Approved NEBB - Page 1 of 8 Version 1.

1 A = Area (ft ) IP, (m ) SI M = Mass (lb) IP, (kg) SI ACH = Air Changes per Hour ma = Mixed Air Ak = Effective Area m = meter (metre) AV = Average m /s = Volumetric Flow: Cubic Meters Per Second BHP = Brake Horsepower (IP) HP NLA = No Load Amperage BP = Brake Power (SI) kW NPSHA = Net Positive Suction Head Available Btu = British Thermal Unit oa = Outside Air Btu/h = Btuh = BTUH = BTU/Hour % oa = % of Outside Air = Center Distance (used in belt formula) = Ohm C = Degrees Celsius, C P = Pressure C = Friction Loss Coefficient (For Duct Fittings) Pa = Atmospheric Pressure CCF = 100 Cubic Feet Pab = Absolute Pressure (Atmospheric Pressure + Gauge Pressure) CFM = Volumetric Flow: Cubic Feet Per Minute Pa = Pascals, Pressure SI Cp = Specific Heat = Cv = Flow Constant (IP) PD = Sheave Pitch Diameter = Density (lb/ft ) IP, (kg/m ) SI P = Pressure at Pump Centerline d = Diameter (in.)

2 IP, (mm) SI ppm = parts per million = Difference or Change (Final - Initial) psi = Pounds Per Square Inch dimp = Impeller Diameter psia = Pounds Per Square Inch Absolute E = Volts psig = Pounds Per Square Inch Gauge Eff = Efficiency Pvp = Absolute Vapor Pressure EP = Pump Efficiency Q (flow) = Volumetric Fluid Flow Rate: ( CFM, GPM, m /s, l/s, etc.) F = Degrees Fahrenheit, F Q (heat) = Heat Flow Rate (BTU/Hour) IP, (W or kW) SI f = Friction Factor R = Rankin = Degrees Rankin, R FLA = Full Load Amps r = Radius (in) IP, (mm) SI fpm = Feet per Minute (fpm) % ra = % of Return Air ft = Foot R = Resistance g = Acceleration of Gravity ra = Return Air gal = Gallons rad = Radians GPM = Gallons Per Minute (GPM) RH = Relative Humidity h = Enthalpy (BTU/lb dry air) IP, (kJ/kg dry air) SI RPM = Revolutions Per Minute H = Head (in wc, ft wc, psi) IP, (Pa, kPa) SI Rvalue = Thermal Resistance Hg = Mercury s = second hma = Mixed Air Enthalpy SHR = Sensible Heat Ratio hoa = Outside Air Enthalpy SME = Sash Movement Effect Performance Rating (SME-XX yyy) HP = Horsepower SP = Static Pressure hr = Hour Sp Gr = Specific Gravity (for water use ) hra = Return Air Enthalpy T = Temperature HT = Height (in) IP, (mm)

3 SI Ta = Absolute Temperature (460 + T) or R I = Amps Tma = Mixed Air Temperature J = Joules Toa = Outside Air Temperature K = Kelvin, K TP = Total Pressure Kv = Flow constant (SI) Tra = Return Air Temperature kg = Kilogram TS = Tip Speed (fpm) IP, (m/s) SI kJ = Kilojoule U = Heat Transfer Coefficient kPa = Kilopascal = viscosity, dynamic kW = Kilowatt = 1000 Watts V = Velocity l = Liter (Litre)VP = Velocity Pressure l/s = Volumetric Flow: Liters Per Second W = Watt lb = Pounds WD = Width (in) IP, (mm) SI lm = Lumens wg = wc = water gauge = water column ln = natural log WHP = Water Horsepower (IP) LG = Length (in) IP, (mm) SI WP = Water Power (SI) lx = Lux = Humidity Ratio (lb or grains of water/lb of dry air) (g H2O/kg dry air) NEBB Fundamental FormulasApproved NEBB - January 11, 2018 Page 1 of 8 Version & Velocity Equations Q V A Q V x A TP VP SP TP VP SP V 4005 VP V VP V 1096 VP V VP ACH Q 60 LG x WD x HT ACH Q 3600 LG x WD x HT Area d2 144 r 144 Area d2 1,000,000 r 1,000,000 Area / HT WD 144 Area / HT WD 1,000,000 Area HT x WD - HT 2HT 144 Area HT (WD - HT 2HT 1,000.)

