Electric heaters provide spot, supplemental, or primary heat. Unlike natural gas or liquid propane (LP) heaters, they don't produce any fumes or VOCs, so they can be safely used indoors without the need for venting. Floor heaters as well as wall and ceiling heaters supply extra heat to areas where space is limited. Wall and ceiling heaters can also be used to provide primary heat in large areas like warehouses and garages where central heating is not typically installed. Baseboard heaters can act as a primary or secondary source of heat for small areas and rooms. Plenum heaters provide warmth to concealed or difficult-to-access spaces. Heating cables prevent pipes and roofs from freeze damage. Portable heaters may be moved from space to space wherever heat is needed. Spa and hot tub heaters keep tubs a comfortable temperature.