Building Regulations Approved Document F1 Means of Ventilation April 2006

Transcription

1 Building Regulations Approved Document F1 Means of Ventilation April 2006

2 BPD Structure BUILDING PRODUCT DESIGN LTD 4 trading divisions.. Natural ventilation products and systems Roofing products, flat and pitched roofilights building membranes and accessories Damp proof course and related products Aluminium Louvres and Solar Shading

3 The Purpose Of Ventilation Provision of outside air for breathing Dilution and removal of airborne pollutants, including odours Control of excess humidity arising from water vapour in the indoor air) Provision of air for fuel burning appliances (which is covered under Part J of the Building Regulations) Provision to control thermal comfort

4 Building Regulations Building Regulations Part F1 (1995) Requirements

5 Main Changes in 2006 Requirement F2 Condensation in Roofs has been moved to Part C (Now C2(c)) A performance based approach has been adopted. The provisions have been designed to ventilate buildings having air permeability down to 3m_/h/m 50 Pa Increased guidance for domestic mechanical and natural ventilation systems. Ventilator areas are now described in terms of equivalent area, instead of free area.

6 Terminology Free Area: the geometric open area of a ventilator Equivalent area: a measure of the aerodynamic performance of a ventilator. It is the area of a sharp edged orifice which air would pass at the same volume flow rate, under an identical applied pressure difference, as the opening under consideration

7 Free Area is essentially a geometric area. A 4,000mm_ tricklevent has an aperture of 4,000mm_. Unfortunately, this does not reflect the airflow performance of the ventilator. The more complicated the passage of air, the lower the amount of air through it. As an approximation the free area is typically 25% greater than equivalent area.

8 Main Changes in 2006 (continued) Guidance given for Purge Ventilation. Guidance given for ventilation of basements in dwellings. Replacement windows should be fitted with trickle ventilators or an equivalent level of background ventilation.

9 Building Regulations Approved Document F1 Means of ventilation April 2006 Requirement Means of ventilation F1.- There shall be adequate means of ventilation provided for people in the building. Limits on application Requirement F1 does not apply to a building or space within a building: a. into which people do not normally go: or b. which is used solely for storage; or c. which is a garage used solely in connection with a single dwelling.

10 There are now three main ways of complying with Part F A. Providing pre-designated airflow rates Extract ventilation to the outside from each kitchen, utility room and bathroom and for sanitary accommodation. The extract can be intermittent or continuously operating. Highest & lowest settings no less than table 1.1a.

11 A. Providing pre-designated airflow rates (continued) Table 1.1a Extract ventilation rates Room Minimum intermittent extract rate Continuous extract Minimum high rate Minimum low rate Kitchen 30 l/s (adjacent to hob); or 13 l/s Total extract rate Utility Room 60 l/s (elsewhere) 30 l/s 8 l/s must be at least the whole building Bathroom 15 l/s 8 l/s ventilation rate in Sanitary accommodation 6 l/s Table 1.1b Whole building ventilation rate for the supply of air to the habitable rooms in a dwelling should be no less than specified in table 1.1b. Table 1.1b Whole building ventilation rates Number of bedrooms in dwelling Whole building ventilation rate (l/s)

12 A. Providing pre-designated airflow rates (continued) Purge ventilation provision in each habitable room (extract provisions are sufficient in other rooms e.g. kitchens, bathrooms). Which is capable of extracting a minimum of four air changes to per hour (ach) per room directly to the outside.

13 B. Following the system guidance set out within the approved document System 1 ~ Background ventilators & Intermittent extract fans System 2 ~ Passive stack ventilation System 3 ~ Continuous mechanical extract System 4 ~ Continuous mechanical supply and extract with heat recovery (MVHR)

14 System 1 ~ Background ventilators & Intermittent extract fans

15 System 1 ~ Background ventilators & intermittent extract fans Table 1.1a Extract ventilation rates Room Minimum intermittent extract rate Minimum high rate Kitchen 30 l/s (adjacent to hob); or 13 l/s 60 l/s (elsewhere) Utility Room 30 l/s 8 l/s Bathroom 15 l/s 8 l/s Sanitary accommodation 6 l/s Continuous extract Minimum low rate Total extract rate must be at least the whole building ventilation rate in Table 1.1b

16 System 1 ~ Background ventilators & intermittent extract fans Table 1.2 a Equivalent ventilator area for dwellings (mm?) Total floor area (m?) Number of bedrooms a ,000 35,000 45, ,000 30,000 40, ,000 30,000 35, ,000 35,000 35, ,000 40,000 40, ,000 45,000 45,000 45,000 55,000 > 100 Add 5,000 mm? for every additional 10 m2 floor area For a single storey dwelling up to 4 storeys above ground level add 5,000mm_

