Aprilaire Ventilation System
Model 8126X | Specification Sheet
Features
- Includes 8120X ventilation controller, damper, 24VAC transformer, outdoor temperature sensor and duct board bracket for 8120X.
- Configurable for Code or Comfort modes (factory default is Comfort).
- Monitors outdoor temperature to regulate ventilation based on adjustable high and low temperature lockouts.
- Monitors indoor humidity to regulate ventilation based on adjustable high and low humidity lockouts.
- Features patented control programming that maintains ASHRAE 62.2-2010 compliance, even during high and low temperature limit lockouts. (Patent No. 9,874,366)
- Damper is designed to remain in the ductwork even if the actuator fails.
- Offers installation flexibility, allowing for override of humidity and temperature control.
- Provides easy access to rater information, such as the amount of CFM brought into the home.
Benefits
- Designed to meet ventilation requirements and conform to the latest building and energy codes.
- Simple installation and setup process, saving time and resources.
- Enhances customer comfort and provides energy savings compared to other economical ventilation options.
- Offers flexible setup options to suit various application needs.
Product Specifications
| Specification | Value |
|---|---|
| Overall controller dimensions | 411⁄16" W x 33⁄5" H x 15⁄16" D |
| Duct opening dimensions (for humidity sensor) | 5⁄8" dia. in sheet metal, 53⁄4" x 51⁄2" for duct board (duct board bracket included) |
| Input power for the control (from the HVAC system transformer) | 24VAC, 2VA |
| Damper (vent) and GH outputs | 10VA @ 30VAC max |
| HVAC equipment terminals | R, C, W, Y, O, GS, GH |
| Equipment compatibility | Furnace and AC or Heat Pump |
| Outdoor temperature sensor inputs | Thermistor (provided) |
| Damper transformer (provided) | 24VAC, 10VA |
| Compliance | ASHRAE 62.2-2010 |
| Installation temp limits | 20°F–140°F |
| Damper size | 6" dia. |
| Overall damper dimensions (with actuator) | 103⁄4" H x 102⁄5" dia. |
| Max static pressure | 1" w.c. |
| Max system velocity | 1000 ft/min |
| Total power consumption | 10VA (6 watts) |
Diagram Descriptions
Controller and Damper Dimensions: Visual representations show the Aprilaire Ventilation Controller (Model 8126X) with dimensions of 411⁄16" W x 33⁄5" H x 15⁄16" D (Reference 90-2286). The damper, with its actuator, is shown to be 103⁄4" high and 102⁄5" in diameter (Reference 90-2159).
Operation
Controller Interface
The controller interface displays the ventilation time setting (minutes/hour), the current mode of operation (Code or Comfort), and indicates if the HVAC fan is active during ventilation. The display is dim by default and brightens upon the first button press. A green light indicates active ventilation.
Controls:
- Rater/Inspector Verification Button: Press and hold for 5 seconds to enter Test Mode or the Set Up Menu.
- Override Button: Used to manually adjust the calculated ventilation time setting (6-60 minutes/hour). Press and hold to turn ventilation off. To revert to the calculated setting, cycle through the Set Up Menu.
Sequence of Operation – “CODE” Setting
In "Code" mode, the vent damper opens for a predetermined number of minutes per hour, triggered by a heating, cooling, or fan call. Ventilation is restricted if the outdoor temperature exceeds the high lockout limit during a cool or fan call, but proceeds with a heat call if below the low lockout limit.
If the HVAC system doesn't run long enough to meet the set ventilation time within an hour, the control will activate the vent damper and the HVAC blower independently, provided the outdoor air temperature is within the specified high and low limits.
If the outdoor temperature is outside the set limits at the end of a one-hour cycle, no further ventilation occurs for 60 minutes, and the cycle period automatically extends to four hours. The system then attempts to meet the ventilation requirements within this extended period.
If the temperature remains out of range after the four-hour cycle, the system progresses through eight-hour, 12-hour, and finally 24-hour cycle periods. During these longer cycles, the total ventilation time is increased to ensure effectiveness as per ASHRAE Standard 62.2-2010.
Once the cycle period reaches 24 hours, ventilation will activate to meet requirements regardless of the outdoor temperature being outside the set limits. (Patent No. 9,874,366)
Sequence of Operation – “COMFORT” Setting
In "Comfort" mode, the vent damper opens for a set duration per hour if the outdoor air temperature is within the high and low ventilation limits AND the indoor relative humidity (RH) is within the specified high and low RH limits.
If the HVAC equipment does not run sufficiently to meet the required ventilation time within the hour, the control will open the vent damper and activate the HVAC fan without a call, provided both outdoor air temperature and indoor RH are within their set limits. If either the outdoor temperature or indoor RH is outside the set limits, no ventilation will occur.
Installation Diagrams
Sheet Metal Installation: This diagram illustrates the installation of the damper in a sheet metal duct. It shows a wall plate, pilot holes for screws, a 5/8" diameter hole for the damper, and a minimum 6" clearance for the fresh air duct. The damper is positioned within the duct. Reference number 90-2269.
Duct Board Installation: This diagram shows the damper installation in duct board. It includes a return duct, fresh air duct, a duct board bracket, and a wall plate. The diagram specifies a 6" minimum for the return duct and indicates the placement of the damper. It also shows a 53⁄4" x 51⁄4" opening for the duct board bracket and the use of #8 pan head screws. The controller is mounted to the side or top of the plenum, with a note to use cut-out insulation to insulate the duct board bracket around the controller. Reference number 90-2264.
