Depends on the application. Assuming that the inaislltng entity properly selects the heater for the expected load (tank type and tankless water heaters do come in various sizes for various water heating loads), the main advantages tankless heaters have over tank type heaters are an endless supply of hot water (no more hot to cold showers) and energy efficiency. The main disadvantage tankless heaters have relative to type type is initial installation cost is 20% to 40% higher than the tank type for a oil/gas fired heater.While gas/oil-fired tankless water heaters were considered maintenance head-aches (hard to find technicians knowledgeable about the heaters) they are becoming more common in residential applications (help is on the way). For residential applications, most of the energy expended (>50%) in a tank-type heater is used to compensate for convection heat losses when the heater is in stand-by mode (no water users). These convection heat losses only heat a typically unheated space such as a basement; thereby wasting the heat. The tankless heater does not have these convective losses therefore does not waste this heat. If the application has a continuously circulating hot water loop (pumped loop), as is the case in many commerical and selected high-end residential applications, the tank type water heater is used. The tank acts buffer to even out variable loads and reduce the size of the primary heating equipment. If energy source is electricity, the clear choice is the tankless type as the heater may be installed at the use point. No waiting for the distribution piping to warm to the hot water temperature. Also the electrical tankless water heating is more thermally effective than the tank type.
Depends on the application. Assuming that the inaislltng entity properly selects the heater for the expected load (tank type and tankless water heaters do come in various sizes for various water heating loads), the main advantages tankless heaters have over tank type heaters are an endless supply of hot water (no more hot to cold showers) and energy efficiency. The main disadvantage tankless heaters have relative to type type is initial installation cost is 20% to 40% higher than the tank type for a oil/gas fired heater.While gas/oil-fired tankless water heaters were considered maintenance head-aches (hard to find technicians knowledgeable about the heaters) they are becoming more common in residential applications (help is on the way). For residential applications, most of the energy expended (>50%) in a tank-type heater is used to compensate for convection heat losses when the heater is in stand-by mode (no water users). These convection heat losses only heat a typically unheated space such as a basement; thereby wasting the heat. The tankless heater does not have these convective losses therefore does not waste this heat. If the application has a continuously circulating hot water loop (pumped loop), as is the case in many commerical and selected high-end residential applications, the tank type water heater is used. The tank acts buffer to even out variable loads and reduce the size of the primary heating equipment. If energy source is electricity, the clear choice is the tankless type as the heater may be installed at the use point. No waiting for the distribution piping to warm to the hot water temperature. Also the electrical tankless water heating is more thermally effective than the tank type.
Great job Wendy!