You can mount them on any flat roof or patio cover. You can put units on more than one roof area to gain the desired total size. A new structure can be built specifically to accommodate the solar heater. The heater unit must be positioned higher than the pool equipment, so that it can gravity-drain when it is not in use. Check for shading of the heater location.
Direct sunshine hitting the heater unit is what produces heat for the pool.
Even on very hot days, a solar heater won't warm the water if it is shaded. Trees may need to be trimmed or cut. There is usually more than one way to accomplish this. If the pool equipment is not right next to the structure where the solar heater will be installed, the feed and return pipes are typically put underground. W. Bell Dr.