Loose tube collectors:
Provide room for contraction and expansion, which reduces the risk of leaks
This also leaves room for tubes to separate; debris can become trapped between the collectors and the roof, reducing their protection against wind.
Tube-and-web collectors:
Provide room for contraction and expansion, while providing maximum surface area
The flutes found between each tube provide more surface area, thereby increasing the size to energy ratio with each panel. More surface area = more heat, which provide warmer pool temperatures during colder months.
The difference between these styles is what we like to call “gloves vs. mittens”. When you wear gloves, your fingers are separated, which provides more opportunity for body heat to escape. When you wear mittens, your fingers are kept together, which promotes more body heat, and leaves less room for body heat to evaporate or escape.
Loose tube and tube-and-web collectors work under the same premise. Loose tube collectors operate much like that of the glove. Loose tubes helped to address wind load, but energy escapes or evaporates between the tubes. Tube-and-web collectors act as mittens; each tube is connected to the flute (or webbing). This means the energy you collect is less likely to evaporate or escape and the system will be more effective at warming your pool.