4 000 Air Temperature Equations 32 32 R 460 K 273 T % T % T h % h % h % T T T T 100% h h h h 100 Heat Transfer Calculations Q CFM h Q ls hQ 60 Cp CFM T Q Cp ls T Q CFM T Q ls T Q CFM Q ls Q 4840 CFM SHR Q Q Q Q Q Q A U Q A U Fan EquationsCFM CFM RPM RPM ls ls m s m s rads rads P P CFM CFM P P ls ls m s m s BHP BHP CFM CFM kW kW ls ls m s m s Tip Speed TS d rpm 12 Tip Speed TS d rpm 60 NEBB Fundamental FormulasApproved NEBB - January 11, 2018 Page 2 of 8 Version Equations RPM PD PD RPM RPM RPM PD PD Fan Belt Length 2 PD PD PD PD 4 Electrical Equations Power E I 1 kW 1000 Watts I E E I 1 HP 746 Watts 1 Watt Btu/hr Power Equations BHP E I PF Eff 746PF Power Factor kW E I PF 1000PF Power Factor BHP E I PF Eff 746 PF Power Factor & Eff.

5 If not given kW E I PF 1000 BHP HP I NLA FLA NLA FLA FLA E E Fan HP CFM TP SpGr 6356 Eff Resistance Series Circuit: total resistance: R Parallel Circuit: total resistance: R R R R R R 1R 1R 1R 1R E I E I Voltage Drop I R Conversionskilowatts Kw Btu / hr 3413 horsepower HP Btu / hr 2545 joules Btu / hr kilogram calories Btu / hr tons of cooling chiller Btu / hr 12000 tons of cooling cooling tower Btu / hr 15000 gallons water pounds lb. millimeters inches centimeters inches bar pounds per square inch PSI inches of water pounds per square inch PSI inches of Mercury Hg pounds per square inch PSI NEBB Fundamental FormulasApproved NEBB - January 11, 2018 Page 3 of 8 Version Pump EquationsGPM GPM RPM RPM ls ls m s m s rads rads GPM GPM d d m s m s d d H H GPM GPM H H m h m h rads rads BHP BHP GPM GPM BP BP m s m s rads rads WHP GPM H SpGr 3960 SpGr ,unless given,EP use if not givenWP m s H SpGrWP ls H SpGr 1002 BHP GPM H SpGr 3960 EP SpGr ,unless given,EP use if not given BP WPEPEP % WHP 100 BHPEP % WP 100 BPHydronic Calculations Coil P: GPM GPM P P Coil P.

6 M h m h P P C GPM SpGr P K m h SpGr P GPM C P SpGrSpGr ,unless given,EP use if not given m h C P SpGrSpGr ,unless given,EP use if not given P SpGr GPMC SpGr ,unless given,EP use if not given P SpGr m h K SpGr ,unless given,EP use if not given NPSHA P P V 2g P P Heat Transfer Calculations 500 4190 4190 Boiler Calculations Output Btu Input Btu %Eff Fire Rate Input BtuFuel Btu Boiler Operating Cost Fire Rate hrs Burned $Costgal Btu lb of water 500 T NEBB Fundamental FormulasApproved NEBB - January 11, 2018 Page 4 of 8 Version Equivalents acceleration m/s2meters per second squared1m/s2 ft/sec2airflow volumetric flow rate m3/s cubic meters per second1 m3/s cfm l/sliters per second1 l/s cfmm3/hr cubic meters per hour1 m3/hr cfmarea m2square meter1 m2 ft2mm2square millimeters1 mm2 in2atmospheric pressure kPa in Hg psiBarBarometers1 Bar 100kPa in Hg psidistance.

