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Ultra-Aire 98H Installation Instructions
www.Ultra-Aire.com | (800) 533-7533
The recommended installation creates a separate return for the Ultra-Aire 98H in a central area of the
structure. Duct the supply of the unit to the air supply of the existing HVAC system. Connect an insulated
duct from outside to the 6" collar of the Ultra-Aire 98H to provide fresh make-up air.
DUCTING TO HVAC SYSTEMS
CAUTION!
DO NOT CONNECT WITH A STATIC PRESSURE GREATER THAN OR EQUAL TO +0.5 WG.
CONTACT TECHNICAL SUPPORT AT (800) 533-7533 FOR ADDITIONAL DETAILS.
Ducting Considerations:
• All flexible ducting connected to the Ultra-Aire 98H should be UL listed.
• A short piece of flexible ducting on all Ultra-Aire 98H duct connections is recommended to reduce noise
and vibration transmitted to rigid ductwork in the structure.
• Use a minimum 10" diameter round or equivalent rectangular duct for total duct lengths of up to 25'. Use
a minimum 12" diameter round or equivalent rectangular duct for longer lengths.
• Grills or diffusers on the duct ends must not excessively restrict airflow.
• A length of 10" or more of insulated flex duct or any other vibration isolating material on the outlet of the
Ultra-Aire 98H will reduce air noise from the blower.
• Effective dehumidification may require that ducting be branched to isolated, stagnant air flow areas.
When ducting to two or three areas, use 8" or larger diameter branch ducting. When ducting to four or
more areas, use 6" or larger diameter branch ducting. Provisions must be made to provide airflow from
supply locations to the central return location. Proper air distribution is important to ensure even humidity
control and heat distribution throughout the structure.
• DO NOT locate the return in a bathroom or a kitchen.
