Pick the screen for the daytime room and solve the night window separately. A 75 inch touch board sized for a 13 ft table can also run the window loop if its spec sheet names built-in signage playback with loop, scheduled and interval modes; otherwise keep the board for people and give the glass a small offline sign that autostarts its playlist from a card, with no subscription.
A 75 inch touch board and a night-time window loop pull one purchase in two directions. The board wants size, touch and a room. The loop wants scheduled power-on, autoplay from storage and brightness behind glass. Buy the screen for the room, because that job sets the size, and solve the night job one of three ways: a board whose spec sheet names built-in signage playback, a small media player on a plug-in timer, or a dedicated offline sign for the glass. This page gives the sizing numbers for both jobs, the timer behaviour to test before mounting, and the exact spec-sheet words to demand.
What the night job actually needs
Three behaviours decide whether one screen can do both jobs:
- Scheduled power-on. The screen has to wake itself at your evening hour, from its own menu timer or from mains restored by a plug-in timer.
- Autoplay from local storage. Whatever plays the loop must start its playlist on its own when power arrives and loop it with nobody logging in.
- Brightness behind the glass. Street lights and shop reflections sit between the passer-by and the panel.
Touch is a daytime requirement only; the night viewer never touches the glass. That matters because interactive boards are presentation computers first, and some ship with no looping signage player at all. Other boards, mostly Android smart boards, list built-in digital signage with USB media playback in loop, scheduled and interval modes. The spec sheet settles it in one line: those words present, the board can fly solo at night; the words absent, plan for a player route below.
The three routes, side by side
| Route | Night job | Subscription | Touch kept | Test before you buy |
|---|---|---|---|---|
| Board with built-in signage modes | Board's own playback from USB or internal storage, on its own schedule | Confirm with the vendor; offline modes need none | Yes, same panel | Spec sheet names loop, scheduled and interval playback; on/off timer works in the menu |
| Touch board plus media player | Small player feeds the board's HDMI input; a plug-in timer wakes both | Player-dependent; offline players have none | Yes | Player autoplays at power-up; board powers on when mains returns |
| Touch board plus dedicated window sign | Small offline sign behind the glass runs its own playlist on a card | None | Yes, board untouched | Sign autostarts its playlist from the card at power-on |
We answered the same one-screen-or-two question for a clinic waiting room, and the ending is usually the same here: the second job is cheap enough to give it its own screen, and each screen stays simple.
Sizing example: a 13 ft meeting table and a 12 ft window
Inputs. Farthest viewer at the table: 13 ft, a typical 12 to 14 ft meeting room; use your own room's number. Passer-by to screen: 12 ft at the window, about 11 ft of sidewalk plus 1 ft behind the glass. Text rule: the FHWA planning figure of 30 ft of viewing distance per inch of capital letter height, with 20 ft per inch the safer choice for fast reading. Screen rule: AVIXA's DISCAS standard sizes by image height, about 7 image heights from the farthest viewer for slides and video, about 3 image heights for fine detail.
Rules in words. Text: the capital letter height must reach the distance divided by 30, or by 20 for fast reading. Screens: the image height must reach the farthest viewer's distance divided by 7 for slides, or 3 for detail.
Arithmetic. Window: 12 ft ÷ 30 = 0.4 in capitals minimum; 12 ft ÷ 20 = 0.6 in for fast reading. A 15.6 inch 16:9 panel stands 15.6 × 9 ÷ 18.36 = 7.6 in tall, so a 0.6 in headline fills about 8% of its height. Window text asks almost nothing of the screen. Room: minimum image height for slides is 13 ft ÷ 7 = 1.86 ft = 22.3 in. Convert to diagonal by multiplying by 18.36 ÷ 9 = 2.04: 22.3 × 2.04 = 45.5 in. So about 45 inches of diagonal is the slide floor for a 13 ft room. The 75 inch check: image height is 75 × 9 ÷ 18.36 = 36.8 in = 3.07 ft. Slide reach: 3.07 × 7 = 21.5 ft, which clears the 13 ft room with 8.5 ft of margin. Detail reach: 3.07 × 3 = 9.2 ft.
Result and decision. Any 16:9 board from about 45 inches up shows slides to everyone in a 13 ft room; 75 inches buys margin plus fine-detail viewing to 9.2 ft, so detailed drawing review happens within about 9 ft or by zooming in. The window loop needs a 0.6 in headline, which every screen on this page delivers, so the night job never sets the diagonal. The full method, including portrait layouts, is in our screen size guide.
