Paragraph 2 Items required to be included in insulation works
Subject to the provisions of this paragraph and of paragraph 3 below, the insulation works done under this Scheme shall include the replacement by or conversion to double windows of all existing windows in each room in which there are to be insulation works under this Scheme in accordance with the specifications in paragraph 5 of this Schedule, and the provision and installation in each room in which there are to be insulation works under this Scheme of–
where there is no combustion appliance in the room or where one or more room sealed appliances and no other combustion appliance is in the room a permanent vent type “A” communicating directly with the external air at the highest level which is reasonably practicable in an external wall of the room conforming to the specifications in paragraph 8(5) of this Schedule, except that this paragraph shall not apply where a combined ventilator system is to be provided and installed under paragraph 4(1)(b) of this Schedule;
where an open fire and no other combustion appliance is in the room:
three permanent vents type “A” as referred to in paragraph 2(1) above, or
two permanent vents type “A” as referred to in paragraph 2(1) above, together with one inlet fan ventilator unit plus air supply duct with external cowl or grill as specified in paragraph 4(1)(a) of this Schedule and such further ventilation as may be recommended by the Solid Fuel Advisory Service, Davy House, Lion Road, Harrow on-the-Hill, Middlesex, HA1 2EX where the fire operates using solid fuel, or
one combined ventilator system as specified in paragraph 4(1)(b) of this Schedule and one permanent vent type “A” as referred to in paragraph 2(1) above;
where one or more flued combustion appliances, and no other combustion appliance, are present in the room and
where no mechanical ventilation is present or is to be installed, a permanent vent type “A” or an appropriate number of permanent vents type “A” as referred to in paragraph 2(1) above to provide a total effective area which shall not be less than the effective area in square millimetres calculated from 550H (where H is the total output rating in kilowatts of flued combustion appliances present in the room) so however that
the total effect area provided shall be not less than 3,250 square millimetres, and
the total effective area provided in square millimetres shall be not less than the cross-sectional area of flue connection in square millimetres;
where mechanical ventilation is to be installed, either
an inlet fan ventilator unit plus air supply duct with external cowl or grill as specified in paragraph 4(1)(a) of this Schedule, together with a permanent vent type “A” or an appropriate number of permanent vents type “A” as referred to in paragraph 2(1) above so that the total effective area provided by the permanent vent or vents shall not be less than the effective area in square millimetres calculated from 550H minus 3,250 (where H is the total output rating in kilowatts of flued combustion appliances present in the room) so however that
the total effective area provided by the permanent vent or vents shall not be less than 3,250 square millimetres, and
the total effective area in square millimetres provided by the permanent vent or vents added to 3,250 shall not be less than the cross-sectional area of flue connection in square millimetres, or
a combined ventilator system as specified in paragraph 4(1)(b) of this Schedule and, where necessary to ensure that the effective area of the air path through the combined ventilator system calculated in accordance with the provisions of paragraph 9 of this Schedule (together with the total effective area provided by any permanent vent or vents) shall not be less than the effective area in square millimetres calculated from 550H (where H is the total output rating in kilowatts of flued combustion appliances present in the room), a permanent vent type “A”, as referred to in paragraph 2(1) above, so however that the total effective area in square millimetres provided by the combined ventilator system and any permanent vent or vents shall not be less than the cross-sectional area of the flue connection in square millimetres;
where more than one open fire, or one or more open fires and one or more flue combustion appliances are present in the room and
where no mechanical ventilation is present or is to be installed, two or more permanent vents type “A”, as appropriate, as referred to in paragraph 2(1) above, so as to introduce combustion air ventilation into the room in sufficient quantity to ensure the safe operation of the combustion appliances, so however that the total effective area provided by the permanent vent or vents shall not be less than 6,500 square millimetres;
where mechanical ventilation is to be installed, either
an inlet fan ventilator unit plus air supply duct with external cowl or grill as specified in paragraph 4(1)(a) of this Schedule, together with a permanent vent type “A” or an appropriate number of permanent vents type “A” as referred to in paragraph 2(1) above, so as to introduce combustion air ventilation into the room in sufficient quantity to ensure the safe operation of the combustion appliances, so however that the total effective area provided by the permanent vent or vents shall not be less than 3,250 square millimetres, or
a combined ventilator system as specified in paragraph 4(1)(b) of this Schedule, and, where necessary to ensure that combustion air ventilation is introduced into the room in sufficient quantity to ensure the safe operation of the combustion appliances, a permenent vent type “A” or an appropriate number of permanent vents type “A” as referred to in paragraph 2(1) above.
Provided that–
Where a room to be insulated under this Scheme contains only a room sealed appliance or no combustion appliance, the airpath through the ventilator system and the vent type “A” may be made capable of being easily closed by a suitable means readily accessible within the room if in all other respects including standard of construction and installation, the ventilator system and vent type “A” when opened to the maximum extent conform to the standard of ventilation and acoustic performance specified in paragraphs 7 and 8 of this Schedule and, whether opened or closed, meet the requirements for electrical and fire safety referred to in paragraphs 7(5) and 8(4) of this Schedule;
the works may consist of, or include, items different from those specified in this paragraph if the standards of ventilation (including air admitted for the purpose of combustion) and acoustic performance provided by such items are not less than those which would have been provided by items specified in this paragraph;
where any items or part of an item is provided otherwise than under this Scheme and complies with the relevant specifications in this Schedule, it shall not be required to be duplicated as a condition for payment of a grant under this Scheme.