Air tools are a good start, they are not expensive to repair either (but could be hard for you to test without an air compressor).

The other scenario we're dealing with is tenants with newborn children.We have two of those right now and we do our best to work around their schedule and work as quietly as we can.I do some of the work and I wanted to mention something about an air compressor I recently purchased. 

When the air compressor was not running I could hear bubbling in the hot water heater.It might be advisable to replace the hot water heater and dewinterize the system to check for leaks that maybe hidden behind walls and ceilings.

You will never achieve what  professional will but you can get an air compressor and a side nailer for 200 bucks.

Sprayers have tiny seals in the compressor and storage liquids have additives in them to condition the seals and protect the inner passageways through the compressor, as well as protecting bearings.

Then, it still always involves 2-3 trips to the plumbing supply store or Lowes.Table saw, chop saw, jig saw, roto-zip, rotary saw, 3 sizes of hack saw, sawzall, router, under door saw, bow saw, chain saw.....Battery drill, battery skill saw, battery flashlight.Many sets of drill bits and screwdriver bits, flat, phillips, star, hex, several pry bars, pliers, pipe wrenches, screwdrivers, wood chisels.......Tape, carpenter's pencils, utility knives, several sizes of tape measure, T-squares, and levels.....Buckets of plumbing tools, spare lengths of PEX, PEX fittings, PEX tool, PEX cutter, teflon tape, plumbers dope, under sink wrench......Electric plugs, GFI plugs, wall switches, wire nuts, wire strippers, and a new light bulb for every fixture in the house ebcause every one will be burned out......Compressor, brad gun, nail gun, finish nailer, roofing nailer, hardwood flooring nailer, assortment of nails, brads, screws, staples and the power stapler to go with them (both electric and pnuematic).Drop lights, halogen work lights, salamander heater, furnature dolly, saw horses, portable propane tourchSanders, 3 sizes, sand paper, power planer.....And there's more.

I guess just that and the pipe was went into the cistern and in the garage they had a compressor to pump the water into the house when needed. 99% certain if this was a game of chance."

They argue it is to keep temants from making frivolous maintenance requests but then they apply it towards a fridge compressor that breaks.  

Seems high but i'm sure that 10K is more than just the fan, compressor, handler etc.

An empty house is prime for the guys who steal the AC compressor outside and strip out the copper wire and just ruin your thoughts of leaving it empty for any time.