7 Length, or distance mmeter1 m ftmmeter1 m inmmmillimeter1 mm inlighting intensity lxLux1 lx fclm/m2 Lumens/square meter1lm/m2 fcpressure kPakiloPascals 1000 Pascals1 kPa in Hg psiPaPascals1 Pa in wgtemperature Cdegrees Celsius C F 32 / m/smeters per second1 m/s fpmvolume m3cubic meters1 m3 ft31 Btu Energy required to heat 1 lb of H2O from 39 F to 40 F 1 CCF 100000 Btu 1 ft inches 12 1 ft wc psi 1 ft Hg psi inches ft x 12 1 mm Hg in wc 1 in Hg ft 1 kW/hr 3413 Btu 1 lb moisture 7000 grains 1 psi ft wc 1 psi in wc 1 psi in Hg 1 Ton refrigeration 12000 Btu/hr Atmospheric. Press in Hg or psi Density of Air Std lb/ft3 Density of Water Std lb/ft3 or gal/ft3 or lb/gal One foot of mercury Hg column lb/in2 psi One inch of mercury Hg column inches in wg ft wg Specific Heat Cp of dry air Btu/lb x F @ 68 F Specific Heat Cp ice Btu/lb x F @ 68 F Specific Heat Cp vapor Btu/lb x F @ 68 F Specific Heat Cp water Btu/lb x F @ 68 F Specific Volume of Air Std ft3/lb NEBB Fundamental FormulasApproved NEBB - January 11.

8 2018 Page 5 of 8 Version 100 105 110 115 120 125 130 DRY BULB TEMPERATURE - F102030405060708090100110120130140150160 1701801902002101015202530354045505555606 06570 ENTHALPY - BTU PER POUND OF DRY AIR05101520253035404550 ENTHALPY - BTU PER POUND OF DRY AIRSATURATION TEMPERATURE - F-50 0551010151520202525303035354040454550505 5556060656570707575808085 WET BULB TEMPERATURE - F859015%25%2%4%6%8%10% RELATIVE HUMIDITY20%30%40%50%60%70%80%90% SPECIFIC VOLUME ft /lb OF DRY RATIO - GRAINS OF MOISTURE PER POUND OF DRY AIRPSYCHROMETRIC CHARTBAROMETRIC PRESSURE inches of MercuryLinric Company Psychrometric Chart, .1 .2 .3 .4 .5 .6 .7 .8 .9 1 PRESSURE - INCHES OF MERCURY-20 0 10 20 25 30 35 40 45 50 55 60 65 70 75 80 85 DEW POINT - HEATQsTOTAL HEATQt ENTHALPYHUMIDITY RATIOhWNEBB Fundamental FormulasApproved NEBB - January 11, 2018 Page 6 of 8 Version BULB TEMPERATURE - C-30-20-10010203040506070809010011012013 0140150150160160170170180180 ENTHALPY - KJ PER KILOGRAM OF DRY AIR-30-20-100102030405060708090100110120 130140 ENTHALPY - KJ PER KILOGRAM OF DRY PRESSURE - MM OF MERCURY-10-5 0 5 10 15 20 25 30 35 DEW POINT TEMPERATURE - HEAT RATIO = Qs / QtSENSIBLE HEAT RATIO = Qs / Qt24681012141618202224262830323436384015 %25%2%4%6%8% RELATIVE HUMIDITY10% RELATIVE HUMIDITY20%30%40%50%60%70%80%90%-30-25-2 0-15-15-10-10-5-5 0551010151520202525303035 WET BULB TEMPERATURE - VOLUME - CUBIC METER PER KG DRY RATIO - GRAMS MOISTURE PER KILOGRAM DRY HEATQsTOTAL HEATQt ENTHALPYHUMIDITY RATIOhW-35-30-25-20-15-10-PSYCHROMETRIC CHARTPSYCHROMETRIC CHART - METRICNORMAL TEMPERATURENORMAL TEMPERATURESI UnitsSI UnitsSEA LEVELSEA LEVELBAROMETRIC PRESSURE: kPaBAROMETRIC PRESSURE.

9 KPaNEBB Fundamental FormulasApproved NEBB - January 11, 2018 Page 7 of 8 Version 150 200 250 300 340 121 Water Temperature FFeet head differential per inch Hg differentialAir Density Correction Factors (US Units) Standard Air Density (Sea Level & 70 F) = lb/ft3 @ in HgAir Temperature FAltitude (ft)(in wg)Barometer (in Hg)Water Temperature CAir Density Correction Factors (Metric Units) Standard Air Density (Sea Level & 20 C) = kg/m3 @ kPaAltitude (m)Barometer (kPa)Air Temperature CNEBB Fundamental FormulasApproved NEBB - January 11, 2018 Page 8 of 8 Version