Gas or Electric Tankless?

Discussion in 'Tankless Water Heater Forum' started by LilJonJon, Nov 23, 2020.

  1. LilJonJon

    LilJonJon New Member

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    Hi, new to the forum and new to tankless water heaters. I need to replace a tanked water heater and I wanted to upgrade to a tankless water heater. The details of the current setup are: I live in an area where the water is colder (in Pennsylvania), the tanked water heater is electric, but I do have a natural gas furnace. The reason I wanted to get a tankless water heater is the house is large (4 BR, 2.5 bath) but I will be living alone in it. So I definitely don't need a giant water heater to be heated all the time and I also didn't want the worry of a leak or the need to replace the water heater regularly every 10 years. Also, my understanding is that, since I don't use a lot of hot water, the savings will be even better.

    That's the background. I had a plumber come out to check it out and he immediately tried to push me towards a gas tankless water heater. He claimed that in an area like the Northeast electric tankless water heaters were not strong enough to adequately heat the water, which I don't think is right. I do know that gas can provide a higher flow rate than electric ones, but he made it sound like even if I was just running one shower the electric couldn't cut it in the winter in the Northeast. This worries me because part of the upgrade is also for future resale and I don't want to screw the next owner, either.

    The other issue is that I was hoping to just stay electric, but he said I'd need six slots on my circuit breaker, so again he said he'd recommend gas. Then he quoted me over $4000 to install the gas tankless. He wants me to go with a Bosch T9800SE160. I can't even find pricing on that unit online, so I can't tell if he's ripping me off on the cost of the water heater, which is raising my suspicions. I had been expecting to pay like $3000 for the heater and installation, so this seemed a bit high. Any suggestions?
     
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    An electric tankless can work in places like S Florida or similar where their ground temperatures never get really cold. WHere you live, the incoming water temperature in the winter could be close to freezing after a cold spell.

    I doubt you have a big enough power panel to handle that, and in reality, they don't make them big enough.

    Most gas-fired tankless systems are around 199K BTU which equals about 241A. You might have a 200A service, so you'd need to upgrade that, but don't bother, nobody makes a residential unit that large. That should tell you that the performance won't be as good as in not as much hot water.

    The general specs listed for tankless assume you input water temperature is 50-degrees. Yours probably will be significantly less. Think of a tankless like waving your hand over a candle. If you move it slow, it will get hot. Otherwise, you may not notice it at all. Water is harder to heat, so it takes a lot of heat like in a blowtorch to raise the temperature enough in the time it passes by the heat exchanger.

    Unless you're willing to find maybe a shower head that outputs 1gpm, any electric tankless you find would only give you tepid water in the winter. Even a gas-fired one might have trouble if you were filling the tub in the winter, depending on the valve you have.

    An electric WH will have less standby losses than a gas-fired one, but depending on where you live, will still cost more than a gas-fired one because of the general cost of gas versus electricity. Today's WH are required to be more efficient than those of old, primarily accomplished by more insulation.

    Most people may never do any maintenance on a tank-type WH (although a little doesn't hurt!), but if you don't do regular maintenance on a tankless, the performance will degrade. Generally, it takes at least an annual demineralization, which, if you can't do it yourself, will end up costing you probably a couple of hours labor each year. Throw that into your equation, and it may not look quite as good!

    Even a gas-fired tankless may require reworking your gas lines as 199K BTU may exceed your current gas meter and piping's capacity.
     
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  4. Bannerman

    Bannerman Well-Known Member

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    Unlike a tank type WH, a tankless WH will need to take the water from its arrival temperature, and heat it to the desired temperature almost instantainiously as it is being used. An electric tankless will typically require 100 amps just for the WH, but even with that much electrical input, the flow rate supported will be less than a gas fired tankless.

    To realistically meet the needs for a 4 BR, 2.5 bath home, a gas tankless will be required.

    Many larger capacity gas tankless units such as Navien NPE-240 will have a maximum input of 199,900 BTUs which will support from 3.6 GPM @ 110℉ temperature rise, up to 11.2 GPM @ 30℉ rise. Because a modulating burner with a 10:1 turndown ratio is utilized, the input will be constantly variable from between 19,900 BTUs (5,832 kWh) to 199,900 BTUs (58,571 kWh) to maintain the desired temperature at the flow rate needed.

    When the flow rate requirements exceed the capacity for a single gas tankless unit, multiple units maybe easily cascaded together.
     
