VIDEO TRANSCRIPTION
Tankless Hot Water Heater Overview
Tankless water heaters are a relatively new way to provide domestic hot water to a home. Sometimes called on-demand or continuous water heaters, tankless units are designed hot water when and only when it is called for. According to the Propane Education and Research Council, tankless water heaters, especially those fueled by propane, save energy and water and emit fewer greenhouse gases than conventional storage type electric water heaters.
Of course, savings vary by household use, local utility rates and other factors. Still, many contractors aren’t sure how tankless water heaters work and might be a little sceptical about their performance claims. To answer those questions, let’s take a look at how a tankless heater compares to a storage water heater by looking at the guts of both products.
Let’s look at conventional water heaters first. Residential storage type water heaters use an insulated tank, usually about 40 gallons in capacity.
The water in the tank is kept heated at all times for delivery, so the unit is always on and using energy, albeit at a very slow rate, to maintain water temperature within about 10 degrees of the unit’s thermostat setting. The main water supply enters from the top of the tank, a dip tube extends that line to the lower section of the tank.
When hot water is called for inside the house, the water in the tank begins to flow through the home’s plumbing system, through a second pipe at the top of the tank.
A separate chamber below the main tank contains the unit’s heating element, which is controlled by a thermostat or for natural gas and propane units, a burner control. As the hot water in the tank is exhausted, the burner below ignites to heat incoming freshwater.
Little or no hot water is available during this recovery time. Storage water heaters provide a relatively low installed cost, a variety of sizes to serve large and small homes, and respectable flow rates to deliver domestic hot water.
Because of its size, however, the storage water heater is usually located in a home’s utility closet or garage, not always a centralised location within the home’s floor plan. As a result, delivering hot water through the home can take a few minutes, a condition called lag time that all water heaters experience to some degree. This lag time, though, wastes several gallons of unused water and can be inconvenient for the owners.
Now, let’s take a look at a tankless water heater.
These units use a compact metal cabinet instead of a tank. Because there’s no pre-heated or standby water to manage, there’s no need to insulate the cabinet or maintain a level of heat or heating energy. So, instead of being always on, a propane tankless heater only uses energy when there is a demand for hot water.
Otherwise, it’s effectively off. That difference accounts for the bulk of energy savings and reduced emissions afforded by tankless water heaters. When hot water is called for by an appliance or a faucet, cold supply water flows into and through the unit. A sensor detects the flow, triggering a computer generated signal to send propane to the heating element and bring combustion air into the inducer motor.
This exterior unit draws combustion air from the intake at the top and exhausts it from the louvred vent near the bottom. Units installed inside require a sealed combustion direct vent pipe that both brings in and exhausts combustion air safely from and to the outside. The flow of propane triggers the burners to ignite, warming the heat exchanger. These pipes curl around and through the exchanger, heating the water as it flows.
The heated water is then delivered through the home’s plumbing system to the appliance or faucet being used. This process enables a tankless water heater to deliver an almost unlimited amount of hot water, even if more than one hot water using appliance or fixture is on at a time. And once the tap is turned off, so does the unit and its energy demand and related energy cost. The space-efficient design of tankless heaters enables them to be placed strategically throughout the house and even outside to greatly reduce lag time and the amount of water wasted in that process.
Before we conclude this insider’s view into domestic water heating, here are a few quick tips for choosing and installing a propane fueled tankless water heater:
- Size the unit for the home’s specific hot water needs.
- Provide adequate capacity for the water supply and delivery network.
- Oversizing a unit actually works against the advantages of a tankless water heater.
- If the home has a lot of needs consider multiple units and dedicated plumbing to ensure their performance.
- Installation is relatively simple, similar to a storage heater and should be performed by a professional plumbing contractor.
- The water supply line typically connects to the bottom of the tank as does the delivery or outgoing line.
- On this exterior unit, the dedicated line for propane also connects at the bottom of the cabinet.
- The unit also requires electricity and control wiring to operate its electronic components.
- For any type of water heater, it also is a good idea to treat any water source that’s mineral rich or a poor quality. Doing so extends the life and performance of the unit.
