Coil Selection Calculator
Instructions:
Review the methodology to ensure it aligns with your project's requirements.
BTUH Capacity & Leaving Air Temperature
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Select US or Metric Units
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Sensible Cooling:
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Select the parameter for which to solve: Sensible Cooling, Volume Flow Rate, Leaving air Temperature, or Entering Air Temperature.
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Enter all of the required inputs.
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Click the Calculate button, and the Result will show below the table.
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Total Cooling:
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Select the parameter for which to solve: Total Cooling, Volume Flow Rate, Leave air Enthalpy, or Entering Air Enthalpy (note there is a Calculate Enthalpy button to take you to our Psychrometric Calculator to solve for Enthalpy).
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Enter all of the required inputs.
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Click the Calculate button, and the Result will show below the table.
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Latent Cooling
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Select the parameter for which to solve: Latent Cooling, Volume Flow Rate, Leave air Humidity Ratio, or Entering Air Humidity Ratio (note there is a Calculate Humidity Ratio button which will take you to our Psychrometric Calculator to solve for Humidity Ratio).
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Enter all of the required inputs.
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Click the Calculate button, and the Result will show below the table.
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Area & Velocity
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Select US or Metric Units
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Enter the fin length and height
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Enter the flow rate
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Click the calculate button, and the Results will show below the table.
Water and Glycol Flow
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Select US or Metric Units
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Select the parameter for which to solve: Fluid Capacity, Volume Flow Rate, Entering Temperature, or Leaving Temperature.
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Enter all of the required inputs.
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Click the calculate button, and the Result will show below the table.
Water Velocity
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Select US or Metric Units
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Enter flow rate, tube diameter, and number of tubes.
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Click the calculate button, and the Result will show below the table.
Methodology and Equations :
BTUH Capacity & Leaving Air Temperature
The following equations are used in this calculator:
Sensible Cooling [BTU/h] = CFM x 1.0746 x (T1 – T2)
Latent Cooling [Btu/h] = CFM x 0.69143 x (G1 – G2)
Total Cooling [Btu/h] = CFM x 4.5 (H1 – H2)
where
CFM = volume flow rate [cfm]
G1= Entering humidity ratio [grains,moisture/lb,dry air]
G2 = Leaving humidity ratio [grains,moisture/lb,dry air]
H1 = Entering enthalpy [BTU/lb, dry air]
H2 = Leaving enthalpy [BTU/lb, dry air]
T1 = Entering air temperature [oF]
T2 = Leaving air temperature [oF]
Area & Velocity
The following equations are used in this calculator:
Coil area [ft] = Fin height x Fin length / 144 in^2/ft^2
Air Velocity = CFM / FPM
where
CFM = volume flow rate of air [cfm]
FPM = velocity of air [fpm]
Water and Glycol Flow
The following equation is used in this calculator:
Fluid capacity [BTU/h] = rho x cp x (T1 - T2) x [GPM] x 60 min/hr
where
rho = fluid density [lb/gallon]
cp = specific heat of fluid [Btu/lb-oF]
T1 = Entering fluid temperature [oF]
T2 = Leaving fluid temperature [oF]
GPM = Volume flow rate [GPM]
Water Velocity
The following equations are used in this calculator:
V = Q x C / ID^2 / No. of Tubes
where
C = English Unit Conversion Constant = 0.408498
ID = Tubing Inner Diameter [in]
Q = flow rate [GPM]
V = velocity [f/s]