    Last edited: Nov 23, 2020
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  5. fitter30

    fitter30 Well-Known Member

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    First have to measure the temp of your water. Then subtract that from 120* Then how many gallons per minute use think your going to use. Heres specs on that heater 4.2 gpm@75* rise. Question to ask the plumber if the gas line is large enough to run the water heater, furnace and stove at the same time. Check with your utility companies for any rebates
    https://www.google.com/url?q=https:...FjABegQIARAB&usg=AOvVaw3B0SEACnlGWbH-ZkRz5FQH
     
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  6. LilJonJon

    LilJonJon New Member

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    Thanks, everyone. It sounds like everyone is saying that gas is the way to go, so I'll do that. Does anyone know anything about that Bosch unit, like performance or cost? I was thinking about getting a Rheem 9.5 gpm from Home Depot. It's $1300. The problem is the Bosch unit only gives BTU (160,000) when I look for it online, so I can't compare the flow rate, and no site gives the price. I think it's a model that only contractors can buy? I don't know.

    Oh, also for fitter, my stove is electric, so that's not an issue. The guy came over to my house to look it over, so I assume he would know if the gas was enough to handle the furnace and water heater together.
     
  7. LilJonJon

    LilJonJon New Member

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    Oh, I guess from the spec sheet from fitter, the Bosch is a 9 gpm flow?
     
  8. Dana

    Dana In the trades

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    If you have hard water you'll be spending more time & money de-liming the tankless than anything you'd save in fuel/electricity costs. This is true whether gas or electric.

    Plain old electric tanks are cheap and low-maintenance. Current models have more than twice the insulation as stuff from 40 years ago, and very low standby losses. You'd never save enough on standby losses to rationalize an electric tankless (which is expensive to install- it may even require upgrading your electric service to run one big enough to not be a total PITA.)

    Gas fired tanks have much bigger standby losses than electric tanks, but the fuel costs are less, and have more things to go wrong with them.

    He's definitely right. You can make one low flow shower work just fine, but it takes wire fat enough to yard the F-150 out of a ditch to run it, and you'll see the power drop to the house twitch when you turn on the hot water at max flow.

    Setting up your house to please the anticipated desires of the next owner is just silly. It's your house. I doubt the type of water heater is going to be more than the tiniest factor in the resale value or ability to sell the house.

    $4K wouldn't be a gouge for any 150KBTU/hr or bigger gas tankless. There is a lot more than the cost of the unit going into it. Often the gas service needs to be upgraded, and some dedicated fat gas lines need to be run between the meter & tankless, and the venting & condensate need to be dealt with. Only rarely can it simply be tapped off the line running to the furnace (and if it can it means your furnace is LUDICROUSLY oversized for the heat loads of the house.)

    If you normally have to run a dehumidifier in the basement to keep the musty basement smell at bay, a 50 gallon heat pump water heater would cost less to run than a gas tankless, and would cover a large part of the dehumidification load. It's much simpler to install than any tankless, and since you're upgrading from a plain old electric tank there may even be local utility/state subsidies for going that route.
     
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  9. LilJonJon

    LilJonJon New Member

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    I'm confused. It sounds like you're advising me not to get a tankless water heater then? I mean, I understand that up-front costs are high and it takes a long time before you start recouping money, but I get the feeling you're saying just go with a regular tanked water heater. For example, if that's the case (and I apologize if that's not what you meant), then when would you guys recommend tankless water heaters? Like I said, I like the "on demand" nature because I'm just one guy, I sort of like the fact that it seems more efficient and therefore less wasteful, and I don't want to be pitching water heaters into landfills. But if it doesn't make sense, then of course I'll just stay tankless. BTW, I have a water softener, so the hardness of the water is less of an issue, but I get what you're saying.
     
  10. Bannerman

    Bannerman Well-Known Member

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    While a tankless may have a heating efficiency of up to 98%, efficiency is typically not the greatest benefit.
    Tankless benefits:
    • Small size. As a tankless is usually hung on a wall, this will often free-up floor space for other uses. This may not be a major concern in a large home with a basement and few occupants.
    • Never ending hot water. Since water is heated as it is consumed, hot water can continue to flow 24/7 without worry of a tank capacity limit.
    A hybrid WH that Dana mentions, will utilize heat from the environment to heat water, similar to how an air conditioner transfers the heat from within the home to the exterior or how a refrigerator moves heat from inside the box to the space outside of the refrigerator (warm coils behind or below the fridge).

