Properties of Air

For a burner originally adjusted to 15% excess air, changes in combustion air temperature and barometric pressure cause the following in excess air.

Air Temperature °F	Barometric Pressure in. HG	Resulting Excess Air %
40	29	25.5
60	29	20.2
80	29	15.0 Initial Setting
100	29	9.6
120	29	1.1
80	27	7.0
80	28	11.0
80	29	15.0 Initial Setting
80	30	19.0
40	31	34.5
60	30	25.0
80	29	15.0 Initial Setting
100	28	5.0
120	27	-5.5

*Expressed as a percent of Stoichiometric air required.