Acer H6815BD

I was looking for a cheap 4K projector to use in a classroom - this requires a few compromises, such as partially darkening the room and placing the projector about 4m from the wall to get a big enough image - the zoom capabilities are very good limited

I was looking for something I could place 5 m away from the wall and this projector gives me a nice image about 3 meters wide. I find it disturbing that it comes with a USB-A (power only) plug in the back but Chrome Cast cannot be powered by it because the current erogated is too low. The fan is very loud, even in ECO mode. I assume that is a problem with all the projectors because they are very inefficient machines and need to get rid of a lot of heat. So, you need good speakers and keep the volume quite high. Because I am not an expert in projectors, I cannot tell if this one is good or bad. I will keep it because I cannot find anything else that I am sure works at a 5-meter distance from the screen.

The projectors image quality is great, there is a lot of agjustment options and modes to use it in. If it was just about the image quality I would have kept using the projector.

Unfortunately both models I tried had an audible power supply buzz, one even when the model was turned off. This is not suitable for home cinema setups where people are sitting within 2 meters of the projector. The medium to high pitch noise will cut though most movie audio and doesn't really fade into the background.

Another minor point is that the projector runs quite warm, this and the fact that the fan runs after the unit has turned off is what made me check if the projector actually has an LED lamp. Which a google search revealed to be false, the projector uses a standard lamp.