    As it is more efficient to transfer heat than to create it, a hybrid WH will often be more than 100% efficient (more heat transferred than the electricity consumed to move it) but since the heat is usually transferred from the basement space, you will likely be heating that space with a furnace regardless. As you may want to air condition or dehumidify the basement space during the summer, the cool dry air exiting a hybrid may be welcome.
     
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  11. LilJonJon

    LilJonJon New Member

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    The plumber had suggested a hybrid tanked water heater, too. Tbh, I haven't looked into that at all, but I told him that I sort of didn't want a tank in my home. To me, that's the biggest benefit of a tankless unit, in addition to the on-demand function, of course. Is that something I should just ignore? Like do I sound silly even considering a tankless water heater for that reason?

    Add: I just looked briefly into this and the couple of sources mentioned that hybrid water heaters use the heat of the ambient air, so I don't see how that would work in a cold-weather area like Pennsylvania. Maybe in the summer, but the winters are pretty cold. Also, my water heater is in the basement, so even the summer the temperature is like in the 60s at best. Also, it seems like hybrids are also fairly expensive to install. So I think for me it still falls to choose between a traditional electric tanked water heater or a natural gas tankless water heater.
     
    Last edited: Nov 23, 2020
  12. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    A tankless system depends on its heat exchanger being clean with no mineral buildup. Because of the significant heat, that tends to drive any minerals out of your water that get deposited on the heat exchanger. WOrst case, it literally blocks it, but prior to that, it adds a layer of insulation until it cannot provide the desired amount of heat. You need to delime them on a regular basis. First, it's easiest if it's installed with the proper bypass/isolation valves. Then, you need a pump and an acid to pump through the heat exchanger to dissolve those mineral deposits. Most tankless systems call for doing this annually to maintain proper operation. If you have really hard water, you might need to do that more often. Even softened water is not immune, but slows the rate at which deposits accumulate. Softening does not remove all of the minerals, just lessens the amounts.

    The way tankless systems are advertised, can be confusing. The only way you'll get those high numbers like 9+ gpm is if your in like south Florida where the incoming water may be 70-degrees or higher. Your water will likely be in the 30-degree range in late winter, so that means the water needs to sit in the heat exchanger longer (by a lot!), and the only way that happens is if your flow goes way down or you can accept the outlet water temperature being much lower. Say 75-35, that's 40-degrees less. If it was trying for 120 at maximum volume, you might only get 80-degree water out. Note, not all shower valves will let you flow full hot, so your actual shower temp could be much lower.

    If a tank is sized properly for you intended use, in between those uses, it has the chance to recover, so does not need anywhere near the burner or heating element size. The only time this is normally a problem is if you have a situation where you have a constant, high demand and the tank cannot recover.

    From an energy viewpoint, a hybrid wh tank can be a good choice. Depending on your electrical costs, a plain electric one is probably the most efficient as nearly all of the electricity goes into heating the water. Some of the gas-fired units are in the high 90% range. Their standby losses will be higher since there's a flue going up the middle of it that cannot be insulated as well as an electric.

    Your infrastructure in the home needs to be robust to handle a new tankless gas unit. It might be even more costly to upgrade your electrical service to handle an electric tankless. A hybrid electric unit is usually available to install in most panels without upgrades, and doesn't need a flue.

    There are ways to make a tankless system work for nearly any required volume, but that often involves ganging more than one unit which can put some serious demands on the gas supply or the electrical panel that may not be easy as the utility might have to install a new transformer and they don't like the intermittent significant spikes in demand, and you'll usually pay extra for it. The equivalent electric unit to a 199K BTU gas unit would draw 58Kw at peak, and 232A. Something that drew maybe 100A would have less than half the capacity of the gas unit.

    You can figure things out for yourself. 1-gallon of water is about 8.3#. To raise one pound of water one degree F, takes one BTU. A typical showerhead draws a bit over 2gpm of hot water, but not more than 2.5g. For most people, a comfortable shower is maybe 104-5 degrees (some like it hotter, some cooler). Say it is coming in at 35-degrees in the winter, and you want the hot 120 so you can mix it with some cold, you need to raise it 85-degrees. One BTU=just under 3W. The rating of BTU is per hour so you need to multiply the gpm * 60 to get it per hour. It's a LOT of energy.
     
