be considered?
What are the testing and commissioning standards for ventilation systems in new or renovated buildings?
What are the special ventilation considerations for car parks, offices, and large congregation spaces?
This is Bytnar Talks the Engineer Takes on Construction Episode 22 hi I'm Piotr Bytnar each day I help my clients plan and design building projects through Bytnar Limited a Consulting Chartered Structural Engineers practice my biggest passion and the corner stone on which I've built my business is finding clever solutions for construction projects I am a chartered structural engineer and a bing software developer so you can rest assured that I will strive to talk about the best practices and the use of new technologies in the industry and if you're embarking on a construction project or are involved in planning designing and building the world around us you'll find this podcast useful approv document F ventilation volume 1 and volume two hi and welcome to bitnar talks your favorite podcast on all matters of architecture engineering and construction it is Friday the 28th of June 2024 and I am here back with you with the 22nd episode and information on approved document F ventilation volume 1 and volume two before we dive deep into this week's episode let let us recap the last episode for Reference last week I talked about the approved document DN e toxic toxic substances and resistance to sound to recap quickly requirement D1 is all about cavity insulation and potential of insulation polluting the indoor air by of gasin of UA UA for Mal had died approv document e resistance to the pass of sound with is with four requirements and regulation 4d1 requirement E1 deals with sound from other parts of the building and adjoining buildings it basically sets the design must provide reasonable resistance to sound from adjacent parts of the building and adjoining buildings requirement E2 deals with sound within a dwelling house it says internal walls and Floors must resist soundr transmission particularly between bedrooms and living rooms requirement E3 deals with re rever oh that's one is a horrible one reverberation in common internal parts we need to prevent excessive reverberation in common areas like corridors and stairwells in residential buildings requirement E4 then goes on to deal with acoustic conditions in school well it actually does not really as it reference as to follow standards set by the Education Act 1996 and department for Education regulation 41 deals with sound insulation testing it tells us that the Sound Performance testing is required for new buildings and certain material changes with results submitted to building control some exemptions apply if using robust details being approved methods in this episode I will move to the approved document F and the consideration for ventilation in dwellings and buildings other than dwellings so without further Ado let's dive into the text of the approved document [Music] F in this episode I will talk about the statutory guidance contained within the approved document f ventilation the episode will follow its standard format for the material talking about the approved documents I will first read you the text of the actual regulation and then we go Section by section giving you a little bit of a commentary or including auxiliary information where appropriate well knowing me it may be inappropriate information from time to time but don't worry most of it is a good information anyway the document consists of two volumes Volume One deals with dwellings and volume two with buildings other than dwellings both volumes deal with the requirements through five sections section 0 to 4 and reference regulation 39 and 42 44 the volume one adds regulation 42 regulation 39 puts an obligation on the provision of information regarding the ventilation system and its maintenance regulation 42 puts an obligation on testing of the mechanical ventilation efficiency in the new dwellings so-called airflow rate testing and regulation 44 puts obligation on notification of commissioning of the mechanical ventilation system to the appropriate building Control Authority unless the work carried out cannot be tested I we got the flavor of the topic now so let's get into the Nitty Gritty of the approved document [Music] so starting with the text of the legislation Part F ventilations means of ventilation requirement f1.1 there shall be adequate means of ventilation provided for people in the building point two fixed systems for mechanical ventilation and any Associated controls must be commissioned by testing and adjusting in as necessary to secure that the objective referred to in sub paragraph one is met requirement F1 does not apply to a building or space within a building a into which people do not normally go B which is used solely for storage or C which is garage used solely in connection with a single dwelling so simple simple reading that is followed by a white interpretation as usual in the G the air within the dwelling needs to be refreshed and cleaned of vapor and pollutants internally generated vapor and pollutants need to be removed and the exterior pollutants infiltration minimized this generally means a provision of trickle ventilation mechanical ventilation in the rooms where vapor and pollutants are released and Purge ventilation throughout start starting with Section zero which eases us into the document its structure and understanding we are straight up being told that the volume one is for dwellings and that dwellings means self-contained units no sharing toilets or kitchen anyone there are number of circumstances where the requirement F does not apply including schedule two buildings Crown buildings statut Tre Undertakers and airports C certain small additions police and some small building extensions there are