Measuring / calculating flow-rate

[45deg]

If I wanted to calculate the tonnage of a chiller's evaporator using the formula:

Tons = Delta_T x GPM / 24

How would I measure or calculate the GPM through the evaporator? I've been told to get it from the sales order for the chiller, but this would only give me what it is designed for and not the actual flow-rate.

 

[IRstuff]

Then, you need to go measure something, no? Presumably, something that measures velocity?

TTFN

FAQ731-376

 

[marcoh]

There are a numbed of ways to measure water flow. Most accurate method would be to install a magnetic flow meter in the pipework but if the installation is existing options include:

- Strap-on ultrasonic flow meter
- Measure pressure loss through evaporator and compare to design pressure loss
- Pressure loss through balancing valve
- Measure pump head and extrapolate from pump curve