Preformed prepaid maintenance on two Lennox split heat pump units, model and serial numbers match in the system. Replaced 2 filters down stairs. Upstairs units need 14x20 MERV filters replaced. Crawl space unit needs new 20x25x5 filter replaced as well. Cleaned coils and cleaned drain lines. Checked unit amp draws slightly higher than unit required running and start amps. This can cause compressor ware. And surging on the compressor. Units would both benefit from a compressor saver kit (99.00 ea.) to allow normal amp run to compressors. Inspected both systems air handler units and found substantial growth forming inside both units. This is an air quality issue. Both are nits would benefit from whole system air purifiers. These units would kill pre-existing growth and prevent any new growth from occurring. Would also kill pathogens to small for the normal filter to catch. Other than stated in this invoice all other systematic components are working properly at this time.