If youre spraying paint outside yr transfer rate of paint to work is gonna be really low... id say 70% at most, with the rest blowing down the road. I tried spraying emulsion inside a room once, well actually it was the new spray shop in our workshop, with a Kremlin air assisted airless system which is about as good as you can get and ended up going My point is you're gonna use more paint if you spray. Not to mention lose a load more if youre spraying outside. Then youve got masking up time, gun set up time, which can change from one batch of paint to the next to eliminate your tail lines (unless you want tartan paint when you cross-coat).
On the upside once youve masked up you can go like a bat out of hell, Id recomment any of the siphon systems, just make sure you're hoses are long enough to reach your furthest point.
Im assuming you're spraying onto a flat surface? If its something like tyrolean watch yr shadowing, if its dashed, dont spray and get someone in!
However the equiptment is dear, A setup for what you want to do is gonna cost you about 2k for the gun, pump and short hoses, then you need longer hoses to get up the top of the house unless u wanna put tower up n cart the stuff up!
I should point out that inside the house youre gonna wish you rollered it.. doesnt matter which gun you use, its gonna go everywhere, At least 10%-45% of your material is gonna end up floating in the air as overspray, coating anything you havent masked up, In bigger rooms this can be a problem as where you started will be dry by the time you get to the other end (faster that you might think as we are aerating it drastically by atomising it for spray) and if overspray gets on it you can end up with a nice suede feel to your finish.
Not trying to put you off but unless you get decent gear a shed load of masking up stuff and about 30% more paint than youd need than by roller.... i'd sack it and roller it on!
