Can you combine Energy Kinetics with Rheem hot water tank?

Roger

With a boiler and plate heat exchanger, a Frontier boiler will typically use about 10 to 12 gallons per month in the summer to provide hot water for an active household. The math supports this as well for Dept of Energy usage of 64 gallons per day with a 77°F temperature rise. 0.6 to 0.7 gallons per day might more normal with an indirect tank with a coil.

LRCCBJ

4 showers per day (15 min @ 2.5 GPM): 150 gallons

Dishwasher once per day: 6 gallons

Washing machine once per day: 8 gallons

Hand washing of dishes: 4 gallons

Your active household uses 168 gallons per day. 94 KBTU. 25G fuel oil per month. With an indirect tank, the usage is higher.

You might meet the Dept of Energy usage if you restrict everyone to a 5 minute shower. Good luck with that.

Charlie from wmass

I can't even restrict me to a 5 minute shower.

LRCCBJ

I suspect my numbers are conservative. Certain members of most "active" households take a 30 minute shower…………….or more.😣

Roger

Good points all around.

The numbers I reference are from decades of taking deep dives and analyzing actual usage in homes; 10 gallons per month is the norm, not the outlier. It's also important to recognize the temperature rise of 77°F. If incoming water is 40°F, no one is taking a 117°F shower (after the distribution piping heats up); the actual rise and energy usage is lower. 50°F incoming water and a 105°F shower jumps to about 90 gallons per day with the same fuel consumption.

Sure, there are very high use homes with drain down tubs, ski houses with a dozen people taking showers one after the other, 4+ teenagers taking long showers every day, etc. They will use more energy and enjoy that their hot water system can provide continuous steady and comfortable hot water.

LRCCBJ

10 gallons per month is effectively impossible unless you live by yourself and take 10 minute showers.

The data is totally flawed…………we are not talking about drain down tubs, ski houses, or a dozen people.

FWIW I ran the numbers at a DT of 70°. Incoming at 40°………..outgoing at 110°. It might be 60° in the summer.

In my own home with a direct fired Bock, I can confirm that it uses 33 gallons per month. I know this for a fact because I have the electronic fuel measuring device on one of the 2" taps. There are TWO people in this house. And, it has a timer and only maintains for eight hours per day…………..four in the morning……………four in the evening.

If the value of 10 G/month was even remotely accurate, there must be 20 G of fuel all over the basement floor. I better go down there and check!!

Roger

All you have to do is start at the date of a tank fill (topped off) after the heating season (before summer), then see how many gallons are on the next fill (before the heating season). The second fill is the gallons used over those months. We see the typical usage around 10 to 12 gallons per month for hot water outside the heating season; with an indirect tank that may be 20 gallons because it cannot thermally purge effectively; with a high mass boiler and no thermal purge, it will be higher.

hot_rod

Showers are usually a mix of hot and cold, so the shower gpm depends on the HW temperature and the blended temperature. How much cold is in the shower draw.

With washers the same if you use warm cycles which blend cold in.