Difference between a storage heater and an instant heater

A storage water heater or hot water system (HWS) is a domestic hot water appliance that uses a hot water storage tank to maximize the water's heating capacity and provide instant hot water delivery.Traditional storage water heaters use a variety of fuels, including natural gas, propane, oil, and electricity.Less conventional hot water technologies, such as heat pump water heaters and solar water heaters, can also be classified as storage water heaters.

Difference between a storage heater and an instant heater 

The primary difference between a storage heater and an instant heater is that a storage system can deliver hot water instantly, and an instant heater takes an amount of time to heat the water first.As the name suggests, tankless water heaters provide hot water almost instantly.There is hardly a 1 or 2 minute heating time before hot water is ready to use.But given the low storage capacity of these types of heaters (up to 5-6 liters (1.3-1.6 US gal) at a given point in time), you can't expect to fill a barrel or drum at the same rate.They are significantly more expensive than storage heaters, but last longer.This averages out to 15-20 years.Tankless water heater provides water as needed.No heat loss and cheaper than storage water heaters.Storage heaters are not as fast as instant versions because they require heating a large tank of water and then storing it for later use.Storage tank water heaters are ideal for large volumes of water (large tanks store approximately 75 US gallons (280 liters)) and are popular due to their low upfront cost and average lifespan of 10-15 years. But these systems are the least energy efficient and expensive to run in the long run.They also require more installation space.

Fossil fuel fired water heaters

Natural gas and propane storage water heaters heat water in the same way as a gas or propane burner located at the bottom of the storage tank.The oil storage water heater has a similar configuration, igniting the vaporized mist of fuel and air by electric spark.Emissions from fossil fuel water heaters are removed using various ventilation techniques.Atmospheric ventilation systems use room air as combustion air and exhaust.Exhaust gas is discharged through the exhaust flue under the action of buoyancy generated by combustion.Power exhaust models operate similar to atmospheric exhaust systems, but add an exhaust fan to help expel combustion gases.Direct-vent systems do not use indoor air for combustion; instead, buoyancy forces outside air through the water heater combustion system, eventually venting the combustion gases to the outside.Powered direct ventilation system includes exhaust fans to help expel combustion gases.