acs

[bedspoolplayer]

hi there doing my acs shortly can anyone please refresh me on ventalion how to work it out please say 24kw -7kw what are the formuola please thanks in advanced just started doing gas again after long break

 

[paulnwales]

if you have a corgi manuall still look in there its explained really well.

 

[aggis]

Room ventilation

If 24 kw input gross [old boilers]

24 / 1.11 = 21.62kw net

21.62 - 7 = 14.62

14.62 x 5 = 73cm sq effective free air req'd

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If 24 kw input net

24 - 7 = 17

17 x 5 = 85cm sq effective free air req'd

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Compartment ventiation to outside

24kw net

High Vent. 24 x 5 = 120cm sq effective free air

Low Vent. 24 x 10 = 240cm sq effective free air

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Compartment to internal ventilation

High vent. 24 x 10 = 240cm sq effective free air

Low vent. 24 x 20 = 480cm sq effective fee air

Vent to room. 24 - 7 x 5 = 85cm sq effective free air

 

[fuzzy]

minus 7 time 5 usually

 

[mikegas]

As said but remember a dfe fire will require 100cm2 min regardles of kw, but always refer to manufacturers instructions

 

[capitanpugwash]

Also don't forget in the table for ventilation of flueless appliances (the one with cookers etc) that there is a column with 'opening window'. With most, there is a requirement to have an opening window too. Could catch you out.

For the rest refer to the tables.

In my head the 2 big questions were:

Compartment or Room
Outside or Inside Ventilation

Then into the corgi books to look at the pictures. If there is question on vents in series, start initially with the vent to outside and calculate this. After that, move onto the other internal vents which might be bigger depending on how many vents.

Good luck

 

[AlexGas]

Here's some info on DFE ventilation from BS 5871-3:2005
Specification for the installation and maintenance of gas fires, convector heaters,
fire/back boilers and decorative fuel effect gas appliances —
Part 3: Decorative fuel effect gas appliances of heat input not exceeding 20 kW (2nd and 3rd family gases)

8 Ventilation
8.1 General
The appliance shall have a supply of air for combustion and the safe operation of the flue.
COMMENTARY AND RECOMMENDATIONS ON 8.1
Subclauses 8.2, 8.3, 8.4 and 8.5 specify the ventilation requirements for appliances. It should be noted that
whilst BS 5440-2 excludes decorative fuel effect gas appliances from its scope, the references given in 8.3
and 8.5 to BS 5440-2:2000 are applicable in the context in which they are specified.
8.2 Sizing
Unless the manufacturer’s instructions specifically state that purpose provided ventilation is not required,
such ventilation shall be provided in the room or internal space containing the appliance. Where purpose
provided ventilation is required, the air vent free area shall be a minimum of 100 cm2, or, where greater,
as stated in the manufacturer’s instructions.
COMMENTARY AND RECOMMENDATIONS ON 8.2
Normally, appliances covered by this standard will require a minimum of 100 cm2 of purpose provided
ventilation. However, in the case of an appliance of not greater than 7 kW input which generates a clearance
flue flow not greater than 70 m3/h when tested in accordance with Annex A, an air vent may not be necessary.
The manufacturer’s instructions will provide details in such circumstances. It should be noted that Annex
A describes a laboratory test which is not for use by gas installers seeking conformity with this standard.

Hope it helps.

 

[kirkgas]

Also don't forget in the table for ventilation of flueless appliances (the one with cookers etc) that there is a column with 'opening window'. With most, there is a requirement to have an opening window too. Could catch you out.

For the rest refer to the tables.

In my head the 2 big questions were:

Compartment or Room
Outside or Inside Ventilation

Then into the corgi books to look at the pictures. If there is question on vents in series, start initially with the vent to outside and calculate this. After that, move onto the other internal vents which might be bigger depending on how many vents.

Good luck

i dont disagree with what you said, but would add a 3rd question, what type of appliance