Calculators.

General
  Unit Conversion
  Periodic Table
  Gas properties
HVAC
  Heating piping
  Psychrometrics
Piping
  Darcy Weisbach
  Water Hammer
Industrial
  Tank volume
  Pressure Vessel
Electrical
  Voltage Drop
  kVAR calculator
  Motor protection
  Motor sizing

This Little program calculates the necessary water flow (in m3/h) to transfer heating or cooling energy (in kcal/h and btu/h respectively) for a given temperature difference.  You may also calculate (if you enter the flow rate) the heat/cool transfer capacity of the given flow rate (for the given temperature difference of course).

Then , the program will calculate velocity , and by clicking the calculate button the energy loss in the pipe ,using the popular Darcy-Weisbach equation :
 h_f = f * ( L / D) * (V² / 2 * g). 

In order to calculate the minor losses (fittings) you must add the corresponding Km values from the table below , and enter them in the Km textbox  of applet.

Fitting	Km
Globe valve, fully open	10.00
Angle valve, fully open	2.00
Gate valve, fully open	0.15
Gate valve, 1/2 closed	2.10
Swing check valve , flow	2.00
Elbow 90o - flanged	0.30
Elbow 90o - threaded	1.50
Long radius 90°, flanged	0.20
Long radius 90°, threaded	0.70
Elbow 45°, threaded	0.40
Tee , Line flow, flanged	0.20
Tee , Line flow, threaded	0.90
Tee , Branch flow, flanged	1.00
Tee , Branch flow, threaded	2.00
Piping Entry & Exit	1.00

The value of  friction factor f is calculated using the colebrook equation , and can be checked using the Moody diagram.

 

Before you use the program , you should read the following:

1. The water properties (viscosity , density and c_p) for heating are calculated for 90^oC temperature (1bar).
2. The water properties (viscosity , density and c_p) for cooling are calculated for 5^oC temperature (1bar).
3. Generally the program provides a very good approximation for different temperatures or pressure NEAR these values.

Below is given a general diagram to explain the use of the program.

    Before using the calculators
    please read the Copyright and Disclaimer Notice.

Optimized for 1024x768 Screen view.   Last Update 14/01/2002 .