BUILDING REGULATIONS

The Regulations cover Natural and Mechanical Ventilation

The areas to which Mechanical Ventilation applies are:

Domestic

Habitable room

Kitchen

Utility

Bathroom

Other Sanitary Accommodation separate from Bathroom

Non-domestic

Occupiable room

Kitchen

Bathroom including shower rooms

Other Internal Sanitary Accommodation

To implement the requirements of an EU Workplace Directive part K has been split into Domestic and Non-domestic buildings.

As a consequence of this, the term occupiable rooms is introduced to provide for rooms such as:

Office, Workroom, Classroom, Hotel bedroom

INTERACTION OF MECHANICAL EXTRACT WITH OPEN-FLUED HEATING APPLIANCES.

Mechanical ventilation can suck flue gases back into a room from a heating appliance. This could happen at a leaking joint in a flue spigot or flue section or entrance into a chimney for example. Recommendations:

(a) Seal flue outlet from oil-fired boiler

(b) For gas-fired heating appliance - max. 20 litres/second mechanical ventilation rate.

(c) No mechanical extract in same room as solid fuel appliance.

DOMESTIC BUILDINGS

Use CONTROLLABLE BACKGROUND VENTILATION everywhere by installing:

v Trickle Vents in windows

v Air Bricks with “hit and miss” ventilator

v Other

Use a PASSIVE STACK VENTILATION system.

Passive Stack Ventilation (PSV) may be used as an alternative to mechanical extract ventilation in:

KITCHENS

BATHROOMS

SANITARY ACCOMMODATION

Passive Stack Ventilation (PSV)

System shall be designed and constructed in accordance with BRE information Paper 13/94.

Definition

Passive Stack Ventilation (PSV) is a ventilation system using ducts

from the ceiling of rooms to terminals on the roof, which operate by a combination of the natural stack effect, ie the movement of air due to the difference in temperature between inside and outside, and the effect of wind passing over the roof of the dwelling.

OPEN FLUED HEATING APPLIANCES

Open-flued heating appliances take their combustion from the room where they are installed and so contribute to the extract ventilation when in operation.

Mechanical extract ventilation need not be provided in a room where there is either:

(a) an open flued appliance which provides the primary source of heating, cooking or hot water production, or

(b) an open flued appliance min. 125mm dia (approx) with permanently open air inlets.

OPENING WINDOW IN KITCHENS

An opening window is to be provided as a supplement to extract ventilation.

1/20 th of floor area.

VENTILATION FOR COMMERCIAL AND INDUSTRIAL - NON-DOMESTIC BUILDINGS

Note - Large Kitchens see CIBSE guide B2.3 and B2.11

For example B2.3 - Kitchens, hotel and industrial

Total air supply rate, not less than 17.5 litres per m2 of

floor space, not less than 20 air changes per hour.

VENTILATION OF SPECIALIST ACTIVITIES

(a) School or other educational establishment.

(b) Workplaces

(c) Hospitals

(d) Building Services plant rooms

(e) Rest rooms where smoking is permitted

(f) Commercial Kitchens

(a) School or other educational establishment.

Fume Cupboards - DFE Design Note 29

(b) Workplaces

Specific workplaces and work processes - HSE Guidance Note EH22

(c) Hospitals

Specific rooms in hospitals - DHSS Activity Data Base and Department of Health Building Notes 4,21 and 46.

(d) Building Services plant rooms

If emergency ventilation is required to disperse contaminating gas releases

· HSE Guidance Note EH22.

(e) Rest rooms where smoking is permitted

Min. 16 litres/second per person in addition to requirements of Table 3.1

(f) Commercial Kitchens

Examples:

For a Kitchen which measures 5 metres x 4 metres x 2.4 metres high, 60 litres per second is equivalent to 4.5 air changes per hour.

For a bathroom which measures 3 metres x 2 metres x 2.4 metres high, 15 litres per second is equivalent to 3.75 air changes per hour.

Other guidelines:

C.I.B.S.E. Guide

BRE Digest 398 1994

Continuous Mechanical Ventilation in Dwellings:

Design, installation and operation.

1. Discusses ducted extract and/or supply ventilation running continuously.

2. Less reliance on natural ventilation.

3. Better control of ventilation rate means less wasted energy.

4. Opportunity for heat recovery system as shown in diagram.

5. Dwelling must be fairly airtight.

6. A total ventilation rate for the whole house of 0.5 air changes per hour is typical.

BS 5925:1991

Code of Practice for

Ventilation principles and designing for natural ventilation