naturally expectation rules some certain rules and limits applicable to all these cases as may be the case with historical buildings too note that emergency repair work does not need to be notified prior to work taking place and some minor Works do not require notification also but in any case require needs to be met as however the interpretation of the requirement contained within this document May interact with other requirements and in such case the higher expectation guidance should be followed section one informs us of the required ventilation rates in the situation of reasonable external equality it is important to provide the right level of ventilation but equally so to maintain a habitable level of Noise Within the dwellings and this point concerns the ventilation units itself the ducting but also the noise outside the levels should be low at 30 DB for noise sensitive rooms and 45 DB for less noise sensitive rooms measured to BS h233 standard or BSN 13141 in case of hedge VX systems there is no point point of having a system that cannot be maintained but the requir voice they need to provide sufficient access for maintenance so so we are safe and sound on this occasion aren't we typically the ventilation will be provided by targeted extraction of the air from kitchens bathrooms and utility rooms or any other room where elevated level of pollutants or water vapor can be present whole dwelling vent vation and Purge ventilation needs to be provided as and when needed all types can be provided by natural means using stock effects mechanical means or a mixture of both the purchase from the guidance can be made just as long as the performance is Justified the performance criteria of pollutant and moisture concentration are given in appendix B of the document but the guidance goes as far as prescribing the perform forms of ventilation system which correlates with the achievable air quality standards background ventilators standard references equivalent area in millim squared and requires conspicuous marking of the figure on the ventilator itself for verification purposes extract ventilation is required in all typical circumstances like kitchens bathrooms utility rooms and sanitary accommodation the performance is given in lit per second are are different of for continuous system and that for intermittent system and should gently be fitted at the highest point but not lower than 400 MM below the ceiling this does not include cooker Hood which should be generally installed to manufacturer specifications or between 60 60 to 75 cm over the Hop surface theic requirements for ventilations of kitchens is either 60 l/ second if no if there's no cooker hood or recirculation filter Hood used in the kitchen then we need to use an extractor with 30 L pers second capacity when extracted to the outside down to 30 l/ second for continuous ventilation utility rooms should either go by 30 or 8 L per second bathrooms 15 or 8 and sanitary accommodation one figure of 6 l/ seconds or perge otherwise the dwelling should be supplied with air by either Supply funds or background ventilators at the minimum of 0.3 L per M squared of internal thr area or minimum rate for the number of rooms starting at 30 30 L per second for studio apartments to 43 L per second for a five-bedroom unit plus 6 l/ second for every additional room so calculate either by me squared or by prescription of bedrooms whichever is greater that's the requirement for Air ventilation to allow for the air circulation doors should be undercut by minimum of 10 mm when there are finishes on the floor when there's no finishes on the floor it should be 20 mm to allow for the finishing to be put at the later date Purge ventilation is required for all habitable rooms allowing four a changes per hour but may need to be greater the window or door opening needs to be at least 120th of the floor area if openable to 30% or more and below that range of the opening it needs to be at least one/ tenth of the of the floor area naturally a mechanical option is always on hand if we need it we are directed by the guidance to BN 13141 for determination of performance of the components of the system we intend to use the requirement assumes the background ventilation remains open and that we can control the ventilation either manually or automatically and that the background ventilation is at least 1.7 m above the flow level level to reduce cold drafts but not too high to inhibit manual operation basements may require additional consideration depending whether they are connected to the house and allow continuity of ventilation or not as well depending on the number of Expos facades of that basement in any case the basement may be treated as a single dwelling above the ground with a consideration for ventilation of at least one room even if there are no habitable rooms in that basement whatsoever mechanical ventilation may be required ventilation of inner rooms can be done through other room through permanent opening between the room of at least 12th of combined area of the rooms taken that the equivalent Purge ventilation is possible in the access room or the room is serviced by 10,000 mm square of equivalent backround ventilation depending on the system of of ventilation we choose for our dwelling the requirement will follow different levels of performance for Less airtight dwellings we can follow requirements for natural ventilation and for all dwellings either continuous mechanical extract ventilation including natural bankr ventilation or mechanical ventilation with heat recovery that means no natural background ventilation what is the less airtight dwelling you ask it is a dwelling that leaks air more than 5 m Cub per hour per meter squared at 50 pascals of pressure as designed or 3 m cubed as buil for highly ATI dwellings mechanical