Save Money Or Lose Money By Changing Hot Water Heaters ... Check Here

The table below was calculated form the average energy factors for 6 types of hot water heating systems. Some were tankless also called on-demand heating or instantaneous heaters and others were storage tank heaters as you will see. The important point to bear in mind in the table that follows is this ...

We are comparing averages.

For example the average energy factor rating for an electric on-demand water heater at 0.99 is considerably higher than the average rating for a storage tank heater using propane which is rated at 0.56 (see table below). If you wanted to compare other values you would need to use the formula developed on the previous web page for each individual comparison of water heating sytem . However if you upgrade to an energy factor rating better than average your cost will always be more favourable than for the average.

Type Of Heater	Energy factor rating average
Oil Storage tank heater	0.59
Storage Propane gas heater	0.56
Storage hot water heaters ... gas	0.56
Storage Dual gas heater ... gas or LPG	0.57
Tankless hot water heaters ... gas	0.75
Storage Electric heater	0.89
Tankless hot water heaters electric	0.99

Example of water heater changed status

Refer to the table below (blue line). You presently have an average rated electrically heated storage water heater. You install a new average rated tankless natural gas hot water heater ... your energy bill will drop from $100 to $48.81. If your old bill was $200 then the new bill will be $97.62. In all cases it is assumed that the duty is identical ... in other words you want to heat the same amount of water by the same temperature difference.

On-demand heaters are another term for tankless or instantaneous heaters. I've just interchanged the words to make this point

Your NEW water heater	Your OLD water heater	Your OLD cost/yr	Your NEW cost/yr
Oil storage tank heater	Propane Storage heater	$ 100.00	$ 71.04
Oil storage tank heater	Natural Gas Storage heater	$ 100.00	$ 110.16
Oil storage tank heater	Natural Gas Instantaneous heater	$ 100.00	$ 147.53
Oil storage tank heater	Electrical Storage heater	$ 100.00	$ 72.02
Oil storage tank heater	Electrical Tankless heater	$ 100.00	$ 80.11

Propane Storage water heater	Oil Storage tank heater	$ 100.00	$ 140.77
Propane Storage water heater	Natural Gas Storage heater	$ 100.00	$ 64.49
Propane Storage water heater	Natural Gas Instantaneous heater	$ 100.00	$ 207.68
Propane Storage water heater	Electrical Storage heater	$ 100.00	$ 101.38
Propane Storage water heater	Electrical Tankless heater	$ 100.00	$ 80.11

Natural Gas Storage water heater	Oil Storage tank heater	$ 100.00	$ 90.78
Natural Gas Storage water heater	Propane Storage heater	$ 100.00	$ 64.49
Natural Gas Storage water heater	Natural Gas Instantaneous heater	$ 100.00	$ 133.93
Natural Gas Storage water heater	Electrical Storage heater	$ 100.00	$ 65.38
Natural Gas Storage water heater	Natural Gas Tankless	$ 100.00	$ 72.72

Natural Gas On-demand heater	Oil Storage tank heater	$ 100.00	$ 67.78
Natural Gas On-demand heater	Propane Storage heater	$ 100.00	$ 48.15
Natural Gas On-demand heater	Natural Gas Storage heater	$ 100.00	$ 74.67
Natural Gas On-demand heater	Electrical Storage heater	$ 100.00	$ 48.81
Natural Gas On-demand heater	Electrical Tankless heater	$ 100.00	$ 54.30

Electric Storage water heater	Oil Storage tank heater	$ 100.00	$ 138.86
Electric Storage water heater	Propane Storage heater	$ 100.00	$ 98.64
Electric Storage water heater	Natural Gas Storage heater	$ 100.00	$ 152.96
Electric Storage water heater	Natural Gas Instantaneous heater	$ 100.00	$ 204.86
Electric Storage water heater	Electrical Tankless heater	$ 100.00	$ 111.24

Electric Tankless water heater	Oil Storage tank heater	$ 100.00	$ 124.83
Electric Tankless water heater	Propane Storage heater	$ 100.00	$ 88.68
Electric Tankless water heater	Natural Gas Storage heater	$ 100.00	$ 137.51
Electric Tankless water heater	Natural Gas Instantaneous heater	$ 100.00	$ 184.17
Electric Tankless water heater	Electrical Storage heater	$ 100.00	$ 89.90

The Energy Costs Used to construct this table were as follows ... refer refer energy cost page here

Energy Source	Cost per million Btu
Electricity	$34.52
Natural Gas	$14.20
No. 2 Heating Oil	$16.48
Propane	$22.02
Kerosene	$21.22

Formula For Heating Water In All Systems

Flow rate of water in any units (eg gallons per minute or litres per hour) x a constant number called specific heat x the number of degrees the water must be heated by .... interpreting this in simple terms it means if you double the flow and want to keep the temperature increase the same (eg from 40 to 80 degrees) you must double the energy supplied be it in the form of electricity or gas or any other energy type. Alternatively if the flow is constant ( say 50 gallons per hour) and the final temperature is constant but the inlet temperature of the water is more or less then the amount of heat required to meet your specification will also be more or less.