Note: This equipment type requires 2 consecutive output channels 1&2, 3&4, etc. The first channel (odd numbered) must be wired to OPEN the vent, and the other (even numbered) to CLOSE it.

Here is a video to give you a more in depth understanding

iGrow1400 Vent Programming

The vent opening is defined in percentage terms where 0% is vent closed and 99% is where the vent is fully open. NORM is the normal stage when neither heating nor cooling is usually required. C1 is the lowest stage of cooling, and C6 is the highest (or maximum) cooling stage. Enter your desired vent opening percentage for each of the stages.

Wind Overrides

Wind overrides limits are important for safe and effective vent operation. Of course, a weather station (or Link4 anemometer) must already be installed to use this feature. First you have to set Dir, which is the direction that the vent faces when open. You have eight choices. N, NE, E, SE, S, SW, W, NW.

Next, you will need to set a Min and Max vent opening for the case with the wind blowing into the vent (Windward) and similarly for the case where the wind is blowing across or over the vent (Leeward). The program calculates an average wind speed. This is a running average over approximately 5 seconds. Once the average wind speed exceeds the Min value the vent begins to close. As the wind speed increases and approaches the Max value, the vent will go to the full close position.

 

 The Wind Ovr Hold parameter is the length of time in minutes that the vent will remain in its override position once the wind speed is below the minimum threshold. This is to keep short wind gusts from causing the vents to constantly open & close.

The Rain MaxOpen percent is the maximum vent position once rain is detected.

EXAMPLE:

The wind override has higher priority than rain. Suppose the vent is open 50% and it begins to rain. From the entry in the above screen, the vent will close down to 5%. Now assume that the wind picks up and exceeds 30 mph with the wind blowing into the vent. The vent will then go to a full close.

The Open Time is the time in minutes and seconds that it takes for the vent to go from its full closed to full open position or vice versa

The fourth screen below is for insuring that the vent does not open beyond a preset percentage if the outside temperature is below a user defined threshold.

The Vent MaxOpen is the max that the vent will go open if the Otemp is less than the number of degrees that you enter. In any case, wind and rain overrides will have precedence.

In the fifth and final screen, the vent can be programmed to go to a minimum opening if the outdoor temperature exceeds a plus or minus value relative to the cool temperature setpoint. This override is anticipatory and is particularly useful for the open roof vent configuration or the side roll up vents. It is also useful, if one wants to minimize the vent movements, by just leaving the vent in a fixed position as long as the outside temperature exceeds some offset from the cool setpoint temperature.

The Vent Min Open is the minimum position for the vent when the Otemp exceeds the CoolSetP plus an offset temperature. This feature helps improve efficiency by using outside air to cool the greenhouse rather than fans or Pads. As with the previous screen, wind and rain overrides will have precedence.

EXAMPLE: 

Suppose you have an open roof vent and you want to it go to its maximum position when the outside temperature is 3 degrees below the cool setpoint which during the day is 70 degrees. You will then enter 99 for the Min Open value and –3 for the offset value. Once the outside temperature exceeds 67 degrees, the roof vent will, in this example, go to 99% or full open.

And Finally, The Linkconn 1000 Software view of Vent Programming which provides descriptions of all overrides as previously discussed as well as the options to utilize Relative Humidity and Time Overrides.