Actually this is quite normal but a common question asked by customers that have recently had an air source heat pump installed and noticed water coming out of the bottom.
To most users this would look like a leak, a problem, a bad thing. And most would call their supplier for advice and a tech to visit and repair.
But heat pumps in their nature let water drop from the bottom via an outlet. this is normal. Heat Pumps take heat and moisture from the air like an air conditioning unit. That moisture is not required so let out through the bottom.
Quite normal. Nothing to worry about.
If your friends want a heat pump go to https://www.aquawarehouse.co.uk/energi-heat-pumps
