I have an LG 2.5 Inverter split system downstairs, and 1 hp window type upstairs. The window type usually only needs the filters cleaning which I do myself 3 monthly. The split system I have serviced every 6 months. RTC strip down the indoor and outdoor units, clean all filters, check all connections and blow through the drainage system to clear any mould. The humidity here can cause the drainage system to get blocked by mould. The outdoor power unit is checked for leaks and particular attention is paid to cleaning the heat exchangers which can make the unit run too fast if dirty. The whole service takes about 90 minutes. RTC arrive at the appointed time, have all the right tools, and clean as they go, giving everything a final clean when they finish. I provide cold drinks for the two-man team. The whole service costs me 560 peso, with a BIR receipt issued. Considering the split unit cost 48,000p new, the 560p is money well spent.