28c System Sizing for Commercial Applications
A 28c multi-unit system can produce up to 5,235 gallons per hour at a 77-degree rise. The 28c System for commercial applications is sized to meet Peak Demand just like a home system. The calculation is simple, based on the BTUs required to raise your required flow up to usage temperature.

	•	First, calculate the Peak Demand in Gallons Per Minute.
	•	Second, estimate the incoming water temperature at the most demanding point in the year, usually January (unless, of course, you are designing a system for a summer camp!). Your water utility company is a good source for this information.
	•	Third, establish the usage temperature for each major use. It does not matter in the calculation if you establish different temperatures for different uses.
	•	Fourth, calculate the BTUs needed to generate this supply of hot water.
	•	Finally, add these up for each usage and divide by 199,900 (the BTUs of the 28-C) to estimate the number of units you need in your system.
	•	Smart energy use - Just like a tankless system for home use, commercial applications can also leverage the Paloma's "on-demand" energy-wise performance.

The Paloma Commercial Sizing Calculator downloadable from this page is an Excel-based tool to help you with these sizing calculations. Alternatively, if you are replacing a storage system where you know the hourly output, you can use the hourly output (Gallons Per Hour) based on the appropriate temperature rise.

The Sizing Reference Table

Peak Output (GPM) Gallons Per Hours (GPH) Units in System 45-degree rise 70-degree rise 100-degree rise 45-degree rise 70-degree rise 100-degree rise 1 7.4 4.8 3.4 444 288 204 2 14.8 9.6 6.8 888 576 408 3 22.2 14.4 10.2 1,332 864 612 4 29.6 19.2 13.6 1,776 1,152 816 5 37.0 24.0 17.0 2,220 1,440 1,020 6 44.4 28.8 20.4 2,664 1,728 1,224 7 51.8 33.6 23.8 3,108 2,016 1,428 8 59.2 38.4 27.2 3,552 2,304 1,632 9 66.6 43.2 30.6 3,996 2,592 1,836 10 74.0 48.0 34.0 4,440 2,880 2,040 11 81.4 52.8 37.4 4,884 3,168 2,244 12 88.8 57.6 40.8 5,328 3,456 2,448 13 96.2 62.4 44.2 5,772 3,744 2,652 14 103.6 67.2 47.6 6,216 4,032 2,856 15 111.0 72.0 51.0 6,660 4,320 3,060 16 118.4 76.8 54.4 7,104 4,608 3,264 17 125.8 81.6 57.8 7,548 4,896 3,468 18 133.2 86.4 61.2 7,992 5,184 3,672 19 140.6 91.2 64.6 8,436 5,472 3,876 20 148.0 96.0 68.0 8,880 5,760 4,080