Question:
Bottled water: Purchase price: $2.50 per litre ? Environmental cost: mucho plastic and transport costs. Bad, bad, bad.

Answer: Summary: Mains water: $0.0015 per litre Dehumidifier: $0.152 per litre plus set up cost worth 200,000 litres of mains water that would take 109 years and $30,400 of power costs to recover at 5 Litres a day. Rain tank: Free(ish) plus set up worth 1,000,000 litres of mains water which would take AT LEAST 6.25 years to recover.

So you are quite correct. By these calculations, dehumidifiers suck.

Mains water by far is the cheapest, healthiest and most useful and convenient way of getting water.

While we have readily available water that is