We all love having warm and hot water at home. One thing that many homeowners don’t realize is that there are several types of water heaters out there. The most fuel efficient type has to be the tankless variety. Basically, without a tank, this appliance heats water as it’s drawn and shoots it to all parts of your home. It’s important to note that with gas-powered tankless heaters, you need to have proper ventilation space get rid of poisonous fumes in case of gas leaks.
This time around, we’re going to look at two of Takagi’s most popular, best-performing gas-fired water heaters – the T-KJr2-IN-NG and the T-KJr2-IN-LP. These gas heaters use natural gas and liquid propane, respectively, to heat up water with its coils. Before purchasing one or the other, make sure that your home is supplied either natural gas or propane, otherwise, you’ll be left with a rather expensive paperweight. Let’s get right to our comparison.
The energy factor (EF) of a water heater shows its fuel efficiency. It basically shows how efficiency water is heated from the energy source (in the case of these two models, natural gas or liquid propane). The NG model has an EF range of between 0.81 and 0.83. This is about the industry average for natural gas-powered tankless water heaters, and it’s actually a very fuel-efficient number.
The LP model, on the other hand, has a low 0.80 EF rating. The average EF rating for tank water heaters is roughly 0.5, so it’s clear that with either of these models, you’ll end up saving much more in the long run. At 0.8, you’ll hardly be using any propane to supply properly heated water throughout your home.
You can use an online calculator to determine more accurately how much you’ll end up spending on fuel to power either of these models. However, looking at this purely from the EF rating, the NG model is more fuel-efficient than the LP one, though the difference is extremely marginal.
T-KJr2-IN-NG and T-KJr2-IN-LP
Depending on how warm or hot you want your home’s water to be, you need to adjust the BTU setting of your tankless water heater. Both of these models feature a BTU range of between 19,500 and 140,000 BTU, meaning that you’ll be able to get water heated up to 160° F at any given time. Of course, the higher you set the BTU count, the more gas is used. In addition, both of these units come with remote controls which let the user configure the BTU setting (extra convenience).
Even though there’s no difference in BTU between these two models, it’s still an important factor to consider when looking for a gas tankless water heater.
T-KJr2-IN-NG and T-KJr2-IN-LP
The gallons-per-minute (GPM) rating shows how much how water can be supplied at any given time. Generally speaking, the higher the GPM rating, the more powerful the unit is at providing a constant flow of heated water. Once again, both of these models feature a similar spec – a maximum water flow capacity of 6.6 GPM.
However, the maximum of 6.6 GPM doesn’t mean that it can supply 160° F-water at a rate of 6.6 GPM, but rather the unit will only reach around 120° F at the mentioned flow rate. This isn’t an issue at all since most home appliances don’t need water to exceed 140° F.
There are several online calculators you can use to determine how much flow of hot water you use. For example, for cooking purposes, a kitchen’s sink faucet will have a rating of around 1.5 GPM, and shower heads will need around 4 GPM. With a total of 5.5 GPM, both of these models can supply sufficient heated water for both water uses.
These models use coils to heat up water as it’s drawn from the source before supplying it throughout your home. The only drawback of tankless water heaters is that there’s a waiting period between opening the hot water valve and actually receiving heated water. This natural gas model has an unofficial recovery rate of around 10 seconds. The longer the recovery rate is, the more water you send down the drain before heated water comes shooting out of your faucets.
The liquid propane model is a little more efficient than the natural gas one. On average, users have reported a wait or recovery period of around 5 to 6 seconds before feeling the heat come through their faucets. Even though 4 seconds may not sound like much, in the long run, you’re wasting less cool water while waiting for heated water to come.
Between natural gas and propane water heaters, propane heaters are naturally more efficient at providing heated water. There’s no way around it unless you get a tank water heater which runs off of natural gas (heated water all day long). However, that is something that the T-KJr2-IN-NG is not.
Takagi T-KJr2-IN-NG vs T-KJr2-IN-LP: Bottom Line
Between these two models, you’re not going to find many differences. Essentially, Takagi built the same unit twice, but each version is supplied using a different form of gas. This is done to cater to both markets where each uses either natural gas or liquid propane for heating homes. Other than the different gas types, there are not going to be any differences in terms of specs.
However, performance-wise, the liquid propane version model wins simply based on the fact that liquid propane is innately much more efficient at heating water than natural gas is. This doesn’t mean that the natural gas version is significantly worse than its liquid propane counterpart, but rather homes that use liquid propane exclusively will end up spending less in the long run for water-heating applications.
Tankless water heaters have innate drawbacks, including their inability to provide heated water as soon as the hot water tap is opened, leading to wasted water than can be expensive over time. However, fuel-wise, gas-powered water heaters are more efficient than their electric-powered or tank counterparts.