ventilation may be the only solution depending on the ventilation approach you will take the different limits of ventilation minimums and which are prescribed by the guidance certain situation may require BPO specifications and specialist input it goes without saying that the installation needs to be done to appropriate standards and commissioned in accordance with an approved procedure you will find a completion checklist and commissioning sheet with the appendix C of the is approved document this information should be completed by the installer section two Now deals with Ingress of external pollutants which needs to be kept to a minimum while at least within the boundaries of the air quality standard regulations 2010 the sources of pollution will vary from being next to the street close to exhaust of combustion from other dwelling construction sites or any other ex example the table showing typical pollutants exposure limit and exposure time is included within the guidance for the best solution we will need to consider the location of the building type of pollutant inlets and Outlets positions prevailing winds and so on the provision of mechanical and filtered Solutions may be the timate answer in the worst case scenario but no mention of such is given within the guidance when it comes to the relative humidity we talk about the measurements taken during colder months and the limit for a new dwelling house is between 65% relative humidity at 1 month's average to 75% at week's average and 85% at day average for existing buildings measurements at the internal pH of the external wall should show the surface water activity levels at the same same time intervals at 0.75 or 0.85 or 0.95 respectively this parameter allows determination of condition for mold growth in the wall by checking if the material material is rather drying or rather getting more moisture that molds needs to grow section three refers to work on existing dwellings which should should not change the building for walls but try to improve the quality wherever and whenever possible so for change of views we look into upgrading to the standard as well when we create new rooms we ought to be in line with the standard now making changes or otherwise improving on the envelope of the building may be inadvertently May inadvertently bring the ventilation level of the building to levels below the required by standard remember we need to get rid of bad air but bring some good air within and any Improvement very often seal the envelope inhibiting that access that trickle of air to within guidance comes to Aid with simple methods to assess the impact of improvement and gives us a checklist in appendix D for the identification of possible requirements for bringing the property in line with the regulations the checklist will like go over and above the expectations of the regulation but it's very handy and a starting point to to consider replacement of Windows should ensure sufficient background ventilation at least matching the one in existing windows but preferably that of a guidance or as close to the requirement as possible addition of rooms bathrooms wetrooms will have standard rep repercussions requiring the provision of enough ventilation but refurbishment to these rooms will not automatically trigger such requirements and if we are using the existing cabling we will not need to inform the building control of the work section four goes on to talk about the requirement f1.2 the regulations 39 42 and 44 the system needs commissioning and testing and recording according to standard procedures that's it end of story although the document goes on to describe the inspection standards for background ventilators and intermittent extract ventilation ducted system airflow rate test of all extract funds cooker hoods continuous extract and Supply funds and all terminals controls of the systems too the commissioning should end up with the preparation of operating and maintenance instruction transfer to the building owner together with the complete commissioning the manual suggests cleaning and maintenance intervals and all the auxiliary information that can assist in the operation and maintenance of the system some of the information should end up in the home user guide for new dwellings treating on the system in layman's terms [Music] now off to volume two and consideration for ventilation in buildings other than dwellings section zero of the document and the text of the legislation remain the same for both volumes so I will head straight to the in the G section of the episode and follow section one to 4 with a sneak peek into appendices so in the G's the Secretary of State considers the requirement fulfilled where the high water vapor or polluting rooms are well ventilated occupants of the building can enjoy minimum levels of outdoor Air Supply and are given an option for parage ventilation of occupied rooms and sanitary accommodation some occupiable rooms may need air quality monitoring the entry of external pollutant should be minimized and as however the system should be serviceable and maintainable and not to be too noisy or allow for drafts or Ingress of rain or be risky to heal section one lays down the provisions for ventilation in different types of buildings be it specific types of occupiable rooms offices car parks and others not offices and car Parks it's all about the pesky mle that can come about from too much Vapor or pollutants which can be wide on the Spectrum from stinky socks through flu to car carbon monoxide the ventilation system should be designed and done properly to avoid noisy scenarios and to allow due Maintenance and Service ventil ventilation generally follows the principles of extraction supply of fresh air purge ventilation and monitoring of indoor quality requirement can be achieved by means of