Roberts Gorden Vacuum Assisted Linear - Manual (Page 66)

B LACKHEAT ® I NSTALLATION O PERATION AND S ERVICE M ANUAL
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the attention of the user or purchaser; instruct them in the
safe operation of the heater(s). Advise the user that if the
system is unflued, any reduction in the natural ventilation
of the building may require a flue to be fitted, or additional
ventilation grilles will be required.
14.6 ECA Approved Systems (Multiburner only)
On ECA approved systems, it must be verified that the
requirement of 91% net combustion efficiency is met.
Measurements of temperature and CO
2
concentration in
the exhaust gasses have to be done. The net combustion
efficiency calculates as follows;
100 - [ (t
E
- t
R
) (A/CO
2m
- B) ] = net combustion efficiency
t
E
- Exhaust Temperature °C
t
R
- Room Temperature °C
A - G20 = 0.37, G31 = 0.42
B - G20 = 0.009, G31 = 0.008
CO
2m
- Measured CO
2
Concentration %