| COP |
= |
EER ÷ 3.413 |
| COP |
= |
SEER × 0.9 ÷ 3.413 |
| COP |
= |
12 ÷ (3.413 × kW/ton) |
|
|
| kW/ton |
= |
12 ÷ (COP × 3.413) |
| kW/ton |
= |
12 ÷ EER |
| kW/ton |
= |
12 ÷ (SEER × 0.9) |
|
| |
|
|
| EER |
= |
COP × 3.413 |
| EER |
= |
12 ÷ kW/ton |
| EER |
= |
SEER × 0.9 |
|
|
| SEER |
= |
COP × 3.413 ÷ 0.9 |
| SEER |
= |
12 ÷ (kW/ton × 0.9) |
| SEER |
= |
EER ÷ 0.9 |
|
|
| |
| |
| Handy Formulas Every Engineer Should Know |
| |
| WATER |
| TONS |
= |
| GPM × (EWT - LWT) |
 |
| 24 |
|
| or... TONS |
= |
| 500 x GPM x (EWT-LWT) |
|
| 12000 |
|
| PUMP BHP |
= |
| GPM x Total System Head (ft w.g.) |
|
| 3960 x PUMP Effic |
|
| WATER PRESSURE DROP (Ft) |
= |
2.31 x Psig |
|
| |
| AIR |
| TOTAL COOLING LOAD (Btu/h) |
= |
4.5 × CFM STANDARD AIR × (h1 - h2) |
| SENSIBLE COOLING LOAD (Btu/h) |
= |
1.08 × CFM STANDARD AIR × (Tdb1 - Tdb2) |
|
| |
| ELECTRICAL |
| PUMP KW |
= |
| GPM × Pressure drop (ft) |
|
| 5311 × Eff pump × Eff motor |
|
| FAN HP |
= |
| CFM × Static pressure (") |
|
| 6350 × Eff fan |
|
|
| |
| BASIC FAN LAWS |
| CFM1/CFM2 |
= |
RPM1/RPM2 |
|
|
| SP1/SP2 |
= |
(RPM1/RPM2)² |
= |
(CFM1/CFM2)² |
| BHP1/BHP2 |
= |
(RPM1/RPM2)³ |
= |
(CFM1/CFM2)³ |
|
| |
| DRIVE CALCULATIONS |
| MOTOR RPM × MOTOR PULLEY PD |
= |
BLOWER RPM × BLOWER PULLEY PD |
|
| |
| This information is provided for your convenience. We feel it's reliable, but errors can occur. We make no claims as to the accuracy of this information and do not warrant it for any use or purpose whatsoever. Always verify specification data in order to ensure its accuracy. |
|