natural or mechanical ventilation but should we choose to go the natural route the guidance reference as to the charted institution of Building Services Engineers applications manual 10 and manual 13 the consideration of performance level of the system are stated in appendix B and include considerations of Bio affluence as well as such measurements of exposure limits for carbon monoxide nitren nitrogen dioxide foral deide total volatile organic compounds and ozone you know printers we are also also guided to use CO2 monitors to verify the efficiency of ventilation in the given room naturally the approach will vary from room to room and may not always give right reading but for offices and where people breathe a lot being under 400 PS per million is considered a well ventilated space and reading over 1500 PS per minute will require Improvement again here the installation of the system needs to be good and needs to pass the commissioning stage the rooms that will need the monitoring of their air quality will be offices walk-in fridges assembly rooms restaurants concert halls and on and on basically wherever people spend their time and or congregate those are the rooms when monitoring will be needed preferable method of monitoring is by non dispersing infrared CO2 monitors but there are exceptions rooms that are small or large and the small room is considered that of of the volume of 125 M cubed or 50 square m of floor area and the large rooms are considered to be of over 800 M cubed volume or 320 M squared floor area and these do not fall under the of monitoring extract ventilation in offices should be provided in typical places of heightened pollution sanitary accommodation bathrooms washrooms food and beverage prep areas and printer rooms printer rooms should be created for heavy use of printers which means at least 30 minutes per hour and serviced with extraction of 20 L of air per second per machine and the whole building ventilation rate should be met sanitary accommodation and bathrooms should have an intermittent air extraction at the following limits of 15 L per second per shower or bath and 6 lit per second per WC pan or urino however the sanitary accommodation extraction should have an option to work continuously rules for remote kitchens are similar to that of domestic the kitchens with a 15 L pers second requirement if microwave and Kettle are in use only the rooms without openable Windows should have extraction working at that time of use and minimum of 50 minutes thereafter naturally specialist buildings and commercial kitchens will follow their own requirements the requirement of as high as possible but not lower than 400 MM from the ceiling ventilators for naturally vented perm premises is also applicable here but the passive stock ventilation terminals should be in the ceiling Air Supply for offices should be at least 10 L per second per person or 1 L per second per M square of floor area common areas in the office will need half a liter per second per meter square of the common area all natural ventilation opening of at least 2% of the floor area in more complic complicated scenarios of higher levels of pollutants the document refer us to cibz guide a environmental design Purge ventilation is a must for all offices and ventilation should be controlled either manually or automatically system generally should not recirculate air into other rooms unless it does so through UVC jdo irradiation system or heper filters when it comes to car pars the owners is to limit carbon monoxide concentration to maximum levels of 30 parts per meter in 8 hour period or 90 90 parts per meter in 50-minute Period at ramps and exits for naturally ventilated car Parks each level needs to have an equivalent area opening of 5% of the total floor area at that level level with the opposite side receiving at least 1A 25% of area each for carps with mechanical ventilation the opening can be reduced to 2 and a half% with ventilation capable to deliver free air changes per hour with the caveat for exit and Rams where cars can queue where the performance should be increased to 10 uh changes per hour order ventilation will need to be capable of six air changes per hour in general and 10 air changes at the position of car queing up it would be unnatural for the guidance not to refer us for further information to cibs HS AA and ashr AE guidances for other buildings we are generally referen to cibb guide a and to a two-page long table described being type of the room un expected performance of ventilation system or reference to further guidance you know things like for prisons go with the ministry of justice justice publication PSI 17-22 certified prisoner prisoner accommodation or schools and education will go with education School premises regulation 1999 among others section two minimizing the Ingress of exterior pollutant is verbatim to that of dwelling so I will not go through this here again section three work on existing buildings follows the logic of the dwellings but without consideration of typical dwelling like buildings and like additions of habitable rooms or conservatories section four is also similar but without regulation 42 and regards commissioning and providing information the commissioning process is required to be according to CI bsse commissioning code M with additional guidance from besi for duct work and form part of the entry energy consumption assessment for part L requirements and done together on one form the information of the system should be provided in the building log book and the copy of the commissioning sheet handed over to the building [Music] owner so this is it folks the approved document F ventilation volume 1 and two let's sum it up so generally speaking building must have adequate means of ventilation for occupants mechanical ventilation systems