Gas water heater is cheaper than electric water heater, but it is about twice as expensive as air to water heat pump water heater.
Due it needs to burn gas, even new ones can only be installed in the kitchen (theoretically balanced ones can be installed in the bathroom, but i is too dangerous). Now in commercial houses, most of them adopt the design of “open kitchen and secret bathroom”, the toilet is usually located in the middle of the deep direction of the building, which makes the distance between kitchen and bathroom longer, so the hot water pipeline is very long. The use of hot water in toilets also accounts for the majority of household hot water consumption. So most of consumers do not purchase gas water heater.
Analysis of Air to water heat pump water heater:
Heat pump is a device that uses electric energy to drive compressors or semiconductor heating chips to absorb heat from the environment. According to different working principles, heat pump water heaters are divided into compressor heat pump water heater and electronic semiconductor heat pump water heater.
Therefore, "the heat released by the heat pump is equal to the sum of the input electricity plus the heat absorbed from the environment". Its efficiency (termed "energy efficiency ratio", i.e. the ratio of output heat to input electricity) is always greater than 100. The actual energy efficiency ratio of small-scale domestic heat pump system is about 2.0-3.5. If it has waste heat recovery device, the energy efficiency ratio can be further improved. The present household air-conditioning system is a compressor heat pump system when heating. The difference is that HVAC is used to heat air, while heat pump water heater is used to heat water.
When the heat pump system works, one end releases heat and the other end absorbs heat. Therefore, the refrigeration and heating of heat pump are carried out simultaneously. Only when people use the heat of the hot end, they call it heating equipment; when they use the cold end, they call it refrigerating equipment; when they use the cold end and hot end, they also use the equipment called cold-heat combined supply.