Solar hot water heater question and grey water irrigation
Can I use a drainwater heat recovery unit on a solar hot water heater? I want to be able to extend the heating capacity of my hot water. DH really wants a solar hot water heater. We have a south facing roof that backs up to an alley. I need the ability to occasionally take longer than normal showers. Normal is 4-5 minutes each for two people. Long is 20-30 minutes for one ( with multi-shower heads) plus 5-10 minutes for 2-3 others, but not simultaneously. A drainwater heat recovery unit was suggested to me on another forum, but I'm not sure they realized that we really want a solar hot water heater. I'd also like to recycle my grey water for irrigation. Any advice?