Riello Array AR 2000 - Appendix F - De-Rating for Altitude Installation

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APPENDIX
APPENDIX
APPENDIX F - DE-RATING FOR ALTITUDE INSTALLATION
When the appliance is installed at an altitude higher than 2000 ft, the fan speed must be set to the maximum of the available range in
any case and a de-rating of the input capacity must be considered in function of the altitude combined with the total length of the vent
and combustion air pipe as reported in the following table (input BTU/hr)
NOTE: The following chart compensates for the affects of altitude on the energy content of the gas supply. No additional de-rate
required.
ARRAY AR 1000
Altitude (ft) From 0% to 25% From 25% to 50% From 50% to 75% From 75% to 100%
0-2,000 1,000,000 1,000,000 1,000,000 1,000,000
3,000 917,896 901,967 886,035 870,105
4,000 887,540 872,047 856,645 841,243
5,000 857,004 842,131 827,256 812,383
6,000 826,557 812,212 797,866 783,520
7,000 796,112 782,296 768,478 754,661
8,000 765,665 752,376 739,087 725,800
9,000 735,220 722,461 709,701 696,939
10,000 704,773 692,541 680,310 668,078
ARRAY AR 1500
Altitude (ft) From 0% to 25% From 25% to 50% From 50% to 75% From 75% to 100%
0-2,000 1,500,000 1,500,000 1,500,000 1,500,000
3,000 1,376,845 1,352,950 1,329,053 1,305,158
4,000 1,331,174 1,308,071 1,284,967 1,261,864
5,000 1,285,507 1,263,197 1,240,885 1,218,575
6,000 1,239,836 1,218,318 1,196,799 1,175,281
7,000 1,194,169 1,173,444 1,152,716 1,131,992
8,000 1,148,498 1,128,565 1,108,631 1,088,700
9,000 1,102,831 1,083,691 1,064,551 1,045,409
10,000 1,057,160 1,038,812 1,020,466 1,002,117
ARRAY AR 2000
Altitude (ft) From 0% to 25% From 25% to 50% From 50% to 75% From 75% to 100%
0-2,000 2,000,000 2,000,000 2,000,000 2,000,000
3,000 1,835,793 1,803,934 1,772,070 1,740,211
4,000 1,774,899 1,744,094 1,713,290 1,682,485
5,000 1,714,009 1,684,263 1,654,513 1,624,767
6,000 1,653,115 1,624,424 1,595,732 1,567,041
7,000 1,592,225 1,564,592 1,536,955 1,509,323
8,000 1,531,331 1,504,753 1,478,175 1,451,600
9,000 1,470,441 1,444,921 1,419,402 1,393,878
10,000 1,409,547 1,385,082 1,360,621 1,336,256
To calculate the de-rating of the input capacity, follow this example:
We have an ARRAY AR 1500 boiler installed at 5,400 ft with a 6” ue system. The equivalent length of the vent pipe installed is 55 ft.
The equivalent length of the air combustion pipe installed is 35 ft.
The total equivalent length of the ue system is 55+35 = 90 ft. The maximum equivalent length for this type of installation is 100 ft (see
“Appendix I - Venting Size Data”).
The % range is 90/100 = 90%. This value is within the 75% and 100%.
Now the correct de-rating value is given from the value of the fourth column (From 75% to 100%) of the Array 1500 table that crosses
the row with 6,000 ft: 1,175,281 BTU/hr.