Winters are here, and so is the demand for geysers. While a geyser is a very useful product for commercial and domestic purposes, it can be quite tricky and frustrating at times to buy one. There are three types of geysers available in the market.
- Gas Geyser
- Electric Geyser
- Solar Geyser
While electric geysers are one of the most common types we see in our everyday lives, solar geysers have been on the rise for the past few years. Instant water heaters are the best option for electricity saving, however, they increase the load on your electricity distribution. However, most small storage water heaters do not provide sufficient hot water in most conditions, and in fact, in colder cities, the instant water heaters do not work effectively as the rate at which they heat water is very low. But a gas-based water heater provides a fast and continuous supply of hot water for a long time while saving energy at the same time.
Comparing the heating rate
Most regular water heaters have a 2kW or 3kW heating element. Whereas an instant electric water heater has a 4kW heating element.
The table below shows how they compare in terms of the rate of heating:
| Heating Element Wattage | |||
| 2 kW | 3 kW | 4 kW | |
| Time taken to raise the temperature of 6 liters of water by 25 degrees | 5.25 mins | 3.5 mins | 2.63 mins |
This means that even with the instant electric water heater, it will take about 30 seconds to heat 1-liter of water by 25 degrees. If you are in a place with very cold temperatures then it would take more than 30 seconds to heat just 1 liter of water to the temperature good for bathing. As compared to it, gas water heaters are available with an equivalent of 12 kW so it will take heat water 3 times faster than an instant electric water heater, hence it would take just 10 seconds to heat 1 liter of water by 25 degrees. Meaning that you’ll get hot water much faster.
Compare the cost of heating
Gas water heaters are 85% energy efficient. This means that 15% of heat is lost but still 85% is used for heating water. Since all the heat is used up to heat water, an electric instant water heater is close to 100% efficient. If we compare the cost of raising the temperature of 6lts of water by 25 degrees, the cost comparison is shown in the table below:
| LPG | PNG | Electric | |
| Unit Definition | 1 Cylinder (14.2 kgs LPG) | 1 SCM | 1kWh |
| Energy (in Joules) per unit | 654620000 | 41868000 | 3600000 |
| Energy (in Joules) per unit factoring efficiency | 556427000 | 35587800 | 3600000 |
| Units Required to heat 6 lts of water by 25 degrees | 0.001132224 | 0.017702696 | 0.175 |
| Cost per Unit (in Rs) | Rs 423 (Subsidised), | Rs 23 | Rs 5 |
| Rs 750 (Un-Subsidised) | |||
| Cost of heating 6 lts water (in Rs) | Rs 0.48 (Subsidised), | Rs 0.41 | Rs 0.875 |
| Rs 0.85 (Un-Subsidised) |
This shows that a gas water heater is at least 50% cost saving as compared to an electric water heater if you have subsidized gas or PNG.
A gas water heater is 85% efficient, then how is it energy efficient?
Gas is a primary source of energy. It is extracted and used as is and the only losses there are, are during transportation and they are minimal. Whereas electricity is a secondary source of energy. It is generated using coal or other forms of fossil fuels. There is a possibility of inefficiencies in the transmission, generation, and distribution of electricity. It is said that there are 15-30% losses in India, in general. And this is why using gas for heating water is energy efficient as using electricity in itself is not as good as using the fuel directly.
How does Gas Water Heater work?
There is a very simple technology behind the working of a gas water heater. The water moves through a pipeline which passes through a heat exchanger which has a water pipe covered with fins and there is a gas burner below it. Then with the help of inbuilt batteries, an electric impulse is created which in turn ignites the gas burner. The flames heat up the fins which in turn heat the water. And the hot water is obtained from a hot water outlet. The system starts up the moment you switch on a tap and switches off immediately after you close the tap.
