Schools and offices buy interactive panels from a catalogue and then discover the back row cannot read them. This page shows you how to size a screen to your room, why the 4/6 rule matters, and the six mistakes that leave a panel used as a whiteboard.
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Uses the 4-6-8 rule: furthest viewer no more than 4, 6 or 8 image heights away. For a 16:9 screen, image height is 0.49 × the diagonal.
The headline product is rarely more than half the installed cost. These are the parts that get left out of budgets.
Sized to the room, not the budget. Includes touch and built-in Android in most models.
Fixed mount for dedicated rooms; mobile stand where the panel moves between rooms.
Behind the panel. Retrofitting a socket after mounting means visible trunking.
Slots into the panel for full Windows. Needed for software the built-in Android cannot run.
Lets any laptop or phone cast without cables. The feature staff use most.
For showing physical objects, books and worked examples.
Turns the panel into a video conferencing room.
Two hours at handover. This is what determines whether the panel is used or ignored.
The honest trade-offs.
| Consideration | Interactive Panel | Projector + Board | Standard TV | LED Video Wall |
|---|---|---|---|---|
| Readable in daylight | Yes | Poor | Yes | Yes |
| Touch interaction | Yes | With sensor bar | No | No |
| Consumables | None | Lamp / filter | None | None |
| Max practical size | 110″ | Very large | 98″ | Unlimited |
| Maintenance | Minimal | Regular | Minimal | Moderate |
| Best for | Classrooms, boardrooms | Large halls, auditoriums | Signage, passive display | Lobbies, large venues |
| Relative cost | Moderate | Lowest upfront | Lowest | Highest |
Measure to the back row first. Everything follows from this number. A catalogue cannot tell you what size your room needs.
Check the room width fits the screen. A screen should occupy roughly 60% of the wall width at most. An 86″ panel needs about 6.5 feet of clear wall.
Power behind the mount position. Fitted before the panel goes up. Afterwards it means surface trunking down the wall.
Wall structure. Panels above 75″ are heavy. Brick and concrete are fine; partition board needs backing plates.
Glare and window position. A panel facing windows will glare. If the layout cannot change, blinds are part of the installation, not an extra.
Network for updates and casting. Wireless presentation and firmware updates both need Wi-Fi at the panel position.
No consumables is the main financial advantage over projectors. No lamps, no filters, no bulb replacement cycle.
Panel lifespan is typically 30,000–50,000 hours of use, which at classroom hours is many years. The touch layer usually outlasts the institution's interest in the technology.
Power draw is modest — comparable to a large television, and considerably less than a projector plus its cooling.
Software licences, where the panel runs proprietary teaching software, may be annual. Confirm before choosing a platform; the built-in Android tools are usually sufficient.
The cost nobody accounts for: an unused panel. Institutions across Bangladesh have interactive displays being used as plain whiteboards because nobody was trained. Two hours of training at handover is the difference between an asset and an ornament — we include it.
Every one has cost a real project real money.
A 65-inch panel in a room that needs 86 inches means the back rows disengage. The screen works; the teaching does not.
Do this: Measure to the back row, apply the 4/6 rule, then find a product in that size.
A large panel too close causes real eye strain and neck movement. There is a minimum distance as well as a maximum.
Do this: Keep the front row at least 1.5 times the screen height away.
Daylight glare defeats even a bright panel, and the room cannot be rearranged after the wall bracket is in.
Do this: Assess glare at survey. If the layout is fixed, budget blinds as part of the install.
Discovered on installation day. The result is a cable running down the wall in surface trunking.
Do this: Electrical point at mount height, fitted before the panel goes up.
Some school and CAD software needs Windows. The built-in system will not run it.
Do this: Confirm your software requirements first. Add an OPS PC module if needed.
The single biggest cause of unused panels in Bangladesh. Staff default to using it as a whiteboard.
Do this: Two hours at handover, and a named person who owns it. We include the training.
Specifications, models and pricing sit on the product pages.
Rules we apply on every installation. Share this with your installer.
The furthest viewer decides the screen. The 4-6-8 rule: no further than 4, 6 or 8 image heights for text, lessons or video.
About 1.2–1.3 m to screen centre in a classroom. Too high causes neck strain.
Direct sun on an anti-glare panel still washes it out. Fit blinds before the panel.
Decide Windows (OPS module) or casting only before cables are run.
Lifts, stairwells and door widths decide whether a 98″ or 110″ panel can reach the room.
Voltage swings when power returns after load-shedding are hard on panel power boards.
Measure from the screen wall to the back row, then apply the six-times-screen-height rule for mixed teaching content. A room with a back row at 24 feet needs roughly an 86-inch panel. Most Bangladeshi classrooms buy 65-inch for rooms that need 86-inch, and the back rows disengage.
Room size decides it. In a normal classroom a panel wins on daylight readability and has no lamp cost. In a large hall above roughly 110 inches of required image, a projector scales far more cheaply. Note that projector lamp replacement often exceeds the price gap within a few years of classroom use.
Yes, and it gets overlooked. The front row should sit at least 1.5 times the screen height away — closer causes genuine eye strain and constant neck movement. A large panel in a small room is as much a mistake as a small panel in a large one.
Only if your software needs Windows. Most panels include built-in Android with browser, whiteboard and screen-sharing, which covers ordinary teaching use. School management software, CAD and some assessment platforms need Windows — confirm your requirements before ordering.
None. No lamps, no filters, no bulbs. This is the main financial advantage over projectors and the reason the total cost of ownership often favours a panel despite the higher purchase price.
Because nobody was trained. Institutions across Bangladesh have panels being used as plain whiteboards. Two hours of training at handover, plus a named person who owns the equipment, is the difference between an asset and an ornament — we include the training with every installation.
Measure to the back row. A 20 ft room showing lessons needs about an 82″ image, so an 86″ panel. Enter your room in the calculator.
Most rooms are under-sized. A 16:9 screen's height is only 0.49 × its diagonal, and text must be readable from the last seat.
Free site survey across Dhaka and Chattogram. Our engineers confirm the design before anything is quoted.