Video Walls
Video walls are one of the newer applications that require ventilation and often times, a lot of it! The challenge at this point and for providing information like this is we haven't seen a lot of norms with the installation of video walls so we'll just discuss situations that we have encountered thus far and really the principles still remain the same as cooling other devices, start by considering natural airflow, work with the rising heat, pre-plan as much as possible, focus on getting air moving evenly... Additional considerations are also if require silent cooling and where can vent to...
Ducting Accessories. The general idea is multiple vents will be used and the ducting will come to one point and merge into a single duct to be extracted by a duct fan. In other words, may have 4 3" exhaust vents that are then connected to a single 8" fan. There are a few options for that connection depending on the size fan and number of vents.
First, do not just leave the exhaust port of the fan without any ducting. Even if the fan is located where are exhausting to, there should still be at least 5' duct and with a bend or two to help create proper pressure in the system. Beyond that, we already recommend venting to an HVAC return, never to outside the air conditioned space as the air should be recycled through the system since it has already been 'process' (humidity removed...) and with these systems we are talking a tremendous amount of airflow.
Direct Venting via Remote Ducting. One of the best ways to vent a video wall is with ducting and with several exhaust ports located toward the upper part of the wall. Depending on the size of the wall, this could be perhaps 2, perhaps 3 or 4, or really any number of exhaust ports and the ports could be in the wall behind the wall or in an upper soffit or bulkhead depending on the design. The idea is we're exhausting air more evenly which also means we're drawing cooler air throughout the wall more evenly as well.
One thing to note is when ducting and connecting multiple ducts to a single fan, the ducts need to be balanced and what causes an imbalance is unequal duct lengths, one duct with bends while another is straight, different types of ducting... Here's an example in looking at the graphic, the S curved ducts can be a little shorter than the ducts with the swoop curves because the sharper bends are restricting the airflow the same as the added length of the ducting. The balance does not need to be perfect but should be close and it can also be regulated almost countless ways. Dampers could be used or simply blocking the intake vent and a good strong tape would work. To do this should use an anemometer (airspeed gauge). If use the 4x8 duct box then can use a grill where the airflow can be adjusted as well.
Recommended Products For Remote VentingDuct Fans. We of course recommend using the EC (electronically controlled) fans which provide advanced control functions when used with the EC controller. The on/off and variable speed control are important features for this application. The 6" version is the 'base' for this application and would be appropriate for a 4 panel display but for larger displays would want to use the 8" or 10" or for a big wall and to get pretty extreme, we also have a 12" version. May also consider multiple fans for redundancy as well.
Inline Duct Fan - 6". This is really the absolute minimum amount of airflow so may be useful if there is natural airflow in and around the displays and the venting is secondary.
Inline Duct Fan - 8". This is usually the standard for basic video walls as it's enough airflow to support multiple vents.
Inline Duct Fan - 10". This is aggressive but still a logical step up if using 3+ vents.Inline Duct Fan - 12". This is where get pretty extreme but with the variable speed fan it's hard to say it's overkill.
Ducting Accessories. The general idea is multiple vents will be used and the ducting will come to one point and merge into a single duct to be extracted by a duct fan. In other words, may have 4 3" exhaust vents that are then connected to a single 8" fan. There are a few options for that connection depending on the size fan and number of vents.
Vent Elbow. This is good for in-wall exhaust ports behind a video wall. It mates with 4" ducting but the port is obround so still fits into a 2x4 wall and the opening mates with this 4" grill. When running 3 or more ducts may want to use 3" ducting and those the other Duct Boxes as the air can be regulated easier with the smaller ducting. 4" ducting would be appropriate when using just 1 or 2 vents and the 8" fan or a 6" fan if the duct lengths are within 10'.
Inline Vents. This is ideal for soffit/bulkhead venting as 3" ducting connects directly to the vent but there must be space for the vent and ducting so this cannot realistically be used in a wall cavity.Duct Box 4x4 & Duct Box 4x8. These can also be used in a 2x4 wall and connect with 3" ducting. These would also be recommended over the Vent Elbow if want to use vents to inject cooler air as the 3" ducting would be better for that application.
Recommended Products For Direct/Local Venting
This is for venting video walls with cooling products mounted behind or around the perimeter of the wall. There are many ways that walls are installed, either recessed, with a frame... so this is all just ideas for the installer which of course then requires tailoring the products to the application.
This is for venting video walls with cooling products mounted behind or around the perimeter of the wall. There are many ways that walls are installed, either recessed, with a frame... so this is all just ideas for the installer which of course then requires tailoring the products to the application.
HiFlo Lite Pro. This product is appropriate if planning to install multiple vents and a minimum of 4 of the vents. It can be recessed into a side frame or installed on the back of the frame with a 3 to 3 1/2" hole drilled through the frame.
HiFlo Pro. This is more significant cooling but at least 2 units would be required for smaller display walls. It can be used and installed much like the HiFlo Lite.
SlimSix. The main advantage of this unit is the more narrow profile and semi-aggressive amount of airflow. This would be appropriate if the frame around the wall is narrow.
Universal Cooler. This would be used more for mounting on the wall behind the displays and blowing air from behind the displays and the angle allows the airflow to the directed out and away from the displays.
Temperature Controllers
Advanced LT Pro. This on/off and variable speed controller and is typically a local controller but the sensor and fan leads can be extended if wish to locate it with the equipment.
Advanced LT 3-Fan. Same as above except it controls 3 banks of fans independently. One potentially application is if want to control top, side, and intake fans independently. The unit could also be used to control 2 banks of fans and use the 3rd to trigger a 12V input for alarm on a control system.
Advanced System Controller. This is a fully programmable controller with various features including trigger for on/off (still recommend using temperature based control), alarm features including contact closures...
Advanced System Controller - Dual. Same as above but dual and rack mountable.
Advanced Ventilation Controller. This is actually a high voltage controller but with multiple relays which means would only have on/off control (not variable speed) but the advantage is it is more like an on-wall thermostat, is programmable and provides a lot of different control options.
Exhausting the Hot Air
First, do not just leave the exhaust port of the fan without any ducting. Even if the fan is located where are exhausting to, there should still be at least 5' duct and with a bend or two to help create proper pressure in the system. Beyond that, we already recommend venting to an HVAC return, never to outside the air conditioned space as the air should be recycled through the system since it has already been 'process' (humidity removed...) and with these systems we are talking a tremendous amount of airflow.