Should you lower the temperature? This means you will probably save money, decrease strain on tank, eliminate scalding hazard.
Or should you raise the temperature so each shower uses less hot water. (The tank yeilds more hot water since
more cold would be mixed with the hot)
Typical bath/shower is 104°F.
To save money and energy in a home that has small to normal usage, Then lower temperature is better because water heater has less standby loss,
resulting in reduced energy consumption. BUT... .... there are too many factors to make a reliable estimate that applies to everyone.
The theory behind this: All hot water that is consumed is replaced by cold water
that must be heated to the set point, and then kept hot until next
usage. Lowering temperature means less energy consumption duning the standby hours when tank is keeping water hot.
If you have home-or-apartment with high consumption: Then higher
temperature setting might be better so occupants don't run out of hot water.
The conclusion is: The temperature-setting issue boils down to standby loss vs
consumption. And that's where the issue becomes behavioral, and
then it becomes impossible to weigh all the factors needed for reliable scientific data that covers everyone.
Logically however, if you use less hot water, then the temperature setting can
be lower. This would apply except maybe laundry-day when you might want 135 degree water to
kill bacteria when washing clothes. Or you you might wash clothes in cold
water because it's better to co-existing with bacteria, unless you work
at a hospital or your immune system is compromised by disease?
My experience: Over the past 2 years, I accidentally discovered real-world proof that
behavior is the most important factor in hot water cost.
I put a meter on my electric water heater. And then my timer is run
some months, and the timer is turned off on other months to watch what
happens.
Does a water heater timer save energy? Yes, but not exactly the way you
expect. When using a timer, the hot water is rationed and occupants
(myself and my wife) know when hot water is available. As a result, our
consumption of hot water declines with shorter showers, and hands
washed with cold water instead of waiting for hot.
When the timer is off, and hot water is available any time, then
consumption increases. And the difference shows on the meter. Gradually
over time, more and more hot water is used after the timer gets turned
off: proving that behavior is a major factor, at least at our home.
Meter on water heater
The Kwh meter is din rail mounted inside enclosure.
Records
billable power usage in Kwh. Multiply by rate you pay per Kwh to get
monthly/ yearly cost of running electric water heater.
Install meter on Gas water heater
Record exact usage of BTU of gas appliances.
3/4" pipe thread connections. Use yellow teflon tape or gas-approved
sealant.
No excess tape or sealant inside pipe. Use black pipe or yellow flex
line. Keep pipes clean during assembly.
Install in vertical position with inlets pointing up as
illustrated.
12.2" Tall x 8.5" Wide x 11.2" Deep
No power source required
Digital readout in cubic feet
Remote Readable option (pulse output) using EKM-25IDS
Integrate with your home-automation module, zwave, wifi, insteon.
Or use daily or weekly plug-in timer to set schedule.
Gas water heater timer adjusts dial on gas control valve, rotating
between ordinary thermostat setting and 'vacation' setting.
The
water heater is never completely off, so there is no short-cycling
issue when operation resumes, plus vacation mode at 50° prevents water
heater from freezing.
No-tool installation. Works with older style
mechanical thermostats, and newer Honeywell thermostat, fitting both
propane and natural gas heaters.
Meter on water heater
Install meter on Gas water heater
