Aprilaire 800 Installation Instructions, Elevation, Distance from Humidifier to Dispersion Tube

INSTALLATION INSTRUCTIONS (continued)

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.	Pitch*
90° long sweep
or two 45° elbows	Duct

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	Pitch

*Pitch steam hose down from dispersion tube to humidifier:

2"/ft (15%) minimum when using steam hose.

1/4"/ft when using hard pipe.

90-1521

Insulate hard pipe to

reduce steam loss

To

Dispersion

Tube

6" min

8" min

1" air gap

Open drain required,

see note 1.

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.

90-1520

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	120 Volts		208 Volts		240 Volts
or Insulated
	Steam Hose	Insulated Pipe	Steam Hose	Insulated Pipe	Steam Hose	Insulated Pipe
Pipe Length
< 2 ft..	11..5	11..5	20..5	20..5	23..3	23..3
2 ft..	11	11	20	20	23	23
4 ft..	10	11	19	20	22	23
6 ft..	9	11	18	20	21	22
8 ft..		10		19		22
10 ft..		10		19		22
12 ft..		10		19		22
14 ft..		9		18		21
16 ft..		9		18		21
18 ft..		9		18		21
20 ft..		9		18		20

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