Brainstorming for best hot water solution for home with 8 people

[JonnyBoy]

Redoing plumbing in the house due to mineralized joints and frozen multi-turn valves. Adding in a new water softener, but stuck on best way to provide enough hot water. One issue is basement clearance is 60”, so that knocks out most hybrid heat pump heaters. Fuel available is electric. I have considered adding a propane tank to property, but would that pay for itself in the next few years vs. electric. I currently have a 14 year old 50 gal. Electric water heater. Anyone have an idea for solutions for the best way to provide ample hot water without breaking the bank? Thanks for your help!!

 

[phishfood]

Putting in a big propane tankless might get you the amount of water you need, depending on what your max GPM demand and groundwater temperature is.

Cost upfront, you would probably be cheapest having another circuit ran and install two 5o gallon electric tanks.

 

[JonnyBoy]

Putting in a big propane tankless might get you the amount of water you need, depending on what your max GPM demand and groundwater temperature is.

Cost upfront, you would probably be cheapest having another circuit ran and install two 5o gallon electric tanks.

Would you run one tank into the other like a series? Or divide areas - 1st bath, and kitchen on one tank, laundry and 2nd bath on other tank? Would propane tankless be cost effective enough to pay for itself and tank install/ venting vs. electric bill over 2 or 3 years?

 

[phishfood]

There is quite a bit of upfront cost involved with going with a condensing indoor propane tankless. Plus tankless do require maintenance, which does add to the cost.

While I don't "know" the numbers, the energy cost would probably be less with the tankless, but it would take some time to get back the upfront and maintenance costs.

It would be easiest to try to split the two tanks up, with each serving roughly half of the total demand. In series would have the advantage of probably never running out of hot water, but the first in line would be working a lot harder than the second, and probably burn out elements faster.

 

[FishScreener]

Everything I’m reading on the newer high efficiency electric heaters say they are on a par with the tankless gas heaters energy wise. I’d stick with an electric, with a secondary hot storage tank, and a tempering valve.

 

[phishfood]

My experience with electric tankless has not been all that great. And if you add a storage tank, you loose the only efficiency gain you get from going to an electric tankless.

 

[fixitron]

I doubt that 8 people will want to take a shower at the same time, so it is a question of demand, and are we assuming that the one electric tank was not adequate for your hot water needs?
How many showers are available? How many GPM flow for the shower heads? Do you want your showers to be very hot (110+degF)? How many GPM can your water system supply? (e.g.- a well pump typically can provide 7-10 GPM). Does everyone shower or do some use a tub? Do you use a jetted tub?
These answers will help to determine how many GPM of hot water is needed and roughly how much storage vs. available recovery rate is needed. Typical electric water heaters can heat about 40 gal./hour, and some can heat up to about 50% more than that, so look at the recovery rate for the heater.
Raising the tank temperature will give more thermal storage, but will constantly lose more heat to the area around the tank.
Two tanks have more surface area than one tank of the same volume, but can have twice the recovery rate of one tank. Residential electric water heaters are no longer available in sizes above 50 gal..
Two electric tanks in series will put most of the work on the first tank, but when that element burns out, you will still have some hot water. Separate tanks for different parts of the house would lose all hot water to their section of house. Recovery rates would also differ.
Two electric tanks installed, including the added electric circuit (assuming that your service has the capacity for another water heater) would cost not that much different than installing a propane-fired tankless heater, depending on location of heater and piping needs. The tankless would be more efficient overall, when there is a large demand in a short time, but it would be sensitive to harsh water conditions, resulting in more maintenance.

 

[wood4d]

thye cheapest thing to do is put in a replacement electric water heater. He is talking about a 2 bath house.

 

[JHEARD]

I attached a copy of several variations of ways to install a tankless heater. for anyone that reads this and is curious there are several ways you can hook it up using a recirculation system or a point of use heater.

 

[edfiero]

If all 8 people shower at generally the same time, I don't see how there is any other choice other than tankless. It will provide unlimited hot water.

I have a 50 gallon propane heater today. 4 people showering (from 3 bathrooms) using new 2 GPM shower heads will drain all hot water in my house. No way would I ever try to support more than 5 people from a 50 gallon tank unless they had very different bathroom schedules.

 

[JHEARD]

If all 8 people shower at generally the same time, I don't see how there is any other choice other than tankless. It will provide unlimited hot water.

I have a 50 gallon propane heater today. 4 people showering (from 3 bathrooms) using new 2 GPM shower heads will drain all hot water in my house. No way would I ever try to support more than 5 people from a 50 gallon tank unless they had very different bathroom schedules.

I agree with edfiero... tankless heaters are more efficient by far. paired with a recirc system timed the right way it puts truth back to the "instant hot water claim" there are so many various ways you can hook that up as well. retrofit and new install. its the way to go. i own one, i service them, install them, and sell them. when done correctly they will last, outperform, and keep unlimited instant hot water running in any home. as long as the correct calculations are taken regarding flow rate required, recovery rate, and gas supply

 

[WyrTwister]

Everything I’m reading on the newer high efficiency electric heaters say they are on a par with the tankless gas heaters energy wise. I’d stick with an electric, with a secondary hot storage tank, and a tempering valve.

Were it me , I would run the 2nd circuit and pipe a 2nd electric water heated in series with the first .

Insulate both very well . Put one , or maybe both on timers .

Wyr
God bless