METHOD C: COMMERCIAL
1) Table 3 shows demands for various fixtures found in commercial buildings in gallons per hour. To
determine the hot requirements of the building:
a) Using Worksheet 2, determine and record the total number of each type of fixture in the building
under column (2).
b) Use Table 3 to find the number of gallons of 135F water used per hour. Record this value per fixture in
column (1). Hourly usage of some commercial kitchen fixtures is shown in Worksheet 2.
c) Multiply each line in column (1) by the number in column (2). The result is the total amount of
water used for each type of fixture per hour. Record this in column (3).
d) Total column (3). The result is the total amount of water used by all fixtures per hour. This is the
POSSIBLE MAXIMUM DEMAND.
e) The demand factor shown in line 12 of Table 3 is intended to take into consideration the fact that
not all fixtures will be in use at the same time. Multiply the total demand calculated in step (d) by
this factor. The result is the PROBABLE MAXIMUM DEMAND.
f)
If a commercial dishwasher or laundry is on the job, determine the maximum amount of 135F water,
which could be used in the hour. This will depend upon the number of machines, the amount of
water used per machine, and usage pattern. Consult the machine manufacturer and the building
owner for this information. Once the maximum hourly usage is known for this equipment, enter it
in the spaces provided under Column (3).
g) Add the hourly usage for dishwasher and washing machines to the Probable Maximum Demand.
This is the ADJUSTED PROBABLE MAXIMUM DEMAND.
2) Select the Maxi-Therm:
a) If a boiler is to be installed with the Maxi-Therm:
•
Go to Table 1 and select a Maxi-Therm with a 135F First Hour Rating greater than or equal to
the Adjusted Probable Maximum Demand calculated in (1g).
•
Use the appropriate graph in Figures 4a-4d to determine the boiler output needed to generate
the required First Hour Rating.
•
Determine the boiler required to satisfy the space-heating requirement alone.
•
Install the Maxi-Therm with a boiler having the larger of the above two outputs.
b) If the Maxi-Therm is to be installed with an existing boiler:
•
Go to Table 1 and select a Maxi-Therm which has a 135F First Hour Rating greater than or
equal to the Adjusted Probable Maximum Demand calculated in (1g).
•
Use the appropriate graph in Figures 4a-4d to find the First Hour Rating that can be expected
with the boiler on the job.
•
If this First Hour Rating is unacceptable, the boiler on the job is too small. Depending on the
hot water usage pattern, the use of a larger Maxi-Therm may compensate for the undersized
boiler. Consult a Crown Representative for additional guidance.
9
Содержание MAXI-THERM MT040G
Страница 4: ...3 Figure 1b MT079G and MT100G General Configuration Figure 1a MT040G and MT050G General Configuration...
Страница 22: ...Figure 6 Boiler Side Piping Using Circulator Zones Figure 7 Boiler Side Piping Using Zone Valves 2 Way 21...
Страница 28: ...Figure 12 Basic Domestic Side Piping Figure 13 Domestic Side Piping Using a Mixing Valve 27...
Страница 30: ...Figure 15 Domestic Side Piping for Multiple Maxi Therms 29...
Страница 32: ...Figure 16 Non Priority Circulator Zoning Using Honeywell R845a s Figure17 PriorityCirculatorZoning 31...