  13. TEch99

    TEch99 New Member

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    This should be pinned to the top of the Tankless forums. Electric tanks have been nothing but reliable, near maintenance free ( Anod rod and elements maybe every 5 years), great on energy usage, cheap installation cost and any plumber can work on them, no venting pipes, exhaust or gas needed. Seems on average a sensor will go bad on a tankless every 3 years if lucky, with an average repair cost of $400 which is the price of an entire electric tank water heater or the heat exchanger leaks and other issues they come with. This is aside from yearly maintenance or the initial inflated installation cost on these new tankless.
     
  14. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    For the average American, the only place an electric, instant hot water device makes some sense is for a single point of use like maybe in an isolated bathroom for the sink. Otherwise, the spike in power, the wiring, and the limited volume just becomes a major pain. Yes, we're spoiled. Yes, gas tankless units work for some people, and could for everyone, but may take multiple units ganged together to handle multiple users as a single one probably can't unless you're in the tropics and your water is already warm. Those that live in the northern part of the US where it can get and stay below zero for a few days (or longer!) on occasion, still want a hot shower when we want it. That may not happen with a tankless unit unless it was sized and designed for those conditions.

    Eventually, we may start to see demand pricing where your base service cost depends on your peak use (not average). Tankless units, whether gas or electric cause a HUGE spike in demand when operating. That can put a huge stress on the whole network. Think what that would mean on a cold day in the morning, when every furnace is trying to warm the house up after a setback overnight, and everyone tries to take a shower with their tankless units! The load could immediately increase by maybe a factor of 10 or more...that's problematic. A tank is a much smaller load, and as a result, takes much longer to recover. But, may not call for any energy off and on like a tankless unit.

    The town next to me does that for water. One complex had fire sprinklers installed. Normal homes. But, because they required large water pipes, their base water costs are huge in comparison to a home with say a 3/4" or 1" supply line. That happens with electricity and gas in some places, but I think it will become more common in the future. FWIW, read recently that new construction in San Francisco after 2025 cannot have natural gas for anything, including heat, hot water, etc. Burning fossil fuels is going to become less tolerable for society and the health of the world. If you're in the market for new construction, you may be forced into all electric and may want to consider some solar cells or hydro-thermal sources of energy. I don't see wind power becoming much of a residential thing, but solar and battery storage will be the coming thing.
     
  15. LilJonJon

    LilJonJon New Member

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    Sorry, but this makes me call into question all of your advice because, unfortunately, you seem to be injecting your politics into the discussion when I didn't ask for it. Like if you're telling me not to get a tankless water heater because "fossil fuels are bad for the planet" and then are pushing me to use some solar power-generated system, then I'll politely not care. I was looking for advice and I got a lot of biased commentary. For example, I noticed that in every thread on tankless water heaters, Dana immediately pushes people towards a hybrid water heater, just like in this thread. Literally anyone who asks any question about a tankless water heater immediately is recommended to get a hybrid water heater. That's not helpful at all. Sorry.
     
  16. TEch99

    TEch99 New Member

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    That's unfortunate that that's all you gathered from his post.
     
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  17. Dana

    Dana In the trades

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    The financial "payback" of a tankless= never (maybe even 2x never for a single person household. :) )

    Tankless solutions can make sense when space is at a premium, cases where buying back another 5 square feet of floor area is considered worth the upcharge.

    A heat pump water heater is less wasteful than a tankless. The standby losses get recovered using less than 1/4 the amount of electricity that it would have taken to re-heat the water with a resistance element to maintain temperature (the way a plain old tank does), and on average heating the water actually used takes only about 1/3 amount of electricity of an electric tank, with 2/3 of that heat drawn from the room. In a humid basement the larger fraction of that heat taken from the room is the "heat of vaporization" of the water condensed from the room air. During a PA winter when the indoor & outdoor air is drier it takes that heat from the heating system, lowering the room temperature in the process. But the lower room temperature also reduces the heat lost through the walls to the cold outdoors- it's not a simple model. During the summer it takes some of the load off the air conditioning or dehumidifier (assuming you use a dehumidifier to control basement mold.)

    But if local electricity prices are substantially lower than the national the financial payback might be "never" with a heat pump vs. a plain old electric tank too.

    Explain more why you don't want a tank(?).

    The leak risk is a non-starter- tankless units can (& do) leak too. Tank lifespan for glass lined tanks is largely a function of the number of deep thermal cycles (that induce mechanical stresses) and total volume of water that moves through the tank. With a water softener it will go longer than with hard water (which eventually can eventually fill the tank with scale.) An electric tank in a 5 person household taking daily showers might only last the 10 year warranty period, but for a single person household 25+ years is likely.