17 System 1 ~ Background ventilators & intermittent extract fans Worked Example ~ Ground Floor Flat Assumptions Cooker hood adjacent to cooker hob Gross internal volume 83 m_ Floor area 36 m_ 2 person occupancy Side hinged windows 1.0m high & openable to 60

18 System 1 ~ Worked example Background ventilators & intermittent fans Intermittent extract Room Kitchen Bathroom Intermittent extract rate 30 l/s (adjacent to hob) 15 l/s Background ventilation For single storey ground floor dwelling of 36 m_ floor area the equivalent background ventilation area is 30,000mm_

19 System 2 ~ Passive stack ventilation

20 System 2 ~ Passive stack ventilation Table 1.2b Passive stack ventilators Room Internal duct diameter (mm) Internal cross sectional area (mm?) Kitchen ,000 Utility room 100 8,000 Bathroom 100 8,000 Sanitary accommodation 80 5,000

21 System 2 ~ Passive stack ventilation Table 1.2 a Equivalent ventilator area for dwellings (mm?) Total floor area (m?) Number of bedrooms a ,000 35,000 45, ,000 30,000 40, ,000 30,000 35, ,000 35,000 35, ,000 40,000 40, ,000 45,000 45,000 45,000 55,000 > 100 Add 5,000 mm? for every additional 10 m2 floor area Step 1: Determine the equivalent ventilator area for the dwelling Step 2: Make an allowance for PSV airflow (allow 2,500mm_ per stack) Step 3: Equivalent area required = step 1 - step 2

22 System 2 ~ Passive stack ventilation Worked Example ~ Ground Floor Flat Assumptions Cooker hood adjacent to cooker hob Gross internal volume 83 m_ Floor area 36 m_ 2 person occupancy Side hinged windows 1.0m high & openable to 60

23 System 2 ~ Worked example Choose appropriate Passive stack ventilation provision Room Internal duct diameter (mm) Internal cross- Sectional area (mm?) Kitchen ,000 Bathroom 100 8,000 Background ventilation Step 1: From table 1.2a the equivalent area is 30,000mm_ Step 2: With 2 no. passive stacks an allowance of 5,000mm_ can be made Step 3: 30,000-5,000 = 25,000mm_

24 System 3 ~ Continuous mechanical extract

25 Continuous extract System 3 ~ Continuous mechanical extract Step 1: Determine the whole building ventilation rate from Table 1.1b Table 1.1b Whole building ventilation rates Step 2: Number of bedrooms in dwelling Step 3: The required extract rates are as 1 follows: Whole building ventilation rate (l/s) Calculate the whole dwelling air extract rate at max operation (Table 1.1a) Max rate (e.g. boost ) should be at least the greater of step 1 & step 2 Min rate should be at least the whole building rate step 1 Table 1.1a Extract ventilation rates Room Minimum intermittent extract rate Minimum high rate Kitchen 30 l/s (adjacent to hob); or 13 l/s 60 l/s (elsewhere) Utility Room 30 l/s 8 l/s Bathroom 15 l/s 8 l/s Sanitary accommodation 6 l/s Continuous extract Minimum low rate Total extract rate must be at least the whole building ventilation rate in Table 1.1b

26 System 3 ~ Continuous mechanical extract Background ventilators 2,500mm_ equivalent area per room... Except wet rooms from which air is extracted

27 System 3 ~ Continuous mechanical extract Worked Example ~ Ground Floor Flat Assumptions Cooker hood adjacent to cooker hob Gross internal volume 83 m_ Floor area 36 m_ 2 person occupancy Side hinged windows 1.0m high & openable to 60

28 System 3 ~ Worked example Continuous extract Step 1: Whole building ventilation rate is 13 l/s Step 2: Whole dwelling extract rate is 21 l/s (kitchen & bathroom) Step 3:! Maximum rate (e.g. boost) is at least 21 l/s (with a min of 13 l/s in the kitchen & 8 l/s in the bathroom)! Minimum rate is at least 13 l/s (spread between the kitchen and the bathroom) Background ventilation Background ventilators of at least 2,500mm_ equivalent area in the living room & bedroom