must be commissioned to ensure they meet the required objectives exemptions include spaces where people do not normally go buildings used solely for storage and gadgets for single dwellings are generally exempt Volume One deals with dwellings and goes on for five sections section zero when it applies to volume y one it applies to self-contained dwellings meaning units with no sheded kitchens or bathrooms certain building including historical structures a small extension can have specific exemptions or additional considerations emergency repair work and minor Works may not need prior notification but must still meet the requirements section one of that volume that deals with ventilation Provisions ensure adequate ventilation while maintain low noise levels of 30 DB for sensitive rooms and 45 DB for other rooms extra ventilations is generally required in kitchens bathroom utility rooms and sanitary accommodations minimum ventilation rates are specified for different types of rooms and scenarios Purge ventilation should be enabled should enable four air changes per hour with specific window or door opening requirements mechanical and natural ventilation methods are addressed with different requirements based on the building's air tightness section two of the volume external pollutants tells us to minimize incress of external pollutants within the boundaries of the air quality standard regulation 2010 it tells us to consider location pollution type inlets outlets and prevailing winds to name a few relative humidity limits are specified to control mold growth section three of that volume dealing with existing dwellings tells us that any changes should improve ventilation quality wherever wherever possible guidance includes assessing the impact of improvements and providing checklist for compliance replacement windows should maintain or improve existing ventilation levels section four deals with commissioning and information which tells that the system needs to be commissioned and tested to standard procedures with results recorded inspection standards for various ventilation components are outlined and operating and maintenance instruction should be provided to the building owner in volume two which in many cases is very similar to volume one the section zero treats about what Secretary of State considers considers fine by fulfilling the requirements and it's generally considered that if rooms with high moisture or pollutant are well ventilated occupants have enough outdoor Air Supply and options for Purge ventilations are available that's good enough the system should also be maintainable not too noisy and avoid DS or raining wrist section one similar to volume one this with ventilation provision different building types and that's that's where it differs here as we have several different building types that we that we treat treat a little bit differently includes offices and car pars have tailored ventilation requirements ventilation should avoid mold and pollutants be properly designed and allow maintenance extract Supply Purge ventilation and indoor air quality monitoring are required for certain rooms section two external pollutant this section basically mirrors that for the dwellings focusing on minimizing the increase of exter pollutant section three existing buildings similar to dwellings but without consideration typical to homes like habitable roof or conservatories section four this is about commission and provision of information also similar to to that of the dwellings but using different standard for commissioning and and Reporting commissioning should follow cips standards and be part of the energy assessment for part L system information should be included in the building log book and provided to the owner in the next episode we will move to approve document G sanitation hot water safety and water [Music] efficiency I hope you enjoyed this episode and that the considerations of the approved document F ventilation is more friend friendly with you now you have any questions if you have any question reach out to me on Linkin or send me an email I'm more than happy to help you out in betna we deal with planning designing and managing of your projects and we are always glad to facilitate a free initial consultation to steer you in the right direction visit www. bit. and reach out to us whether your question is if we can help you with your project or what should I do we will be able to give you a piece of non-obligatory advice at Bitner we help our clients design and execute their dream homes or Investments if your building is falling apart we can also help investigate the reasons behind and to provide you with an appropriate strategy design and specifications for the repair thank you again for listening please voice up your opinions I'm waiting for you on LinkedIn and I want to hear from you see you next week remember Bytnar Designs The World Around You, Toodloo!
Piotr Bytnar BEng (Hons) MSc CEng MIStructE
Chartered Structural Engineer who deals with the Architecture of buildings. His Master's Studies led him to an in-depth understanding of risk and contract arrangements in construction as well as specialist knowledge in soil mechanics.
He and his team help homeowners and property developers to design and deliver construction projects reducing waste in time and the cost. He believes that the construction project is an iterative process that can be well managed and it is best managed if all the aspects of the project definition and management are dealt with in-house or coordinated by one organisation. His team works to all stages of RIBA and ISTRUCTE stages of work and enables contractors to deliver projects on-site providing risk evaluations, methodologies for execution of works and temporary works designs.
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