York DFAH Sizing Furnace Input, Natural GAS, Propane GAS, Gas Firing Rate Orifice Air Shutter

107272-UIM-B-1105

TABLE 18: High Altitude Duration Chart

NATURAL GAS

Elevation		56,000 — Input				70,000 — Input					77,000 — Input				90,000 — Input
		Orifice	Drill			Orifice		Drill			Orifice	Drill			Orifice	Drill
Feet	Meters			Part #					Part #				Part #				Part #
		Dia.	Size			Dia.		Size			Dia.	Size			Dia.	Size
Sea Level		0.136	29	9951--	1361	0.154		23	9951--	1541	0.161	20	9951	--1611	0.180	15	9951--	1801
2,000	618	0.136	29	9951--	1361	0.149		25	9951--	1491	0.157	22	9951--	1571	0.177	16	9951--	1771
3,000	914	0.128	30	9951--	1281	0.149		25	9951--	1491	0.157	22	9951--	1571	0.173	17	9951--	1731
4,000	1219	0.128	30	9951--	1281	0.147		26	9951--	1471	0.154	23	9951--	1541	0.173	17	9951--	1731
5,000	1524	0.128	30	9951--	1281	0.144		27	9951--	1441	0.152	24	9951--	1521	0.169	18	9951--	1691
6,000	1829	0.128	30	9951--	1281	0.144		27	9951--	1441	0.149	25	9951--	1491	0.166	19	9951--	1661
7,000	2134	0.120	31	9951--	1201	0.140		28	9951--	1401	0.147	26	9951--	1471	0.161	20	9951--	1611
8,000	2438	0.120	31	9951--	1201	0.136		29	9951--	1361	0.144	27	9951--	1441	0.161	20	9951--	1611
9,000	2743	0.120	31	9951--	1201	0.136		29	9951--	1361	0.140	28	9951--	1401	0.157	22	9951--	1571
10,000	3048	0.116	32	9951--	1161	0.128		30	9951--	1281	0.136	29	9951--	1361	0.152	24	9951--	1521
							PROPANE GAS
Elevation		56,000 — Input				70,000 — Input					77,000 — Input				90,000 — Input
		Orifice	Drill			Orifice		Drill			Orifice	Drill			Orifice	Drill
Feet	Meters			Part #					Part #				Part #				Part #
		Dia.	Size			Dia.		Size			Dia.	Size			Dia.	Size
Sea Level		0.082	45	9951--	0821	0.093		42	9951--	0931	0.098	40	9951--	0981	0.106	36	9951--	1061
2,000	618	0.081	46	9951--	0811	0.093		42	9951--	0931	0.096	41	9951--	0961	0.104	37	9951--	1041
3,000	914	0.078	47	9951--	0781	0.089		43	9951--	0891	0.093	42	9951--	0931	0.101	38	9951--	1011
4,000	1219	0.078	47	9951--	0781	0.089		43	9951--	0891	0.093	42	9951--	0931	0.101	38	9951--	1011
5,000	1524	0.078	47	9951--	0781	0.089		43	9951--	0891	0.093	42	9951--	0931	0.099	39	9951--	0991
6,000	1829	0.076	48	9951--	0761	0.086		44	9951--	0861	0.089	43	9951--	0891	0.098	40	9951--	0981
7,000	2134	0.076	48	9951--	0761	0.086		44	9951--	0861	0.089	43	9951--	0891	0.096	41	9951--	0961
8,000	2438	0.073	49	9951--	0731	0.082		45	9951--	0821	0.086	44	9951--	0861	0.096	41	9951--	0961
9,000	2743	0.073	49	9951--	0731	0.081		46	9951--	0811	0.086	44	9951--	0861	0.093	42	9951--	0931
10,000	3048	0.070	50	9951--	0731	0.078		47	9951--	0781	0.082	45	9951--	0821	0.089	43	9951--	0891

Table shows 4% Input Reduction per 1,000 ft. (304.8 m) Elevation. Reference Source: NFPA No. 54, ANSI Z 223.1, National Fuel Gas Code.

For Canadian high altitude {2000 - 4500 ft. (609.6 - 1,371.6)}, reduce gas manifold pressure to 3.0” w.c. (0.75 kPa) for Natural gas and for Propane gas.

SIZING FURNACE INPUT

The orifice spud supplied with all burners is the size for the minimum BTU input of the burner for the type gas shown on the rating plate. Table 18 shows the correct drill size for various inputs.

The correct manifold pressure for natural and LP gas is 3.5" w.c (0.87 kPa). Only minor adjustments in the input rate should be made by adjusting the pressure regulator. The minimum manifold pressure should be 3.0" w.c. (0.75 kPa) and the maximum pressure should be

3.5w.c. (0.87 kPa) the next size larger or smaller orifice size should be used if the desired input rating cannot be obtained within the above manifold pressure adjustment range.

TABLE 19: Gas Burner Settings

Gas	Firing Rate	Orifice	Air Shutter
(@ 3.5” W.C.)	BTU/Hr (kw)	Size	Setting
Natural	66,000 (19.3)	0.142” (3.61mm)	1.0
Natural	84,000 (24.6)	0.166” (4.22 mm)	3.5
LP	66,000 (19.3)	0.116” (2.95 mm)	2.0
LP	84,000 (24.6)	0.100” (2.54 mm)	3.5

NOTE: The BTU input valves in the above table show the approximate hourly input of the burner for the various drill sizes shown. To determine the actual input of the burner, turn off all other gas appliances.

32 Unitary Products Group