Value of 96% HE 75gal water heater vs. 80% standard 75gal water heater

6 years ago

Building a new house. Thought about a tankless but seems like they aren't very good. We can get the 80% standard 75 gal water heater or upgrade to the 96% High Efficiency 75 gallon one. Upgrade costs about $2800... is it worth it? Any better experience as a water user or should I just hope to shave $10 off my bill every month and be better for the environment?

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David Cary

6 years ago

last modified: 6 years ago

Those numbers are definitely gas.

$2800 seems like a lot. Longevity is of course variable and paying more probably gets you greater longevity. I haven't looked in a while but Marathon sold ones that significantly outlasted average ones.

The first question is what is your fuel? NG is cheap and Propane is not (well it is relatively cheap now but more variable).

Next is - not sure where you heard that tankless is not good. I have my issues with tankless but they should be considered. I have one in a new rental townhome and the water takes a long time to get hot. That is an issue but doesn't have to be. Some of that is plumbing but some is the nature of tankless. But in general tankless is the goto for many. It is a lot cheaper than $2800 and gives you 96% typically.

Third question is why not use electricity? Heat pump hot water heater makes sense in a lot of environments. But you need to have the room and sound isolation.

Lastly, there is some value still for solar hot water if you are concerned about being a good steward for the environment. Best if you don't have room for heat pump hot water. It also will outlast a heat pump. We paid about $7k but got $5k in incentives so it was a minimal cost to us for a good 80 gal tank with install.

When considering the options, I always think it is good to remember that gas can not be created in a renewable fashion but electricity can. Also many electric utilities offer rebates for highly efficient electric devices. Many would be surprised but there is a growing return to electric resistance type hot water heaters for this reason. Particularly POU devices that eliminate the wait (and waste) of distributing hot water.

I am still trying to figure out Duke Energy's incentives but I think we may be going back to solar if the incentives are still there.

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Comments (11)

