Always choose a heater size with the appropriate heat output for the mounting height and area to cover. By selecting a smaller unit, you may require more heaters to get the same amount of heat output. If you are choosing a dual element unit for aesthetic purposes, you will be concentrating more heat into a tighter space. Again, this may mean that you will possibly require more fixtures to provide total coverage of your area. Patio heating is often a compromise between functionality and finding the desired look.