Gas-Fired or Electric? What's Best for My Needs?
Every day someone contacts our company asking us for an electric tankless water heater. What we notice is one common misconception. Almost everyone inquiring about an electric tankless heater wants to install it as a replacement for an existing electric tank-type water heater. We have found that most people are visualizing that they simply mount the new electric tankless heater on the wall and plug it into the pre-existing wiring from their old tank type heater. This is simply not a correct assumption. For an electric tankless heater to supply hot water at the required GPM (Gallons Per Minute), a much larger amount of electricity is required. The amount of electricity required is huge when compared to typical appliances. In fact, an electric tankless hot water heater’s electricity requirements exceed the capacity of the typical American home. To find out the details, please read this report and comparison. We have taken the time to explain these energy consumption needs in an easy to understand way.
Early in our research, we extensively evaluated electric tankless water heater technology and chose to focus our efforts on gas-fired models. We decided that our company would not enter into the business of electric tankless heaters for a number of reasons. Without turning this article into a sales pitch, we will point out some of the same facts that resulted in our company’s selection of gas fired heaters as our product line.
Simply comparing our popular EZ DELUXE 4.0 GPM model to a similar but slightly smaller GPM capacity electric unit, one can clearly see the differences. (To be fair, we compare our EZ Deluxe to one slightly smaller and one slightly larger electric powered unit. The manufacturer’s specifications of the models used in this comparison are listed on their web site and we presume that they are accurate. However, we did not conduct tests on the specific electric models used in this specification comparison.)
As previously mentioned, please keep in mind that not everyone lives in a modern newer home, older homes typically do not have 200-AMP and larger electrical services and modern expandable circuit breaker panels. In fact a 300-AMP service is rare in a residential application. Some older homes have only 100-AMP services and in fact some small rural homes may still be operating on 60-AMP services which were typical before the days of central air conditioning and multiple baths.
OUR EZ DELUXE TANKLESS HOT WATER HEATER
Our 25 KW (85,000 Btu) EZ DELUXE gas fired tankless heater is rated at 4.0 GPM (at a 60 degree temperature rise. If the ground water temperature is the typical 55 degrees, this means that the maximum exit temperature will be 115 degrees at 4.0 GPM.) The EZ DELUXE requires only a simple 115-volt plug-in for the control-panel and fan motor that operates the direct vent system. It is fused for a maximum “overload” current draw of 115V 2-amps.
WE COMPARE OUR EZ-DELUXE TO A WELL KNOWN ELECTRIC TANKLESS HOT WATER HEATER
For this comparison, we selected two Stiebel brand “Tempra” electric tankless hot water heaters. The first example is a 24 Kw electric model that is rated at 3.3 GPM (Rated by the manufacturer at a 50-degree temperature rise. This means that if the ground water temperature is 55 degrees, the maximum exit temperature at 3.3 GPM will be 105 degrees) Ten degrees lower than our EZ Deluxe model
The manufacturer specifies a 300-amp minimum service. (Size and capacity of the user’s electrical panel) A supply of 240-volt electricity at 100-amps, and installation of two 60-amp circuit breakers with two runs of #6 copper wire.
NOTE: Even on a 300-amp service panel, this is no small load.
This same manufacturer offers a 36 Kw model rated at 4.9 GPM (Again it is rated by the manufacturer at a 50-degree rise with a typical exit water temperature of 105 degrees). To achieve this 4.9 gallon rating the manufacturer specifies 150-amps of 240-volt electricity, three 60-amp breakers and three runs of #6 copper wire. Certainly in many older homes, electrical service upgrades would be required before these units could be installed. At what expense, we cannot determine. Some upgrades may be relatively inexpensive, some may be more elaborate and the costs can be substantial.
COMPARING (ONE RUN) OF 240V - #6 WIRE TO A TYPICAL EXTENSION CORD
WHAT DOES THIS REALLY MEAN?
Another way to explain the electrical requirements of an electric tankless model is to visualize how much electricity is required in comparison to appliances that are more familiar to the average home owner. For example: The 36Kw electric tankless model that delivers 4.9GPM at a 50 degree rise is using 36,000 Watts.
- 36Kw is approximately the same amount of electricity required to run 30 coffee makers. All of them turned on at the same time.
- 36Kw is approximately the same amount of electricity as required to simultaneously run 60 average sized microwave ovens turned on the high cook setting.
- Or maybe you are familiar with the 5,000 BTU window type air conditioners. (The one-room variety that sell for about $150.00 in the big chain stores) Imagine that you could run 36 to 45 of these air conditioners simultaneously to equal the current draw of this one electric tankless water heater.
- 36Kw is approximately the same amount of electricity required to run a Toyota Prius! This same 4.9 GPM electric thankless water heater is rated at 36Kw 240V and a 2001~03 Toyota Prius has a 273.6V motor that is rated at 33Kw.
HOW DO I KNOW THIS IS THE TRUTH?
We suggest that you do your own research and we believe that you will draw similar conclusions. Certainly there are applications for electric models and they work and people use them in their homes. Electric tankless heaters do save energy. Every tankless water heater saves energy as they only use energy when a hot water faucet is turned-on. Gas or electric models have no standby energy consumption and are therefore more energy efficient.
We know from experience that there are some homes that are best served by a gas-fired appliance. We feel that the vast majority of our present and future customers are best served by our specialized knowledge of gas models. We did this comparison to show that gas-fired tankless hot water heaters are more easily adaptable for the most number of users who typically are making a transition from a tank type heater. In fact, 99% of our customers are buying their first tankless water heater as a replacement for a tank type unit and may not completely understand the numerous differences in the technology and related energy requirements. For this reason, we feel it is in our best interests to concentrate on supplying our present and potential clients with one of the most informative and unbiased web sites on the net. We know we can’t sell a hot water heater to every person that contacts us or browses our website, but we are proud to be leaders in offering the American home owners up to date and easy to understand information.
For more information about how to select the proper size of tankless heater and the requirements of exhaust and intake air, please see our additional articles related to these subjects.
See our faqs page for everything you ever wanted to know about tankless heaters and then some.
Thank you for your interest in our products and we hope that we have helped you make an informed decision on selecting what type of tankless heater best fits your specific needs.