kudzu9
6 years ago
One way to view this is to look at the EnergyGuide labels on the two water heaters, which give the annual estimated operating costs. Subtract the smaller number on the more efficient one from the larger number on the less efficient one to determine annual savings. Now the typical water heater might last 15 years, maybe less; if you divide $2800 by this number, you get an additional cost of about $186 per year by going with the more efficient one. If the annual savings you get by comparing the EnergyGuide numbers is less than this, then it doesn't make sense economically. As for being socially responsible and environmentally aware, you'll have to make up your own mind...
mushcreek
6 years ago
If they are both straight electric heating, there won't be much difference, and $2800 is a huge rip-off. That will get you into a heat-pump water heater, which is a lot more efficient. The installation of a heat pump water heater is more involved, as they are noisy and produce cold air. You can't just stick one in a closet. When we built, we went with a generic electric heater, as the heat pump models were still rather new on the market, and seemed prone to lots of failures. I'm not sure where the industry is at now.
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I've lived with a tankless for 12 years and would never go back. You get an endless supply of hot water. Endless. For folks with ginormous bathtubs, that's a big bonus. I have a smaller unit, as it's just 2 of us, and because the temperature of the groundwater fluctuates, we have to set the flow rate to a bit less in the winter so as to get more heat from it. But, that reduced flow rate is still more than enough to satisfy a 2.5 GPM showerhead, especially if you make the mental adjustment necessary to understand that you're heating the water up to just above what a comfortable shower would be and barely using any cold water to temper it. That's the biggest mistake those folks new to tankless make. They want the water to be the same temperature as a tanked heater, when it's totally not necessary. Traditional water heaters are set at a much higher temperature so that users will temper the hot water with cold water and thus the tanked supply will last longer under use. For new construction, it'd be an no brainer for me. I'd choose tankless all the way. It is a LOT more difficult to retrofit, because the flue size is larger, and needs to be stainless. The gas piping also has to be sized correctly, and that usually involves a dedicated 3/4" line. That's why the folks that are not in love with tankless will raise objections about cost. In a retrofit situation, where someone has to pay for the labor and materials rather than DIY, it's probably going to take a long time to pay for the cost difference. In new construction, where nothing yet exists that has to be modified, I'd be surprised if the additional materials and labor costs approached $500 even. And, many many municipalities are offering tax credits for the installation of tankless, so it may not even cost any additional on the front end. Another big bonus to the tankless is the size of the unit. Ours is about the size of a suitcase hung on a wall. Compared to a 75 gallon water heater, that's a lot of room saved in our laundry room. If you live in a temperate climate, they can even be sited outdoors and still be fairly non obtrusive. The energy savings are real. Although we're a family of just 2, we saved approximately $35 a month over the old water heater. Sometimes, in the summer, our gas bill is only the minimum charge necessary from the utility. That's $9. And, we use a LOT more hot water in the summer than we do the winter because of outdoor activities making us hot and sweaty. I love being able to jump into the shower and not have to worry about leaving enough hot water for hubby and the 3 loads of laundry that I need to do.
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Funny to be accused of evangelism by poster that incited an "Amen", a few posts up :) Always appreciate feedback and constantly working on preachiness of writing style. I think including links or reading opines without sourcing helps others decide on misleading comments. It looks like Stiebel updated their Accelera HPWH to include an electronic control screen since we bought one a couple years ago for parents house. After an updated check on reviews I still feel safer with Accelera but it's hard without knowing volume of units sold. Surely Rheem has sold more HPWH than Stiebel at this point, despite Accelera being around longer. Reliability is a compelling reason to go with Rheem Marathon an electric resistance tank. Best warranty and most well-reviewed water heater available. Tank size plays a role here too. Bigger tank means better hot water performance, with minor hit in efficiency. The bigger the tank, the better for grid storage and demand control. Demand control has been around a long time with the most basic strategy using a timer and time-of-use billing options through utility. Studies will continue forever on more advanced grid-smart water heating technology but at this point, it's a time-tested technique with this smart water heater article quoting up to one million in use already with potential savings for homeowners and grid. Another article from same site points to irony of battle between grid storage potential of simple electric resistance tanks and the efficiency of heat pump water heaters. In that first article the Hidden Battery link seemed misdirected but it was put out by the NRDC pointing to potential of electric tanks to reduce the need of new power plants and grid storage for renewables. Large, reliable electric resistance tanks are becoming more of an asset while gas is becoming more of a liability. I think most of this forum's posts could be described as meaningless or feel-good-only but definitely not water heating. It has large environmental and social consequences. It's one of the only home purchases capable of beating the stock market for returns on investment. I think the ROI currently lies with HPWH but the second best choice could easily be a good ole electric tank. If an electric utility offers good incentives, electric tanks like the Marathon, could beat tankless gas or HPWH in total lifetime costs including repairs and replacement. A home equipped with PV panels and Marathon tank could also be in the running as best long-term water heating investment.
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User
6 years ago
They are both 6 yr. tanks. Take the 80 percenter and bank the savings.
schreibdave
6 years ago
The high efficiency water heater likely is plumbed to the outside to draw in air for combustion. The 80% one likely burns interior air. Burning interior air prevents you from being able to have a really air tight home. If you care about that.
kudzu9
6 years ago
In my experience, even most new houses aren't so tight that they don't allow air to be drawn in. If the OP is trying to make the house super-tight, and is concerned about this issue, a simple solution is to have the water heater in a utility closet accessed from the outside which draws outside air. That's what I have.
Tracey Grant
3 years ago
last modified: 3 years ago
The primary disadvantage of on-demand or instant hot water heaters is the upfront cost. The smaller units that you often see won't produce enough hot water to serve most households. Tankless water heaters can provide an unending stream of hot water almost instantly, they will function for twice as long as a standard, high-quality water heater, tankless water heaters are 22% more efficient than standard models, and because they are more efficient, tankless heaters qualify for federal tax credits, which help offset the steep installation cost. At https://www.liferejoice.com/best-tankless-water-heaters/ you can find a review about the best tankless water heaters available on the market in 2020, which will ease your choice significantly.
BT
3 years ago
Please do not bring back 2 year old threads... I am sure whoever was the original poster - she completed her house long ago.
schreibdave
3 years ago
What's wrong with commenting on an old thread?
David Cary
3 years ago
It brings the thread back up when some have already seen it. Nothing is really new but it takes up space. You have to scroll down to get to the new activity. So overall, it adds noise and time for little new activity. And the person who the thread was helping is certainly gone.
Jake The Wonderdog
3 years ago
The above is off-topic spam.

Value of 96% HE 75gal water heater vs. 80% standard 75gal water heater

David Cary

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