Waking the screen on schedule
Two clocks can start the evening: the display's own on/off timer, or a plug-in timer on the mains.
Start with the display. Many office and signage displays carry an on/off timer in their settings menu, and some interactive boards have one too. It is a five-minute demo check: find the timer entry, set an on-time for tonight, and watch what happens.
Plug-in timers fill the gap. A mechanical 24 hour timer switches in 15 minute steps, which is coarse for a changing closing time; a digital 7 day model takes a daily on/off program and handles a different schedule each day. Safety note: the timer must be rated for the screen's load, and any wiring fixed behind the wall belongs to an electrician.
Then run the mains test. Plug the screen into the timer, cut the mains, restore it. Some displays come back in standby and wait for a button press. If yours does, look in its menu for the setting that powers the screen on when mains returns; if there is no such setting, that screen needs its own timer and the plug-in timer belongs on the player instead.
A small dedicated player fits this route well: power arrives, the player boots straight into its locked-down playback app and the loop starts, the pattern described in a locked-down signage player that boots straight into playback.
Autoplay and loop, with no subscription
Whatever plays the loop has to start itself. On our panel-mount signs the playlist lives on microSD or USB and autostarts at power-on; the playlist autostart setup is a documented walk-through, and you can choose which screen shows first at startup so the first thing the street sees is the offer. Software is included with the hardware, so there is no subscription. When mains returns after an evening power cut, the player is designed to start its playlist again. A cloud player wants a network and a subscription; an offline player wants neither.
Set the loop to the evening: 30 to 60 seconds per slide is normal window pacing.
Brightness behind the glass
Night inverts the usual brightness question. The street is dark, the glass is a mirror, and every light left on behind the screen reflects in it and washes the picture. Kill the shop lighting behind the display after closing, clean the glass inside and out, then judge the picture.
Our panel-mount signs run 250 to 400 nits standard across the range, which holds up in a dark window with the interior lights off. A window facing a lit street, headlights or a crossing wants more: take the sunlight-readable brightness option, the higher-brightness grade. Judge it on site at dusk, with the street as it will be when you open the loop.
Recommendation
Recommendation: Size the board for the room and give the window its own screen. For a 13 ft table, a 75 inch touch board covers slides to 21.5 ft and detail to 9.2 ft, and the big canvas earns its space for drawing and annotating together; if budget is tight, about 45 inches of diagonal is the slide floor at that distance. For the window, hang a small offline panel-mount sign from 15.6 to 23.8 inches behind the glass, load its playlist on a card, set autostart, and let a plug-in timer or the sign's own menu run the evening hours; that route carries no subscription. Take the one-device path only if the board's spec sheet names built-in signage playback with loop, scheduled and interval modes, and only after the mains-return test passes.
What to ask for
- The spec-sheet words: built-in digital signage, loop, scheduled and interval playback. Words absent, feature absent.
- An on/off timer in the display's settings menu, and the mains-return behaviour, both of which you should ask to see working on a demo unit in the showroom before you order.
- For the player route: the board's HDMI input, confirmed at the resolution you run, typically 1920 x 1080.
- For the window sign: panel size from the example above, the brightness grade matched to the street (sunlight-readable for a lit one), a no-touch panel, and autostart confirmed before the order.
- From us: our display range includes larger wall models through 75 inches, quoted per project, with software, ports, power, orientation, rating, lead time and warranty confirmed in the quote. The small retail displays for counters, shelves and fitting rooms top out at 23.8 inches, are built to order about 2 weeks, carry a 3-year parts and labor warranty, and include the software with no subscription.
Questions
Does the shop window screen need touch?
No. A night loop is watch only: the passer-by never touches the glass, so a touch layer is cost and one more failure point behind the window. Choose a no-touch panel for the glass and keep touch on the meeting-room board, where the drawing and annotating happen during the day. Touch earns its cost only where hands meet the screen.
How long should each slide run in a window loop?
Plan 30 to 60 seconds per slide. A passer-by decides in seconds whether to keep looking, so put the offer headline on the first slide and hold a full loop under about 4 minutes so the same viewer sees it again without a long wait. Four to eight slides at that pace fills an evening without wearing thin.
Can I use the meeting room PC for the night loop instead of a player?
Yes, if two things hold. The PC must wake or power on on a schedule, and it must start the slide show by itself at login so nobody clicks anything. Most PCs can wake on a timed event set in their firmware settings. Run the whole chain on a timer for one evening before you mount anything on the glass.
Planning information, not legal or engineering advice. Rules differ by place: check codes and permits with your local authority and your licensed trades.