Compare Tankless Water Heaters
Many hot water manufacturers make tankless water heaters. In deciding who makes the best tankless water system, it ultimately depends on what the end user is looking for. Below are a couple of tankless water heater reviews for two recommended tankless hot water system suppliers.Rinnai Tankless Hot Water System
Their tankless water heater copper heat exchanger is commercial grade and includes a 12-year limited warranty. Making it stand alone as an innovative technology is the Rinnai concentric venting system. Rinnai has won a number of awards for their energy efficient tankless hot water systems such as the “Super Nova Star Award.” Also, they were selected as the “Best Tankless Whole-House Water Heater” by Bestcovery.com. With over 40 years experience and 30 million sold in the world, Rinnai makes some of the best tankless water heaters for the Australian market. Rinnai continue to strive to keep the purchase cost as low as possible.Rheem Tankless Hot Water System
Their hot water heater features are made to be very user friendly. With a large digital display, the water temperature can easily be changed, set and monitored. If ever there are maintenance issues they have a self diagnostic system that displays different codes. Their tankless hot water system designs are a successful attempt to make their water heaters more convenient and less expensive for their customers. Incredibly some tankless models can even be installed under the laundry, bathroom or kitchen sink. Rheem’ tankless hot water systems were recently featured as one of the top 100 green products in the “Building Products Top 100.”Why You Should Consider Installing a Tankless Water Heater
Tankless water heaters are becoming more and more popular, ask any Sydney tankless water heater installation plumber and they will tell you the same; and there’s a good reason why too! Some people consider that a tankless water hot heater is only good for use in warmer environments and climates, but that’s not true. Tankless water heater manufacturers have designed whole house models that can be used in even the most frigid of environments and climates. After you have decided on the system best suited to your needs you can rely on Anytime Hot Water for a professional tankless hot water heater installation.How Installing Tankless Water Heater Will Change your Daily Routine
The biggest advantage to a tankless hot water heater is that there is no standby heat loss. On a normal tank hot water system, the water continually struggles to maintain a constant temperature through a thermostat control. The problem is even when you aren’t using any hot water, the hot water system is on and using gas or electricity. This can add up on your utility bill, especially when we are considering the larger models usually found in larger home or commercial premises.The Biggest Advantage of Having a Tankless Hot Water System
You will never have to wait for hot water again. If you have multiple family members who all line up for a shower or bath before you do, the hot water will never run out. An installed tankless hot water system ensures the hot water is immediately served, this means you will never have to wait for it to heat back up, like a tank water heater. Ask us more about how tankless water heaters work as well as prices on a tankless water heater installation. we are here to helpWhich Is The Best Tankless Water Heater System To Buy?
VIDEO TRANSCRIPT
On today’s episode we’re going to take a deep dive into tankless water heaters.
There’s a bunch of different options and models out there but we’re going to be focusing specifically on gas, natural gas or propane.
Pros and cons, why you might choose one versus another and I’m going to at the end of the video give you some recommendations if you’re building new or if you’re remodel retrofit which model I think might be the right one for you.
So first off, today’s video, we’re not sponsored by anybody. I’m really agnostic about brand today, but I want to give you an overview so you’re a smart consumer. There’s really two types of tankless water heaters. There’s non-condensing and condensing. You notice these two smaller units right here, these are traditional models. They’re non-condensing.
These typically across all manufacturers are roughly 0.8 EF rating. The condensing models are about 10% more efficient with a 0.9 EF rating. What does that translate to into dollars? That means for every dollar of gas I put into this unit, 80 cents on these non-condensing units is going to be transferred into hot water. Twenty percent is going to be lost to the atmosphere. On these condensing models, 0.9 rating, that means 90% of that dollar is going to be converted into hot water. 10% is going to be lost to inefficiency.
So these are very efficient models and again we’ve got no stand-by loss here so they’re only going to heat up when a fixture is opened and there’s flow through the unit which means it’s calling for hot water. Now, if you compare these two EF ratings with traditional tanks, typically a traditional tank, a good one, is somewhere around 0.55 to 0.7.
So these are certainly 15-20% more efficient across the board than a standard tank type unit but the big reason to choose one of these is the luxury of endless hot water. There can be some energy savings but it’s really something that I would say you want to downplay with your client because it’s limitless hot water is the reason to buy one of these.
Okay, so why would you choose this non-condensing model over it’s more efficient condensing cousin over here? Several reasons. Because these are non-condensing there’s less to go wrong with them. There’s less parts involved, there’s less technology. This is a very proven, very old technology, it’s really mature.
