Specifications
Page 16 • DRI-STEEM CRUV Electric Humidifier Installation, Operation, and Maintenance Manual
The steam outlet on the humidifier is sized to the output of 
the humidifier. DO NOT use vapor hose or interconnecting 
tubing/piping with an inside diameter smaller than the humidifier 
steam outlet. See note at left. 
•  See maximum steam carrying capacities in Table 16-1.
•  If the humidifier must be located higher then the dispersion 
assembly, use the recommend installation shown in Figure 15-1.
Connecting to humidifier with vapor hose
•  Support vapor hose to prevent sags, or low spots, and 
to maintain a minimum pitch of 2"/ft (15%) back to the 
humidifier.
•  Use DRI-STEEM vapor hose. Other manufacturers of vapor 
hose may use unacceptable release agents or material mixes 
that can affect humidifier system performance adversely. Using 
hose from alternative manufacturers increases the possibility of 
tank foaming and accelerated aging. Foaming causes condensate 
discharge at the dispersion assembly.
•  Do not use vapor hose in outdoor applications.
•  Do not insulate vapor hose. Insulation causes accelerated heat 
aging, causing the vapor hose to become hard and susceptible to 
failure due to cracks.
•  For single tube applications, see hose kit sizes in Table 19-1.
Table 16-1:
Maximum steam carrying capacity and length of interconnecting vapor hose, tubing and pipe*
Vapor hose Copper or stainless steel tubing and Schedule 40 steel pipe
Hose I.D. Maximum capacity Maximum length** Tube or pipe size***
Maximum
capacity
Maximum
developed length
†
inches DN lbs/hr kg/h ft m inches DN lbs/hr kg/h ft m
1½ 40 150 68 10 3 1½ 40 150 68 20 6.1
2 50 250 113 10 3 2 50 220 100 30 9.2
*  Based on total maximum pressure drop in hose, tubing or piping of 5" wc (1250 Pa)
**  Maximum recommended length for vapor hose is 10' (3 m). Longer distances can cause kinking or low spots.
***  To minimize loss of capacity and efficiency, insulate tubing and piping.
†  Developed length equals measured length plus 50% of measured length, to account for pipe fittings.
mc_051310_1200-NA
Important: 
Reducing the inside diameter of the 
interconnecting piping will result in the internal 
humidifier system pressure exceeding the 
parameters for acceptable performance.
mc_060210_0847
Important:
Failure to follow the recommendations in this 
section can result in excessive back pressure on 
the humidifier. This will result in unacceptable 
humidification system performance such as 
leaking gaskets, blown water seals, erratic water 
level control, and spitting condensate from the 
dispersion tube.
mc_060210_0843
Dispersion: 
Interconnecting piping requirements










