Therma-Stor Products Group Ultra-Aire 100V 3.4C Ducting for Fresh Air, For Hvac Installer Only

FOR HVAC INSTALLER ONLY

a separate supply duct from the Ultra-Aire to each isolated area is recommended. DO NOT draw air directly from the kitchen, laundry, or basement. All flexible ducting connected to the Ultra-Aire should be UL listed.

The inlet of the Ultra-Aire is the 8" diameter hole on top of the unit. An 8" round collar is supplied with the unit to attach to round duct. The duct may be permanently attached to the collar. A 6" round collar is provided with the unit to attach to the 6" hole in the top. The 6" collar should be capped if fresh make-up air is not desired. If fresh make-up air is desired see section 3.4C.

The outlet of the Ultra-Aire is located on the side of the unit. A second 8" round collar is supplied with the unit and can be attached using the screws provided and the pre-punched holes in the cabinet side.

A length of 10 feet or more of acoustical flex ducting on the outlet of the Ultra-Aire will reduce air noise from the blower. A length of flexible ducting on all Ultra-Aire duct connections is recommended to reduce noise and vibration transmitted to rigid ductwork in the structure.

Ducting the Ultra-Aire as mentioned in sections 3.4A-3.4G requires consideration of the following points:

Duct Sizing: For total duct lengths up to 25', use a

minimum 8" diameter round or equivalent rectangular. For longer lengths, use a minimum 10" diameter or equivalent. Grills or diffusers on the duct ends must not excessively restrict air flow.

Isolated Areas: Effective dehumidification may require that ducting be branched to isolated, stagnant areas. Use 6" or larger diameter branch ducting to each of two or three areas; use 4" or larger to each of four or more areas.

3.4C Ducting for Fresh Air

Fresh air can be brought into the structure by connecting a duct from outside to the 6" Ultra-Aire inlet and by turning on the fan switch or activating the humidity control on units with the humidity control panel. Activate the ventilation timer on units with the ventilating & humidity control panel to bring in fresh air. Advantages of this form of ventilation include:

1.Outside air is filtered before entering the building.

2.Outside air will be dehumidified before entering if the Ultra- Aire is running.

3.Drawing air from outside and blowing inside aids in slightly pressurizing the structure. This helps prevent unfiltered and undehumidified air from entering elsewhere. It also reduces the potential for carcinogenic radon gas to enter and provides makeup air for open combustion and exhaust devices like the clothes drier, fireplace, and water heater.

4.The need for an alternate ventilation device may be eliminated.

An insulated 6" diameter duct is generally sufficient to provide up

to 125 CFM of outside air. Large quantities of outside air will impact Ultra-Aire performance positively or negatively, depending upon the difference between inside and outside air conditions. Consult the factory by calling 1-800-533-7533 for recommendations regarding the use of higher flows with your specific application.

The outside air duct should be connected to the 6" round collar on top of the unit. The 6" round collar includes a manual damper. Adjust the manual damper to provide the desired amount of fresh air for ventilation. The amount of fresh air should be based on the size and occupancy of the residence. If you are unsure of your ventilation air requirements, consult the factory by calling 1-800-533-7533 for assistance.

3.4D Installation in a Basement or Crawlspace with an Existing Forced Air HVAC System.

If the structure in which the Ultra-Aire is to be installed has an existing forced air HVAC system, utilize the HVAC system to make the Ultra-Aire installation easier.

If the existing system has multiple returns, select one to disconnect from the existing forced air system and use it for the dedicated Ultra-Aire return. Always select a return from a central location

in the structure in an area that is always open to the rest of the structure. Do not use a return from a room that may have its door closed much of the time.

Basement Installation: Locate a separate return for the Ultra-Aire in a central area of the structure. Duct the supply of the Ultra-Aire to a 8" x 8" x 8" tee/damper that is 30% open to the basement.

Duct the other side of the tee to the air return of the existing HVAC system. If the existing HVAC system has a central return, duct the other side of the tee to the air supply of the existing HVAC system.

5 Ultra-Aire 100V Installer’s & Owner’s Manual