Test Water Conductivity Prior to Selecting & Installing a Steam Humidifier

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Installing a steam humidifier can be one of the most effective ways of increasing the humidity in your home; however, selecting the right model requires a little more consideration than other humidifier models! 

GeneralAire® steam humidifiers utilize electrode steam technology, whereby electric current is passed between electrodes inside a water-filled canister to heat the water within and create steam.  This technology relies on water conductivity (provided by the presence of natural minerals in the water) in order to efficiently pass electric current between electrodes. Knowing your water's conductivity helps to determine which model steam humidifier you should install. If your water does not have ample conductivity, steam humidification may not be the right choice for your home.

Along with conductivity, you'll need to know the gallons per day required to supply your home with the humidity you need (and desire).

Calculating Gallons Per Day:

(Save time, by using our humidity calculator on www.generalfilters.com / support center).

  1. Determine The Total Cubic Feet Of The Home:
    1. Sq. Ft. Of Your Home (Basement Included) X Ceiling Height
  2. Calculate The Load (Lbs./Hr.):
    1. Total Cubic Feet X Desired Condition Factor (From Table Below)
    2. X 1.05 For Each Fireplace

  1. Calculate Gallons Per Day Your Home Will Need To Achieve Desired Humidity Levels: 
    1. Gallons Per Day X Load (Lbs. / Hr.) X 2.88.

Testing Water Conductivity:

  1. Using our AP-2 Digital Water Tester, test the water for electrical conductivity (measured in microSiemens per centimeter (µs/cm).  
  • 100 to 500 µs/cm – Requires a Low Conductivity (LC) model.
  • 300 to 1,25µs/cm – Requires a Regular steam model.

Selecting Your Unit:

  1. Now that you know gallons per day and conductivity levels, what is the last step?  Select the model! 
  • Room Steam (RS) or Duct Steam (DS) models that accommodate your installation needs (DS Models require an installation kit).
  • Gallons Per Day (GPD) – From 16 to 58
  • Regular or LC (Low Conductivity) models, based on your water conductivity results.
  • Learn more here.

More Tips:

  • Do NOT use softened water, but rather ensure the water supply to your steam humidifier is untreated.
  • Do NOT use water containing disinfectants, corrosion inhibitors, or any chemically or bacteriologically-contaminated water.
  • Do NOT use a hot water supply.
  • When in doubt, select the humidifier that produces MORE gallons per day than what is required.  Why?  Home owners may choose to remodel, install wood flooring (where there was none before) or add space / rooms on to their home. All these situations increase the demand for humidity.  If your humidifier cannot keep up with this increased demand, you may have an unhappy home owner. 

Overall the steam humidifier must be supplied with the following water characteristics:

  • Pressure between 20psi and 110psi; or 0.1 and 0.8 MPa (1 and 8 bar)
  • Temperature between 33° F and 104° F; or 1° C and 40° C
  • Flow rate minimum of 0.45 L/min or 0.21 gpm
  • Hardness no greater than 40° fH (equal to 400 ppm3 of CaCO),
  • Conductivity from 125 to 1250 µS/cm
  • Absence of organic compounds 

Table of Contents

Full History

1937
general-filters-timeline-1937

Founded in Detroit

General is founded by Art and Grace Redner in Detroit, Michigan, marking the beginning of a family legacy.
1939
general-filters-timeline-1939

Supporting the War Effort

General begins manufacturing filters for bomber ground support equipment during World War II.
1943

Expanding Operations

General moves to a new Detroit location at Schoolcraft and Grand River.
1946
general-filters-timeline-1946

New Detroit Home

General relocates to 12890 Westwood Avenue in Detroit, strengthening operations in Michigan.
1948

Growth into Canada

Canadian General Filters Ltd. is founded, extending reach to North America.
1953

Relocation to Novi, Michigan

General Filters moved to its current location in Novi, Michigan, marking a major milestone in its evolution as a manufacturing company.
1958
general-filters-timeline-1958

Model 250 Humidifier Introduced

The Model 250 set a new standard for whole-home comfort, helping families maintain healthy humidity and improve indoor air quality.
1962
general-filters-timeline-1962

New Oil Filters Introduced

1969
general-filters-timeline-1969

Model 1040 Humidifier Debuts

General Filters introduced the Model 1040 humidifier, a breakthrough product that helped define whole-house humidification.
1983
general-filters-timeline-1983

AC 1 Air Cleaner Introduced

General Filters introduced the Model 1040 humidifier, a breakthrough product that helped define whole-house humidification.
1997
general-filters-timeline-1997

Steam Humidifiers Introduced

The GeneralAire Model 5500 provides clean, sterile moisture with a furnace-independent design, disposable cylinder, digital diagnostics, and included humidistat.
2006
general-filters-timeline-2006

Gar-Ber® Acquisition

Gar-Ber Spin-On residential fuel oil filters were acquired by General Filters and continue to be manufactured to the same trusted specifications.
2006
general-filters-timeline-2006-elite

Elite Humidifiers Introduced

2009
general-filters-timeline-2009

Advanced TERSus Technology Introduced

2014
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Dehumidification Expansion

The acquisition of Air & Energy Products expanded the company’s whole-house dehumidifier offerings.
2018
general-filters-timeline-2018

Advanced Air Solutions

Wi-Fi-enabled dehumidifiers were introduced under the GeneralAire® brand, and Second Wind™ Air Purifiers were acquired to expand UV air purification solutions.
2018
general-filters-timeline-2018-touch-screen

Touch Screen & Wi-Fi Control

GeneralAire DH75 and DH100 whole-house dehumidifiers (75-100 pints/day) feature LCD touch screens and Wi-Fi capability via the GeneralAire App for remote monitoring.
2019
general-filters-timeline-2019

Touch Screen & Wi-Fi Control

GeneralAire DH75 and DH100 whole-house dehumidifiers (75-100 pints/day) feature LCD touch screens and Wi-Fi capability via the GeneralAire App for remote monitoring.
2020
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Model 5500 Steam Humidifier Introduced

2020
general-filters-timeline-2020-brand-refresh

Brand Logo Refresh

New GeneralAire®, General Filters, and Canadian General Filters Brand Logos Introduced
2020
general-filters-timeline-2020-vapor-pad

Model 3200 Evaporative Humidifier Introduced

2020
general-filters-timeline-2020-model-4200

Model 4200 Evaporative Humidifier Introduced

2020
general-filters-timeline-2021

Industry Standard Vapor Pad Lineup Introduced

2021
general-filters-timeline-2021-bio-gasket

BioGaskets Included in All Gar-Ber Oil Products

2021
general-filters-timeline-2021-merv

Introduced MERV 13 Filters

2023
general-filters-timeline-2023

Model 4400A Fan-Assist Evaporative Humidifier Introduced