you got to be kidding me.....
I'll guestimate,
At 22-24% higher efficiency and the standby heat loss on a 75 gal, You'd save about $2.50-$3.00 a week.
Approximately $140.00 a year.
So Grumpy.....you have not been around for a while...
did you get back from a vacation to Europe or some place exotic?
I found another site that claims a tankless will save as much as 23 dollars per month to heat the water....
it dont seem realistic to install the tankless if all you
are going to save is a so small....
here is the article I found from the Plum biz newsletter I get
Are they really cost effective?
Last week I started prying open a can of worms concerning the cost savings of tankless versus storage type water heaters. It's been over twenty years since I had my first practical lesson in the benefits of both. With the help of the engineers at
PVI water heaters (I live less than two miles from their HQ) I wrote the specs for a municipal maintenance facility. The facility included crew showers which, if I remember correctly, would accommodate 8 mechanics at once. In theory, they would likely all be hitting the showers at the quitting time so we needed to provide enough hot water for all of them at once. To handle the task, we installed a 250 gallon tank type heater which only had about 100,000 btuh or so for a burner (I could be off a bit on the burner size). At first, I thought their engineers were just trying to spec a big tank but then I realized how much money we saved on the project by specifying this monster. For all I know, it could have been the key to winning the job.
Installation costs were shaved in several ways: The flue was considerably smaller than one which was necessary for a quicker recovery unit. This was important since the roof was about 20 feet overhead. Then, there was a considerable savings on gas piping. If we had run piping for a half million btuh burner we would have been into welded pipe sizes, instead of being able to stick with screw pipe. Let's not forget that by being well under the 200,000 btuh boiler threshold we didn't have to deal with an ASME rated tank.
The tankless market is asking us to reverse these infrastructure savings. Although there are plenty of instances where a tankless model makes good sense (I have no plans to remove them from my price book system) but, whenever the government gets involved, as in offering rebates for energy savings, then it's time to take a look at the real world that they may not have thought of. (Can you say "Daylight Savings Time?")
So, let's say that half the population of a given neighborhood suddenly decided to go tankless. Since large segments of our population share schedules ( "rush hour" doesn't just happen on the freeway). So, what happens at 6:00 a.m. on a January morning when everyone hits the showers at once?
Here's a simple example: Let's say a distribution branch is designed to handle a hundred homes equipped with 45,000 btuh storage type water heaters. If just 10% of those homes switched over to tankless, at 190,000 btuh each, demand could result in a 25% increase in peak energy demand. In other words, just as individual homes have to be upgraded to accommodate the peak demand of tankless burners, the municipal infrastructure could have to be upgraded in order to provide enough energy for peak usage. Fortunately, the high up front cost of converting to tankless will prevent hoards of consumers from adopting these units but that doesn't change the fact that several tankless heaters on a single distribution branch could cause problems.
If you don't think this could happen, perhaps I should tell you about the challenges I've seen neighborhoods experience when severely cold weather resulted in every furnace firing at once. The gas company had to bring in tanker trucks of natural gas, pumping it into the local distribution system because the infrastructure couldn't deliver enough fuel gas.
I realize this is getting a bit far fetched but these infrastructure problems would be a real headache if the population in general decided to go tankless. It won't happen, as mentioned already, but it's still evidence that tankless isn't going to solve our energy challenges.
Speaking of infrastructure and payback. Last week, I mentioned that I had found a manufacturer boasting of 50% savings. Here's the phrase from their website in case you missed it:
"[Our brand] tankless gas water heaters provide an endless supply of hot water on demand; only heating the hot water that is needed. This performance cuts water heating costs up to 50%."
I asked them to help me understand the savings claim and sure enough, they have a real live case study where they replaced a 40 gal. NG water heater with their tankless unit. They had 6 months of before/after fuel costs for each water heater (I'm not sure how they gleaned that part of the data) and sure enough, they managed to squeeze out as much as 53% savings in a couple of the months. The six month average savings ended up around 45%. This is a pretty significant savings by any measure. Very impressive. But there's a hitch: That 45% savings results in a monthly dollar savings of. . .are you ready for this. . . less than $23.
At $23 per month, what's the estimated payback (in months or years) for swapping out a 40 gal. Nat. with a tankless unit from your shop? For calculations, use a tankless unit that's just under 200,000 btuh max input with a remote T-Stat. Be sure to include re-sizing gas and flue piping as would be typical in your area when working up your prices then send me an e-mail with your bottom line number: At $23 per month, how many months would it for a conversion to pay itself back?