    So yes, you should probably recalibrate the perceived higher risk of a tank and ignore it. The actual risk is quite small. There is a higher fire risk to gas appliances vs electric, and some people perceive that risk to be higher than it actually is as well. In reality most people have more serious risk factors to deal with than floods from failing tanks or fires from gas leaks, both of which can be mitigated.

    That isn't political- the arguments for heat pumps vs. tankless are both functional & financial. And the perceived benefits of a tankless (for those who haven't experienced tankless water heaters) are usually bigger than reality.

    Any carbon emissions issues are way in the background (even for those who care deeply about it), especially for a water heater serving a single person household. If one is seriously concerned about the carbon issues there are almost always more effective places to apply that money in an existing house than the water heater. A very few locations in the US have begun banning the use of fossil fueled mechanicals in new construction, but they won't be digging up the gas mains any time soon (probably not within the lifecycle of a gas water heater anyway.)

    For MOST people a heat pump water heater is simply a better solution than a tankless. It provides much higher flow when needed (filling tubs, etc), and it costs less to operate, install & maintain than a tankless. As it happens it's also more efficient and has a lower carbon footprint than a tankless. I bring it up a frequently because it's not even been on the radar as a solution for many people. The down side to heat pump water heaters is the slow recovery time and lower first-hour gallons than a tankless. But those are only an issue for 4+ person households (who may need more than 50 gallons of buffering capacity), and a complete NON-issue for a single person household (unless you have a huge spa tub to fill, which would also be an argument against tankless solutions.)

    FWIW: I neither hate nor love tankless water heaters- but I do understand them pretty well. I lived for well over a decade with a gas fired tankless water heater (in cold-water MA) and it was fine despite a few quirks. The biggest drawbacks for us were perceptibly slower fill times for tubs, poor (but tolerable) temperature control in a shower when other appliances (notably the clothes washer) was in use making intermittent draws during a shower, poor temperature control (including summertime flame-outs) at very low-flow at sinks, and the inability to deliver hot water to intermittent short draws from the dish washer. It had some maintenance issues- I replaced the flame detector a couple of times, had to clean up & un-stick a temperature control valve once, but it was retired still working. Despite the quirks it was fine overall, and might have kept it if I needed the space. Newer/better gas tankless designs have mitigated some inherent quirks, but not completely.

    During major revisions of the heating system the tankless was replaced by a 48 gallon "indirect" water heater, (supplemented by a ~50% efficiency drainwater heat recovery heat exchanger returning heat going down the drain back into pre-heating the incoming potable stream.) Strangely enough, I'm using a (different model) tankless water heater as the hydronic boiler, heating only heating system water in the tankless directly, heating the potable water through the indirect's heat exchanger. There are some quirks to using a tankless water heater as a heating system boiler too, but it's been pretty reliable for over a decade now, the only maintenance issue being cleaning out the tiny screen filter at the inlet once every year or two. (Had there been inexpensive stainless fire-tube heat exchanger boilers with bigger turn-down ratios on the market then I probably would have used one of those instead.) I'm OK with this tankless application too.
     
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  18. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    On demand, instant tankless systems work fine if your intended use fits the situation. They cost more to install, maintain, and those two things often mean that you can never recover costs, if that's your main goal. If sized properly for the demand, they can work. They have their quirks, like they may not turn on at low water flow say at a sink when you just want warm to wash your hands. When the incoming water is quite cold, because they have a limited temperature rise, it may not suffice for your needs. For the vast majority of people, they aren't the best solution. FOr some people, local rules may make them unavailable, and that's all I was saying (SF is one, starting in 2025).

    A tank needs to be sized properly for your demands, too, or you'll run out of hot water. The main argument for a tank is they run out and for some, they take up too much room. Any plumbing device can leak.

    You can filter out honest suggestions...it's your prerogative.
     
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  19. LilJonJon

    LilJonJon New Member

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    Thank you, Dana, for the clarification. It was much more helpful and explanatory. jada, sorry if I took it out on you. I'll just give you guys an update before I leave the forum. Hopefully, this helps out anyone else who is trying to decide on a tankless water heater in the future. I decided that the cost for a tankless water heater and the concerns for not being able to heat a high enough flow rate to a high enough temperature in winter were too great a risk. In addition, the hassle of retrofitting my home was, as you guys discussed, a factor. I therefore looked at just a traditional electric water heater versus an electric hybrid water heater. I looked at a few video reviews online and the major issues for people in the north (unfortunately, it seems like people in the south have it great) were the noise and the cooling.