There are also less costs initially to install than these units and the other thing I like about these models is we don’t have to worry about disposing of condensate. These condensing models by condensation we’re talking about these types right here are actually going to gather water and as it gathers water and condenses that water that’s how it rings out the extra efficiency. But it also means that these have to have a place that they can drain to.
Now, either one of these can be mounted both on the outside like this unit right here, or the inside, like this one that has a flue attached to it.
I like the outside mount units, if you’re in the south. If you’re in a place where it doesn’t freeze a whole lot during the course of the year, this is a great option right here. There’s no venting on these, you just mount it on the outside of the house, and it blows the exhaust gasses out right here.
Now on the non-condensing version like this one, one problem with these though is they require stainless steel vent pipe. Because the condensation that might occur in the pipe is very acidic and because the flue gasses are pretty hot, these have about 300 degree flue gasses, you’ve got to use the more expensive piping. So that’s a little bit of a downside of the non-condensing or mid-efficiency models. Now as I mentioned, I’m pretty brand agnostic on this video. Really, these things that I’m talking about today are across models.
Now let’s step up to the higher efficiency condensing model. The big beauty of these is now we can vent with PVC pipes. We’re going to plug in a standard and inexpensive PVC here, this is the air intake, and this is the air exhaust and the gasses that are coming out of this are only 100 degrees and that’s why you can exhaust with standard PVC.
Now if you’re building new, I like this particular model – more efficient and the PVC venting is a big deal for me. The reason why I like that PVC venting is I can seal around those really well from an air sealing standpoint. Meaning this could be in a laundry room, in a basement and I don’t have to have an open flue to the outside. I just have a PVC pipe, I can spray foam or caul around that and seal it really well so it won’t have any air leakage around that pipe. Whereas these that have the stainless steel pipe, I can’t do that.
I’ve got to be a little bit more cautious about air sitting around these and it’s much harder to do with that stainless steel flue. The other thing I like about these too of course is the energy savings. Now, it’s going to take you some time to catch up on energy savings, you’re not going to choose that energy savings as the main reason, but this is the most efficient model you can find in the category today at somewhere around 90% efficient or even better.
Next lets talk about capacity. Now, all these different flavors here come in different sizes meaning gas inputs.
The biggest size you can have available is 199,000 BTU. That’s a cutoff on 200,000 because above that you need a special plumbing license called a boilers license to install those. So typically these residential models you’re not going to find any bigger than 199. You want to be cautious about your input temperature and you’re overall capacity, meaning where I am in the south, I have fairly warm water going into my tankless.
Usually around 50-60 degrees is my input temperature. Whereas if you’re building in Connecticut or like my friends in Boston you could have 35-40 degree water going into this, so it’s got a lot more work to get it up to that 120 degrees which is your final output. Which means that the same unit in Texas is going to produce actually a greater flow of hot water than it would in Boston in the winter time so you’ve got to be cautious about capacity. I think you’re always better off upgrading to a slightly bigger size than you think you might need just to make sure you’ve got sure you’ve got plenty of capacity.
Alright, to close this out, let me give you some recommendations on which models I’d recommend if you’e building new or if you’re remodeling. If you’re building new, I think that this model is the way to go. This is the condensing models and the biggest reason I say that is because of this right here- that PVC venting, I really like that. I can get a good air seal on that and I can make sure that I don’t have air leaking in that flue. It’s a really great choice. But remember with this condensing model I’ve got condensate that I’ve got to deal with.
If I’m building new, I can put a drain right there, I can deal with it. If I’m retrofitting that condensate can be hard to deal with especially if you’re outside because you’ve also got to neutralize that. The condensate out of this unit is going to have a PH between 3 and 5 which means it’s pretty acidic and we can’t just dump that on the ground, it’s going to kill everything. That acid is not good for your plants. You’re going to have to have a special unit that’s going to neutralize that.
That’s what brings me to these right here. These units, which are what’s called mid-efficiency, single stage, you’ve got different venting for these but you don’t have any condensate to deal with so if you’re remodeling or retrofitting I really think that the mid-efficiency models are the way to go.
Thanks for joining me on this deep dive into tankless water heaters and big thanks to More Supply for letting me use their warehouse today to film this video. Guys, for more information on this topic go check out my blog at mattrisinger.com, I love talking about water heaters, there’s so much to talk about and there’s so many options out there today.
But today’s episode was really meant to talk specifically about gas and tankless. Stay tuned for more on this topic in the future. Hit the subscribe button if you’re not currently a subscriber.
