I went to the "chain" pool store and they are selling heat pumps for AG pools. I asked a question on how do they work and I kind of got an answer that did not make sense.

I have central air in my home. I was told I need to have this heat pump connected to my heat exchanger portion of my HVAC system. This to me does not make sense. If that was the case that means the only time I would heat the pool would be when the a/c is on.

So how do these work?
Does this connect to my HVAC system in my home?
Is it a DIY install?
Is it worth the cost for a 7,600 gallon pool here in New England?