A tankless water heater has made it possible to avail hot water instantly while saving more on fuel costs as compared to other types of water heaters. But, it always remains in our mind to find out how much propane does a tankless water heater use.
Rightly so, energy cost is one of the most important factors you consider when choosing the best heater for your needs. We all know that it adds up to your utility bills, and so the more you can save on it, the better.
More importantly, it’s not about the cost, but being responsible citizens, we all should use the natural resources maturely. For that, the first step involves knowing how much propane does your water heater uses.
For those who have tankless propane water heaters, this article is going to inform you about how much the gas is used by one heater.
What is the propane consumption of a tankless water heater?
Remember that tankless heaters are said to be more efficient in terms of energy saving. We are going to find out how true it is anyway.
When it comes to gas consumption, there are a few factors involved that we have to analyze. Let’s discuss them one by one.
Propane tankless unit size
There are various sizes available in this regard. The bigger the size you have, the more consumption will be there. For example, a 53,000 BTU tankless heater will use more gas than a 100,000 BTU heater.
Hot water generation time
How much time the heater is functioning will heavily affect the gas usage. For example, if the heater is running for 20 minutes a day, it will require less gas than a heater running for an hour a day. Usage hours are determined by Gallon per Minute (GPM).
Typically, for laundry, the usage lies within the range of 2-3 GPM, whereas, for the shower, it lies between 1.5-3 GPM. This can vary subject to the kind of work.
Groundwater temperature
The temperature of incoming water also heavily affects how much the gas will be used to heat up the water. It is obvious that if the incoming water is cold, it will require more heat.
Location is crucial here. If you live in a cold region, your incoming water is likely to be cold as well.
Calculating propane consumption
The above factors help you define and calculate the propane gas usage by the tankless water heaters.
In a nutshell, calculation requires three things. These are:
- The tankless heater capacity in BTU
- The energy efficiency
- How long you are going to run it in a day
Talking about the low end, the propane tankless unit size of 53,000 BTU with 5.3 GPM, the yearly propane usage by the heater for running 20 minutes a day will be 74 gallons, for running 40 minutes a day will account for 148 gallons, and for running sixty minutes a day will result in 223 gallons approximately.
On the other hand, for an average tankless unit size of 100,000 BTU with 10.2 GPM, if we operate it for 20 minutes a day, the propane usage will be 140 gallons per year, 280 gallons for running the heater for minutes, and 420 gallons for running the heater for 60 minutes a day.
Talking about the high end, with a unit size of 199,000 BTU having 11 GPM, it will need 270 gallons of propane if operated 20 minutes a day, 557 gallons for 40 minutes of running time, and 836 gallons per year for running 60 minutes a day.
As said earlier, the gas consumption relies on several elements, and we have seen that if you increase the tank size or the running time, the gas usage will also be increased.
Conclusion
In terms of energy efficiency, tankless water heaters are considered the best. Considering the per year consumption of propane by a tankless water heater, as we have discussed above, it is proved to be right. The usage will not be the same for all, as it matters on a few factors, such as the tank size, hours of usage, and water heater capacity.
You can rest assured tankless water heaters are reliable and long-lasting. As for how much propane does they use, now you know about it.