Which Is The Best Tankless Water Heater System To Buy?
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.