so i could get away without a pump if it somehow gets hooked up to the waste for the bathroom.
otherwise some type of pump will be in my loft space
Yeah. Basically, if the refrigerant pipes from the AC unit need to go up at any point (i.e in to your loft) then a pump will be needed to push the condensate away. Here is a picture of my master bedroom (in the loft of my house - its a town house by design). Ideally it would have been easier for the unit to go on the wall above the headboard of the bed, which is an outside wall and would mean the condense would have naturally ran away due to gravity.
The installer advised not to put it on the external wall as it would be blowing over us in bed, potentially giving us a sore throat. The original suggestion was to put it above my chest of draws but that required a pump as the pipe work would of had to go in to the small loft space above and then out the external wall.
I opted for it's location below as my friend pointed out there might be a drain in my hot water tank cupboard (behind where the AC unit is), and he was right. The hot water tank has a pressure relief valve that is piped in to waste pipe which the AC installer was able to tee in to.
This is directly behind the AC unit. Within the larger bit of trunking, the copper refrigerant pipes go up in to the loft and out the external wall of my house. The small white plastic pipe that comes out the bottom is the condense line.
Close up of where it enters the drain.
I also have two rooms below my master bedroom at the back of the house where the units are like this (this is my office).Both the window walls did not have enough space to fit the unit (its about 800-900mm wide). The condense for these just go out the side of the house and straight down in the trunking that the refrigerant pipes are in.
It is not ideal have them butted up a wall like this (apparently) but they still work very well. My units are way over spec'd for my little bedrooms and I often just leave both the lower floor bedroom doors open which helps keep the rest of the house cool.
An outside view so you can see what to expect from the trunking. It's not pretty but I don't think it looks too bad.