29 System 4 ~ Continuous mechanical supply & extract with heat recovery (MVHR)

30 System 4 ~ Continuous mechanical supply & extract with heat recovery (MVHR) Step 1: Determine the whole building ventilation rate from Table 1.1b allow for infiltration by subtracting multi-storey dwellings: 0.04 x gross internal vol of the dwelling heated space (m_) single-storey dwellings: 0.06 x gross internal vol of the dwelling heated space (m_) Table 1.1b Whole building ventilation rates Number of bedrooms in dwelling Whole building ventilation rate (l/s)

31 Step 2: Calculate the whole dwelling extract rate at maximum operation by summing the individual room rates for minimum high rate from Table 1.1a Table 1.1a Extract ventilation rates Room Minimum intermittent extract rate Minimum high rate Kitchen 30 l/s (adjacent to hob); or 13 l/s 60 l/s (elsewhere) Utility Room 30 l/s 8 l/s Bathroom 15 l/s 8 l/s Sanitary accommodation 6 l/s Continuous extract Minimum low rate Total extract rate must be at least the whole building ventilation rate in Table 1.1b Step 3: The required airflow rates are as follows: the maximum extract rate (e.g. boost ) should be at least the greater of step 1 and step 2. Note the maximum individual room extract rates should be at least those given in Table 1.1a for minimum high rate; the minimum air supply rate should be at least the whole building ventilation rate in step 1.

32 System 4 ~ Continuous mechanical supply & extract with heat recovery Worked Example ~ Ground Floor Flat Assumptions Cooker hood adjacent to cooker hob Gross internal volume 83 m_ Floor area 36 m_ 2 person occupancy Side hinged windows 1.0m high & openable to 60

33 System 4 ~ Worked example Continuous supply & extract Step 1: Calculate the whole building ventilation supply rate i. From the table, the air supply rate = 13 l/s ii. Allow for infiltration by subtracting 0.06 x internal volume (m_) Ventilation rate = x83 = 8 l/s Step 2: Calculate the whole dwelling air extract rate at maximum operation 21 l/s (assuming extract in kitchen & bathroom) Step 3:! Maximum rate (e.g. boost) is at least 21 l/s (with 13 l/s in the kitchen & 8 l/s in the bathroom)! Minimum rate is 8 l/s

34 Purge ventilation Adequate purge ventilation may be achieved by the use of openable windows and/or doors.

35 Windows For a hinged or pivot window that opens 30 or more, or for sliding sash windows the height x width of the opening part should be at least 1/20 of the floor area of the room. For a hinged or pivot window that opens less than 30, the height x width of the opening part should be at least 1/10 of the floor area of the room. Approved Document B ~ Escape window provisions

36 Purge ventilation External Doors (including patio doors) For an external door, the height x width of the opening part should be at least 1/20 of the floor area of the room. Windows & doors in one room The areas of the openable parts may be added to achieve 1/20 of the floor area of the room

37 Purge Ventilation Worked Example ~ Ground Floor Flat Assumptions Cooker hood adjacent to cooker hob Gross internal volume 83 m_ Floor area 36 m_ 2 person occupancy Side hinged windows 1.0m high & openable to 60 For all 4 ventilation systems With an opening angle of 60 gives 1/20 of floor area. E.g. Living room of 13.5m_ ~ the window opening area should be at least 0.68m_

38 C. Using other ventilation systems provided that it can be demonstrated to the building control body that they satisfy the Requirement e.g. by showing that they meet the specified moisture and air quality criteria.

39 Ventilation systems for basements For a dwelling with a basement connected by a large permanent opening (e.g. an open stairway): Treat the dwelling and basement should be treated as a multistorey dwelling For a dwelling with a basement that is not connected by a large permanent opening: a. The part of the dwelling above ground should be considered separately and ventilated as a dwelling. b. The basement should be treated as a separately as a singlestorey dwelling above ground.

40 Work on existing buildings Unless ventilated adequately by other installed ventilation provisions, all replacement windows should include trickle ventilators Alternatively an equivalent background ventilation opening should be provided in the same room Night latches are not recommended as an alternative. Ventilation opening should be controllable and at least equal to that originally provided.

41 Work on existing buildings Where there was no ventilation opening or or where the original opening size is not known the following minimum size should be adopted: Dwellings: habitable rooms ~ 5,000mm_ equivalent area kitchen, utility room and bathroom (with or without WC) ~ 2,500mm_ equivalent area

42 In Summary Part F is now performance based. Designed for buildings have an air permeability of 3m_/h/m 50 Pa. Is more prescriptive with regards the use of other systems Passive Stack Ventilation, Continuous MEV and Heat Recovery. Background ventilation now based on equivalent area and the size & potential occupancy levels of the dwelling. Specific guidelines for purge ventilation Replacement windows now require trickle ventilators

43 Any Questions?

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