Hi, my new washing machine + dryer manual states that the outlet must either be placed on the sink that is 80cm above ground or a standpipe




but I think it'll look ugly and don't want the hassle of hiring a plumber to do it, this is my current way of connecting the outlet drain hose, is this still ok?

It's ok.
The guide i think is for maximum height of pipe or capability of the built in pump.

As long as you raise up the hose before it goes down it's fine. What you've done as in the photo is fine. My two washer dryer at my condos are set up like that without standpipe

What's the reason behind it?
Is it to keep the pipe filled with water so that cockroach cannot enter from the outlet?

the one u posted is just okay...
acceptable..

sometimes the guide given cannot follow 100% in real situation...
minor adjustment is required...

The standpipe is to provide some height to prevent the washing machine from re-sucking up dirty water in the drain. This is important if your waste pipe dangles into pipe that might become full of dirty water.

Your washing machine already raised the hose by fixing it to the side, so they have actually settled that problem for you already.

Because urs is high flow discharge pump so the standpipe is to ensure the drain dont overflow before existing water (before new drain water comes) drain off in time..in other words its a buffer space

May I know how to construct a standpipe? My current stand pipe height is just 10cm high.

Do I just buy a longer pipe to join it with glue, or need to add bracing for vertical stability? The former i can DIY, but the latter I think will need outsource due to drilling on tiles.

oh i never knew the reason behind it.