Final answer:
When manufacturers' specifications are not available, a good way to calculate cubic feet per minute (CFM) through a coil is to measure the coil's dimensions and use a CFM calculator. This method involves multiplying the length, width, and height of the coil to calculate its volume, which can then be used to determine the CFM based on the desired air change rate per minute.
Step-by-step explanation:
When manufacturers' specifications are not available, a good way to calculate cubic feet per minute (CFM) through a coil is to measure the coil's dimensions and use a CFM calculator. This involves measuring the coil's length, width, and height, and inputting those values into a formula or online calculator that determines the CFM based on the dimensions.
For example, if the coil has a length of 2 feet, width of 1.5 feet, and height of 1 foot, you would multiply these dimensions together to get the coil's volume (2 x 1.5 x 1 = 3 cubic feet). Then, you can use this volume to calculate the CFM by dividing it by the desired air change rate per minute.
It's important to note that this method is an estimation and may not be as accurate as using manufacturers' specifications or consulting HVAC professionals. However, it can provide a reasonable approximation in situations where those options are not available.