Selection Chart for Water Heaters Without Storage Tanks
but with Forced Return Line Circulating Pump
*Usage adjustment factors - heaters deliver required BTUs
over 3-hour period.
- System without return circulation.........multiply # of apts. by 1.2
- Apartments with 1 1/2 baths.........multiply # of apts. by 1.2
- Apartments with 2 baths........multiply # of apts. by 1.3
- Apartments with one whirlpool bath........multiply # of apts. by 1.25
- Apartments with individual washing machines........multiply # of apts. by 1.2
Number of
Units
|
2-3 GPM
40 Inlet
|
2-3 GPM
60 Inlet
|
4-5 GPM
40 Inlet
|
4-5 GPM
60 Inlet
|
|
< 4
|
75T75
|
75T75
|
75T75
|
75T75
|
|
4-6
|
75T75
|
75T75
|
75T125
|
75T125
|
|
7-8
|
75T125
|
75T125
|
75T125
|
75T125
|
|
9-10
|
80T180
|
80T180
|
80T180
|
80T180
|
|
11-15
|
80T199
|
80T180
|
80T199
|
80T180
|
|
16-20
|
(2) 75T125
Or
(1) 80T250
|
80T250
|
(2) 80T180
Or
(1) 68T370
|
(2) 80T199
Or
(1) 80T399
|
|
21-30
|
(2) 80T199
Or
(1) 80L399
|
(2) 80T180
Or
(1) 65T370
|
(2) 80T250
Or
(1) 80L505
|
(2) 80T180
Or
(1) 80L505
|
|
31-40
|
(2) 100T199
Or
(1) 80L505
|
(2) 80L180
Or
(1) 80L399
|
(3) 80T180
Or
(2) 65T370
|
(2) 100T199
Or
(1) 80L505
|
|
41-50
|
(3) 80T180
Or
(1) 80L505
|
(2) 80T180
Or
(2) 80L360
|
(2) 80T250
Or
(1) 80L505
|
(2) 80T180
Or
(1) 80L505
|
|
51-75
|
(3) 100T199
Or
(1) 80T725
|
(3) 80T 180
Or
(1) 80L505
|
(2) 80L505
Or
(3) 65T370
|
(2) 65T370
Or
(3) 100T199
|
|
76-100
|
(2) 80L399
|
(2) 80T199
Or
(2) 75T300
|
(2) 80T725
Or
(3) 80L399
|
(3) 75T 300
Or
(2) 80L505
|
When more than one correction factor is applicable, add the
decimal portion of the individual factors to 1 and multiply
the new total by the number of units.
