Water Furnace IntelliZone2 MasterStat, Specification Catalog And Design Manual

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INTELLIZONE2 SPECIFICATION CATALOG
Peak Heating and Cooling Demands
Cooling-Dominated Structures
In cooling-dominated structures such as commercial
buildings and southern residential homes (where electric
heat is rarely needed as an auxiliary heat source), up to
five load calculations need to be performed. Commercial
hourly peak load calculations on all of the four zones
under control of the IntelliZone2 System are required. This
information sizes the supply air ductwork and the zone
damper properly. The fifth load is the entire building (all four
zones). Why perform this step? Because the different zones
have different times of day when they need peak cooling or
heating. The actual peak cooling or heating load is usually
less than the sum of the peak loads for the four zones.
The load calculation for the entire structure is used to size
the HVAC equipment only. Ductwork branches and zone
dampers are sized using the peak zone conditions for each
particular zone. The difference between the sum of the
peak loads for the individual zones and the peak load for
the entire building is called “diversity”.
Diversity is a measurement of the effective cooling or
heating capacity added to the system due to zoning. The
physical heating or cooling capacity is not increased,
but because it is more effective, HVAC equipment can
be sized smaller using zoning diversity. This represents
the first cost savings of the IntelliZone2 Comfort Zoning
System. Secondary savings are attributed to the lower
operating costs.
Many popular software packages or HVAC residential
loads now calculate peak zone loads; check your software
package for its capability.
Heating-Dominated Structures
In heating-dominated structures, such as northern
residential homes (where units are generally sized with
a small amount of electric heat installed as an auxiliary
heat source), diversity may be present in cooling; however,
the unit size is dictated by the heating load and diversity
is rarely present. In this application, a simple room-by-
room or zone-by-zone analysis can be performed with the
resultant sum of the rooms or zones taken as the whole
house load. The table below lists the four zone loads of this
example home.
NOTE: Dual Capacity 5 Series has a 70% low capacity
output, therefore minimum cfm required per zone is 40% of
nominal cfm.
Example Four Zone Load Summary
Htg
Btu/h
Htg
cfm Total
Clg
Sens
Clg
Clg
cfm
Max
cfm
Adjusted
100% cfm
Min cfm
Req’d.
Design
cfm
# of
Branch
Actual
cfm %
Actual
Load %
Zone
DIP %
Zone 1 Main Living
Kitchen 2259 73 3128 2400 145 145 118 1
Family 4264 138 6660 5128 311 311 252 2
Utility 3002 97 1614 1243 75 97 78 1
Living/Dining 6351 205 7158 5511 334 334 271 3
Total 15876 512 18560 14282 866 887 718 600 718 29% 34% 45%
Zone 2 Bedrooms
Bdrm 1 3224 104 1939 1752 106 106 240 2
Main Bath 892 29 284 407 25 65 147 1
Bdrm 2 2708 87 1692 1550 94 94 213 1
Total 6824 220 3915 3709 225 265 215 600 600 24% 15% 45%
Zone 3 Master Suite
Mstr Bdrm 2806 91 2294 1766 107 107 351 2
Mstr Bath 2350 76 1504 1158 70 76 249 1
Total 5156 166 3798 2924 177 183 148 600 600 24% 11% 45%
Zone 4 Basement
Total 19123 617 5007 3967 240 517 419 600 600 4 24% 41% 45%
Total Zones 46979 1515 31280 24882 1508 1852 1500 2518
Total House 46290 @ 70°F 32822 @ 20°F 123% 100% 168%
Unit Data
Nom Hi cfm Min Lo cfm 40% Nom cfm
Model
ND*049 1500 1350 600