    There was actually a video from a guy in PA who had installed a hybrid water heater in his basement, which is where mine would go, and he said this dropped his basement temperature over 6 degrees, which really worried him for the winter. His solution was (not great) to consider just going with electric heating during the winter months, but he was undecided at this point. That would obviously diminish the cost savings, which he did understand and made clear. Alternatively, some people have pointed out that the cost of heating a cold basement back up again, while technically inefficient, is still less costly than just using a regular electric water heater. Another option some people online have considered was to create a ducting system to pump cold air outside the home in the winter. However, from what I researched, this is actually less efficient than just heating back up the air with your home heating system.

    The noise is another issue. My plumber only supplies AO Smith hybrid heaters. I guess you get whatever his company decides to buy. He told me that he would install anything I wanted, but if I bought it and he needed any other supplies he would make me buy those and bill me for holding up the installation. That's a pretty d*ck move, so I don't know if I will continue to use his company. (I just bought the house and it's the company the previous owners used, so I decided to just go with them.) Anyways, the AO Smith heater was reviewed by some guy online who said it was so loud that his wife couldn't sleep in the bedroom above the heater and they had to return it. I did ask the plumber if there had been any issues with homes he had put the water heater into and he said no, for what that's worth.

    So I decided for the cost savings and the usage of less electricity I would roll the dice on the AO Smith hybrid water heater. I hope I don't live to regret this if my basement is freezing or noisy. Thanks again to everyone.
     
  20. Dana

    Dana In the trades

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    The cooling is simply a function of how much hot water you use.

    The noise problem has been improved a HUGE amount since the early days. Current units are 3rd or 4th generation, and the vendors have been paying attention. There are even refrigerators louder than some of the current offerings. Anything under 55dbA on a basement installed water heater would be barely heard (if at all) on the first floor. Most vendors publish their noise levels these days.

    He either has a 10 person household or VERY tiny basement. I'll bet the real cause of the colder temps was an un-insulated air leaky basement and cooler outdoor weather than recent years. A more typical number would be 1.5F average temperature drop in a 1000' basement for a family of 4. For just you as the sole hot water user, forget about it.

    That's right. Unless the outdoor air is still warmer than the output of the heat pump water heater's air (~40F) depressurizing the house by pumping the air outdoors is less efficient.
     
  21. 2stupid2fixit

    2stupid2fixit Member

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    Location:
    Penn Forest Township, Pennsylvania
    I tried to pinpoint where in PA you were from your posts but I either missed it or you didnt mention it. PA has probably (im no expert) one of the more diverse climates that could affect the efficiency of a tankless water heater. Remember that PA goes from Phantom Fireworks on the PA OH border all the way to the burlington bristol bridge on the other side. Up and down we have NY and Erie and on the bottom we even have crazy stuff like WV MD and DE, but the point is WHERE in PA makes a huge difference in selecting a tank or tankless or nat gas/propane vs electric tankless or point of use tankless vs whole house tankless. You may have covered this in the thread but when I lived in southeastern pa and the gas service was cheap or at least stable and reasonable, the municipal water came in at fluctuating temps, sometimes with great difference because it came out of the delaware river and the river changed temps. Tankless utility supplied gas fired was a good idea there. When I moved full time to the top of a mountain in Carbon County, the water temp changes but not so drastically different then witch tit cold. Winter time it comes out of the ground (well water) really cold and in the summer time it comes out of the ground almost really cold. Tankless was a bad idea because as mentioned, for one to achieve the rate of rise in degree temp change to have shower useful or washing machine useful hot water temp, that would make sense economically only if the kilowatt hours and the wire to deliver them were free. The same solution on propane, would have used a big delivery of propane and huge btu output unit and propane aint cheap since someone has to drive it to you from a truck. Electric tank water heater made more sense since the water could sit in the tank for a while unused (unless a daughter hit the shower) and have the help of being in the house for a bit as the electric was heating it up too. I would love to have a tankless propane but every vendor that I have asked about doing it says I should not. If you take out all the calculus, the folks that did end up with tankless propane water heaters around me either are not happy with how they perform and the ones that have the huge consumption units must get money from a photocopier because the dont care their tankless heater burns as much fuel as it does, when a standing tank heater would be way more efficient.
     
    Last edited: Dec 7, 2020
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