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II - 4
Design of W-ECO MULTI SYSTEM
2
TD831077
1-3. Calculation of actual capacity
Since the capacity of multi air-conditioner changes according to the temperature conditions, tubing length, elevation
difference, etc. select the right model taking into account various correction values.
7
The actual capacity of multi air-conditioner according to its installation conditions is given by the
following expression.
<Cooling capacity>
Cooling capacity of indoor unit = (Indoor unit corrected capacity by indoor / outdoor capacity ratio)
×
1
(P. II-6)
(Capacity coefficient by indoor / outdoor temperature conditions)
×
2
(P. II-8 (For R407C), II-10 (For R22))
(Capacity coefficient by tubing length)
3
(P. II-9 (For R407C), II-11 (For R22))
<Heating capacity>
Heating capacity of indoor unit = (Indoor unit corrected capacity by indoor / outdoor capacity ratio)
×
1
(P. II-6)
(Capacity coefficient by indoor / outdoor temperature conditions)
×
2
(P. II-8 (For R407C), II-10 (For R22))
(Capacity coefficient by tubing length)
×
3
(P. II-9 (For R407C), II-11 (For R22))
(Capacity coefficient by frosting / defrosting)
4
(P. II-8 (For R407C), II-10 (For R22))
* There is a respective characteristics chart on the page written below each correction item. Find out the respective
correction values from various conditions.
7
Capacity correction by indoor / outdoor capacity ratio of indoor unit :
1
1
1
1
1
The total capacity ratio of indoor unit as against the outdoor unit can be connected maximum up to 130 %.
If the usage time period changes, or in case of buildings where the generating time of maximum load changes, the
capacity of outdoor unit can be reduced by selecting somewhat larger total capacity of the indoor units than that of the
outdoor unit. Here, if the indoor/outdoor capacity ratio exceeds 100 %, the capacity of outdoor unit increases somewhat
during concurrent operation, but the capacity of each indoor units decreases below the rated value.
The corrected capacity of indoor unit can be found out from the table of corrected capacities given on P. II-6, after
calculating the indoor / outdoor capacity ratio with the following expression, separately for cooling and heating.
• Cooling :
* Indoor / Outdoor unit capacity ratio =
(Total cooling capacity of indoor units)
×
100
(Rated capacity of outdoor unit)
• Heating :
* Indoor / Outdoor unit capacity ratio =
(Total cooling capacity of indoor units)
×
100
(Rated capacity of outdoor unit)
1. Model Selecting and Capacity Calculation