Engineering Bulletin
AIRFLOW DATA
(CFM & TEM PERATRUE RISE vs. EXTERNAL STATIC PRESSURE
NOTES:
• CFM in charge is without filter(s). Filters do not ship wit h this furnace, but must be provided by t he installer. If t he furnace requires t wo return filt ers, this chart assumes bot h filt ers are installed.
• All furnaces ship as high-speed cooling and medium-speed heating. Installer must adjust blower cooling and heat ing speed as needed.
• For most jobs, about 400 CFM per t on when cooling is desirable.
• INSTALLATION IS TO BE ADJUSTED TO OBTAIN TEM PERATURE RISE WITHIN THE RANGE SPECIFIED ON THE RATING PLATE.
• This chart is for informat ion only. For satisfactory operation, external st at ic pressure should not exceed value shown on t he rat ing plate. The shaded area indicates ranges in excess of maximum stat ic pressure
allowed when heating.
• The above chart is for U.S. furnaces installed at 0-2000 feet. At higher alt itudes, a properly derat ed unit will have approximat ely the same tem perat ure rise at a part icular CFM , while Esp at the CFM will be
low er.
*MSS96/*CSS96
0.6 0.7 0.8
AC CFM RISE CFM RISE CFM RISE CFM RISE CFM RISE CFM CFM CFM
HIGH 3. 0 1478 N/ A 1418 25 1354 26 1290 28 1208 29 1129 1040 930
MED 2. 5 1299 27 1265 28 1225 29 1167 30 1112 32 1033 949 841
MED-LO 2. 0 1081 33 1064 33 1039 34 997 36 945 38 886 819 722
LOW 1. 5 966 37 951 37 925 38 892 40 861 41 808 750 666
HIGH 3. 0 1432 37 1374 39 1319 40 1237 43 1157 46 1063 958 854
MED 2. 5 1289 41 1250 43 1204 44 1142 47 1066 50 981 897 789
MED-LO 2. 0 1080 49 1057 50 1022 52 980 54 926 58 861 785 700
LOW 1. 5 967 55 945 56 919 58 879 61 844 63 789 712 632
HIGH 3. 0 1620 44 1561 46 1478 48 1401 51 1322 54 1239 1150 1052
MED 2. 5 1538 46 1476 48 1401 51 1332 53 1250 57 1166 1083 992
MED-LO 2. 0 1446 49 1388 51 1333 53 1258 57 1197 59 1112 1037 937
LOW 1. 5 1246 57 1217 58 1165 61 1128 63 1067 N/ A 994 938 840
HIGH 4. 0 1746 41 1671 43 1589 45 1516 47 1447 49 1371 1295 1160
MED 2. 5 1190 60 1179 60 1151 62 1138 62 1090 65 1042 970 879
MED-LO 2. 0 894 N/ A 877 N/ A 867 N/ A 870 N/ A 863 N/ A 831 764 671
LOW 1. 5 624 N/ A 595 N/ A 620 N/ A 620 N/ A 610 N/ A 604 571 519
HIGH 5. 0 2233 32 2159 33 2086 34 2024 35 1941 37 1850 1753 1651
MED 4. 0 1820 39 1778 40 1742 41 1695 42 1638 43 1551 1485 1384
MED-LO 3. 5 1571 45 1535 46 1497 48 1446 49 1402 51 1338 1280 1204
LOW 3. 0 1361 52 1333 53 1290 55 1255 N/ A 1208 N/ A 1171 1104 1051
HIGH 5. 0 2157 41 2087 43 2028 44 1953 46 1858 48 1775 1661 1558
MED 4. 0 1907 47 1852 48 1800 49 1738 51 1675 53 1605 1514 1410
MED-LO 3. 5 1608 55 1580 56 1493 60 1501 59 1440 62 1367 1296 1219
LOW 3. 0 1390 N/ A 1344 N/ A 1326 N/ A 1268 N/ A 1227 N/ A 1194 1132 1071
HIGH 5. 0 2204 48 2144 50 2080 51 1991 54 1914 56 1817 1724 1595
MED 4. 0 1938 55 1914 56 1849 58 1778 60 1713 62 1645 1548 1454
MED-LO 3. 5 1651 65 1624 66 1574 68 1529 70 1475 72 1409 1331 1236
LOW 3. 0 1427 75 1382 N/ A 1345 N/ A 1311 N/ A 1272 N/ A 1215 1159 1066
HIGH 3. 0 1425 25 1345 26 1271 28 1198 30 1138 31 1051 945 864
MED 2. 5 1254 28 1218 29 1155 31 1107 32 1040 34 952 869 761
MED-LO 2. 0 1082 33 1051 34 1007 35 965 37 910 39 841 770 660
LOW 1. 5 889 40 872 41 829 43 815 44 765 46 711 659 585
HIGH 3. 0 1348 40 1283 42 1217 44 1151 46 1086 49 1014 931 844
MED 2. 5 1188 45 1139 47 1098 49 1039 51 986 54 916 834 758
MED-LO 2. 0 1015 53 985 54 945 56 909 59 858 62 804 733 655
LOW 1. 5 821 65 814 N/ A 788 N/ A 765 N/ A 720 N/ A 677 640 564
HIGH 4. 0 1736 41 1613 44 1578 45 1498 47 1409 50 1314 1226 1119
MED 3. 5 1657 43 1583 45 1501 47 1441 49 1366 52 1282 1173 1077
MED-LO 3. 0 1581 45 1510 47 1443 49 1371 52 1280 56 1199 1110 990
LOW 2. 5 1369 52 1313 54 1278 56 1225 58 1147 62 1071 990 888
HIGH 5. 0 2018 44 1953 46 1877 47 1788 50 1735 51 1659 1556 1448
MED 4. 0 1826 49 1749 51 1660 54 1566 57 1496 59 1415 1335 1220
MED-LO 3. 5 1618 55 1539 58 1476 60 1406 63 1340 66 1275 1194 1093
LOW 3. 0 1402 63 1354 66 1296 69 1242 N/ A 1173 N/ A 1108 1042 965
HIGH 5. 0 2123 50 2053 52 2000 53 1916 56 1832 58 1739 1646 1561
MED 4. 0 1912 56 1844 58 1770 60 1708 62 1619 66 1543 1436 1349
MED-LO 3. 5 1684 63 1622 66 1578 68 1503 71 1442 74 1374 1302 1204
LOW 3. 0 1493 71 1436 74 1371 N/ A 1319 N/ A 1264 N/ A 1208 1153 1061
0.3 0.4 0.50.1 0.2
*CSS960402BN
*CSS960603BN
*CSS960804CN
*CSS961005CN
*CSS961205DN
*MSS960603BN
*MSS960803BN
*MSS960804CN
*MSS960805CN
*MSS961005CN
*MSS961205DN
*MSS960402BN