just wanted to know if this was a proper way to do a basic btu test? thanks
I have attached the BTU test sheet for a 1-ton chiller. Please note the bottom right corner for a place to keep the temperature for each minute. The instructions for the test are as follows:
1) You must have the exact volume of water contained within the chiller and system. It would be easiest to calculate this volume if you can tie the input and output lines together that run to the air handler. Or, you must empty the system and measure the amount of water exactly to the gallon that you add to fill the system completely.
2) Allow the water to heat up and stabilize to around 90-95 degrees F either by allowing the pump to run without the compressor kicking on or cut the thermostat of the chiller up to 90-95 degrees to allow the water to get that hot and once it reaches 90-95 then set the chiller thermostat down to 45 degrees and when the compressor kicks on allow a few moments for the refrigerant to flow and the unit to begin working. When the temperature begins to drop start timing and start recording the temperature.
3) Measure and record the temperature of the water each minute for 10-15 minutes. After the 10 or 15 minutes stop the refrigerated part of the chiller but leave the pump on and write the temperature down. Monitor the temperature and if it drops any further then use this as a final temperature.
4) Take the total volume of water(in gallons) and multiply it by 8.34 to give you the total weight of water in lbs.
5) Take the total weight of water in lbs. and multiply it by the total difference(starting temp vs final temp) in temperature measured on the water from step #3.
6) Take the number you get from the calculation in step #5 and multiply it by 6(if you measured water temp for 10 mins) or by 4(if you measured the water temp for 15 mins) to give you the total BTUs.