Humidifier Sizing Chart (8’ Ceilings)
Structure Tightness 1000 ft21500 ft22000 ft22500 ft23000 ft24000 ft25000 ft2
Humidity needed (GPD per AHRI)*** Guideline F
Tight 4.3 6.4 8.5 10.6 12.7 17 21.2
Average 8.6 12.8 17 21.3 25.4 34 42.6
Loose 12.7 19.1 25.5 31.8 38.1 51 63.6
* = Automatic Digital Control (shown)
** = Manual Control For those rare occurrences where an automatic control is not practical, Aprilaire digital control can be installed in manual mode while still delivering the
accuracy and information you need for optimum performance.
Warranty – All Aprilaire models are warranted for five (5) years from date of installation for parts.
Heat Pumps – Plumbing the humidifier to hot water is recommended on all heat pump installations or if it is installed to operate independently of a call for heat.
(See ^NOTE for Model 400)
Bypass humidifiers can be installed on the supply or return plenum. Complete with install kit.
• Water feed rate for the Model 700, 350 and 360 is 6 gph; the Models 500 and 600 is 3 gph; Model 400 is .7 gph: Model 800 is .6 gph when connected to 120V, 1.1 gph when
connected to 208V and 1.18 gph when connected to 240V. (gph = gallons per hour)
*** = AHRI Air Conditioning, Heating, and Refrigeration Institute GPD = Gallons Per Day Guideline F
• A family of 4 will add 2 gallons of humidity per day through everyday activities like breathing, cooking, bathing and washing.
• Evaporative capacities assume blower is active 100% of the time, plenum temperature is at 120˚F and water is cold.
Aprilaire Selection Guide Specifications
MODEL
Model 400K*/400MK** Model 500K*/500MK** Model 600K*/600MK** Model 700*/700M** Model 800
Bypass Unit –
Uses 100% of
water and
evaporative
technology that
eliminates the
need for a drain.
Bypass Unit –
Designed for
smaller homes.
Bypass Unit –
Uses the furnace
blower to move
air through a
Water Panel®.
Powered Unit –
Built-in fan that
pulls heated air
directly from
the furnace.
Steam Humidifier –
For applications when
evaporative units
are less practical
(attics, crawl spaces,
closets, milder winter
climates, non-forced
air heating source).
CAPACITY
gpd = gallons per day 17 gpd 12 gpd 17 gpd 18 gpd 11.5 gpd 20.5 gpd 23.3 gpd
120 volts 210 volts 240 volts
www.AprilairePartners.com
Easiest to Install
• Fully assembled
• Installation kit included with bypass units
• Installs in six easy steps
• Simple, annual maintenance
Bypass installation kit
Installation kit
included with
bypass units
Form No. 261
