Aprilaire 800 Installation & Maintenance Instructions Manual page 6

InSTallaTIon InSTRUCTIonS
elevation
The preferred location for the dispersion tube is higher than the humidifier so that the steam hose has a constant downward slope of at least 2"
per foot from the dispersion tube to the humidifier . If hard pipe is used, the slope can be 1/4" per foot . With the constant downward slope, any
condensation that forms in the steam hose will drain back into the steam canister . See figure 3 . If the dispersion tube must be mounted below the
humidifier or if the steam hose needs to run up and over an obstruction, a drip tee with drain trap must be installed as shown in figure 4 .
fIGURe 3 – Dispersion Tube Mounted above Humidifier
Steam hose or pipe.
Insulate pipe with
Dispersion tube
1" fiberglass to
reduce steam loss.
90° long sweep
or two 45° elbows
*Pitch steam hose down from dispersion tube to humidifier:
2"/ft (15%) minimum when using steam hose.
1/4"/ft when using hard pipe.
Distance from Humidifier to Dispersion Tube
The capacity of the humidifier is reduced by the length of the steam hose or pipe due to condensation . The maximum recommended length
of steam hose is 6 feet . Use hard pipe insulated with 1" fiberglass for lengths greater than 6 feet . Table 3 provides humidifier capacity with
various lengths of steam hose and pipe . If 6-foot steam hose does not reach from humidifier to dispersion tube, splice in 1" copper pipe using
¾" x 1" reducing couplings as shown in figure 5 .
Table 3 – Steam Humidifier Capacity in Gallons/Day
Steam Hose
or Insulated
Steam Hose
Pipe length
< 2 ft . 11 .5
2 ft . 11
4 ft . 10
6 ft . 9
8 ft .
10 ft .
12 ft .
14 ft .
16 ft .
18 ft .
20 ft .
6
(ConTInUeD)
Duct
90-1521
120 Volts
Insulated Pipe Steam Hose
11 .5
11
11
11
10
10
10
9
9
9
9
fIGURe 4 – Dispersion Tube Mounted below Humidifier
Drip tee installation for piping over obstruction,
or if dispersion tube is lower than humidifier.
90° long sweep
or two 45° elbows
Insulate hard pipe to
reduce steam loss
6" min
8" min
1" air gap
Open drain
required,
see note 1.
208 Volts
Insulated Pipe
20 .5 20 .5
20 20
19 20
18 20
19
19
19
18
18
18
18
Obstruction
Drip tee
Drain trap
NOTES:
1. Refer to governing codes for
drain pipe size and materials.
2. Support steam hose so there
are no sags or low spots.
240 Volts
Steam Hose Insulated Pipe
23 .3 23 .3
23 23
22 23
21 22
22
22
22
21
21
21
20
90-1520