i DIY clean my own AC. i guessing the key to keep the FCU coil clean (as dont wait until the fin turn black/black/dirty due to dirt, dust etc... which stuck in the fin then clean, which is by then too late liao, will need those chemical wash but chemical wash use by vendor is alkaline which mean it corrosive to the aluminium fin, which is why you see bubbling (corrosion) when they spray at the aluminium fin ) Also if they use that, they need to really wash off the chemical So how often to DIY wash is depend on how often you use, like if on daily mean it need to clean every 2 to <3 per month, if on <3 times per week it my guess every 4 to 5 mth. Even if it look clean and shiny The reason is, like mine FCU, it look clean (i dont see any dust at the fin or blower ) but after washing and when i pour away the water which is collected from a pail as mine dont flow to the drain (as shown in picture) there lot of dust debris at the bottom of the pail Also to use the fan mode before switching off to keep the coil dry for at least 30min and use condensate table every 2 to 3 week (for me 3 tablet per 2 week or until i see the FCU is clear water then i need to add tablets. one of the pros when collecting water at bucket every 4th wash, i will remove FCU cover for a deeper DIY wash the chemical i use is ajax fabuloso, but supersteam 301 or 306, comstar coil is tested safe. but to confirm it yourself, cut some aluminium foil and soak it with the the chemical you want to use for your FCU for 24hr, if it stay the same, then it safe. those above contain, which i cant remember something that can remove dirt, dust, stain etc... and it aluminium safe for installed of my aircon. so far 1.4yr liao, still as cool, no leak, no condense at trunking (even when i on 17hr per day) so cannot fault them yet update: when i say FCU clear water, i mean my condensate tablet is green in color, so i can tell if the tablet already all dissolved or not. so clear mean need to add more condensate table after 3yr, i may get a steam cleaner from TB to try to clean the coil(not sure if it work). i have a round pin socket which can support 20amp as the electricians told me they use the wire can support 20amp. so watt should not be a issue, cause currently i using the socket for my induction, easily go to 3500watt for 1 hr cooking and the socket feel normal temp  

my real life example for me a room size of 5.5 by 2.9 and based on btu room calculator websites (https://www.calculator.net/btu-calculator.html) , 11k is enough, but in real life, i run 25c at speed 3, it take 7 to 12min for the operation to be off and if i set to 21c, even after 110min later (this is tested at night after 8pm), the AC is running full load cause operation light is still on operation light on as in starmex mean compressor still running full power 

a lot of country washing dont really take out blower unless it super dirty like few yr nv wash type.   by default other country normal wash is pressure wash with blower inside     my system 1 12k btu energy usage   me using starmex system 1 12k btu, MUY-GP13VF. this is based on agar agar MUY-GP13VF standby power consumption this will be the electricity i use per month on average 5 kWh over 3 month Water heater : switch on 10min per month AC: switch on every 2 times per month (35min cooling mode at 25c then before switching off i change to fan mode for another 35min) there no other devices that is using electricity so i am guessing the standby power consumption for my starmex system 1 MUY-GP13VF use around about 3kWh per month as such with this number is known, i will install a 2nd condenser. but it have to hang on the ac leadge wall and windows cannot be open fully first month (dec) higher due to renovations      afternoon I notice the aircon take much longer to reach 25c, I tested it 3 times in the afternoon to on ac, it take on average 20 to 50min to reach 25c (sometime fast and sometime almost 1hr and I forgot to see if it sunny or cloudy ) for night it take less then 13min to reach 25c ( for night I only managed to test once so result is once one 1 data) Also my room is pretty well insulated other then the Windows which I plan for adding sec glazing For afternoon why such long cooling down, my best guess is the sunlight heat up the wall and window which keep releasing heat. Also the room temp is much warmer and humid which I guess add to the cause. So if u are someone who one ac in the afternoon or 24/7 type, say if the btu calculator say u need 10k, get 18k model, else ur ac will be like mine who tale almost 1hr to cool to 25c Also my door I buy those cheap $10 bottom door seal and so far no leaking of cool air to the warm side aka no aircon side

oysters better or blue pill better?