00:00:00
- Both of the RVs that
we've had, our 397TH
00:00:04
that we got back in 2017
00:00:06
and this 410TH that we've had for, gosh,
00:00:09
I guess it'll be about
a year and a half now,
00:00:12
have had a standard tank water heater.
00:00:14
In fact, both of them had
the exact same water heater,
00:00:17
which is a 12 gallon
Suburban water heater.
00:00:20
That is propane and or electric.
00:00:23
I say and or because you
can actually use both
00:00:26
at the same time to kind of
double your heating capacity.
00:00:29
And at 12 gallons it
is a little bit larger
00:00:32
than you'll find in a lot of RVs.
00:00:33
A lot of RVs with 10 heaters
have 10 and eight gallons,
00:00:36
but Suburban does also make a 16 gallon
00:00:38
so we're not at the largest end.
00:00:40
But my point is we have
a little bit larger tank
00:00:42
and we can take quite a long shower
00:00:44
with 12 gallons of hot water.
00:00:46
However, we do have to kind
of time things sometimes.
00:00:49
You don't want to take
showers back to back
00:00:51
because the second person's
gonna run outta hot water.
00:00:54
And of course, you know, washing dishes,
00:00:56
doing a hot load of wash,
et cetera, you get the idea.
00:00:59
So we've always been curious
00:01:00
about the on-demand water heaters
00:01:03
that have this unlimited
supply of hot water.
00:01:06
And as it happens, we just
recently traveled in an RV
00:01:10
with an on-demand water heater
00:01:12
and our experience was
a bit of a mixed bag.
00:01:16
So while we have both RVs
here together, I wanted
00:01:20
to do some side-by-side experiments
00:01:22
and actually take some
measurements and see what's what.
00:01:24
If you're curious what
the RV is, why we have it,
00:01:27
why we traveled in it,
well, that's top secret
00:01:29
and you're gonna have to subscribe
00:01:31
and click that notification bell
00:01:32
so you can follow our travels
when we get to that RV
00:01:36
and see what's going on there.
00:01:37
Before we get into the tests, I'd like
00:01:39
to just cover some basic concepts
00:01:40
and also the specs of these water heaters
00:01:43
so we know exactly what we're testing.
00:01:45
So first off, you have your
standard tank water heater.
00:01:48
It's just like the kind you
might find in your house.
00:01:51
It has a tank of water that
gets heated to like, you know,
00:01:54
135 or so degrees,
00:01:56
and that water is hot and
ready anytime you need it.
00:01:59
As soon as you turn on the
faucet, all you're waiting for
00:02:02
is for the hot water to
get from the water heater
00:02:05
to your tap.
00:02:06
The drawback is you are limited
to that tank size capacity.
00:02:10
Once you're out of hot
water, you do have to wait
00:02:13
for a recovery, which is
just the heating back up
00:02:15
of the cold water that
replaced the hot water.
00:02:17
Now a tankless or on-demand water heater
00:02:20
is kind of just like it sounds,
00:02:21
it doesn't have a tank at all.
00:02:23
It heats water on-demand as
the water's flowing through it.
00:02:26
The key here is since the water isn't hot,
00:02:29
sitting there ready,
00:02:30
it has to detect flow
before the burner kicks on
00:02:32
and you have a little bit more
00:02:34
of a delay in getting
hot water to your tap.
00:02:37
On the upside,
00:02:38
once you get that hot water
running, it's unlimited.
00:02:42
You can just hot water, hot
water, hot water all day long,
00:02:46
as long as you have the fuel to do so.
00:02:48
And that brings me to the
other point about these
00:02:50
is the only ones that I've
seen for RVs are propane only.
00:02:55
I think propane provides a high enough BTU
00:02:58
to heat water that fast.
00:03:00
I'm not sure if there are any
full electric ones out there.
00:03:03
I would think they would
have to be 240 volt,
00:03:06
and I'm not real sure how
feasible that is in an RV,
00:03:09
it'd probably take a lot of
juice to heat water that fast.
00:03:11
So with that, the other
downside to having propane
00:03:14
as its primary fuel source
is you can't take advantage
00:03:17
of the free electricity
that's usually included
00:03:19
with your RV site.
00:03:21
So let's talk about the
specs of these two units
00:03:23
that we're going to test.
00:03:25
In our 410, which was also in our old RV,
00:03:28
we have a Suburban 12 gallon.
00:03:31
It's the SW12DEL.
00:03:33
And the propane side of that
heater is rated at 12,000 BTU
00:03:38
with the electric side
rated around 7,200 BTU.
00:03:41
So combined, you've got
about 19,200 BTU of energy
00:03:47
to heat that 12 gallon tank.
00:03:48
Those BTU ratings aren't really critical
00:03:51
in comparing these two.
00:03:52
It's really apples to oranges
00:03:54
when you're talking about BTU
ratings of a water heater,
00:03:58
tank versus tankless,
00:03:59
simply because the heating
elements only go into play
00:04:03
when it's reheating water in the tank
00:04:05
and the recovery cycle
for that particular unit.
00:04:08
So a higher BTU's gonna get
you a faster recovery time,
00:04:11
but it's not gonna get
you hot water faster
00:04:14
or more hot water to your tap.
00:04:16
And that brings me to the tankless.
00:04:19
On a tankless, the BTU
rating really matters
00:04:22
because it's heating the water as it goes.
00:04:24
The model that we're going to be testing
00:04:26
is the Girard GSWH-2.
00:04:29
This model is ready at 42,000 BTUs,
00:04:33
which, looking at the
different options out there,
00:04:35
it's a little bit on the smaller side,
00:04:36
but the RV that we're testing
00:04:38
is kind of an entry level unit.
00:04:39
So that's, you know, kind
of why that's in there.
00:04:41
I did also see a note on the inside door
00:04:44
of that water heater that says
between 2,000 and 4,000 feet.
00:04:48
I don't know why it stops a 4,000
00:04:49
'cause obviously if you go
higher it's gonna be even worse.
00:04:52
But because of the way
propane burns, you know,
00:04:55
it needs oxygen to burn.
00:04:57
And the higher you go in
elevation, the thinner the air is,
00:04:59
the less oxygen there is
00:05:01
and the lower BTU rating you're
gonna get out of propane.
00:05:04
And that's true for all
propane burning devices,
00:05:07
whether it's your water heater
or your furnace or whatever.
00:05:10
Anyway, this note inside
the little door said that
00:05:14
2,000 to 4,000 feet, you're
gonna get about 37,000 BTU
00:05:18
versus the 42,000.
00:05:20
Obviously that's just kind of a notice,
00:05:22
it's a gradual scale.
00:05:24
If you go above 4,000, 5,000, 6,000,
00:05:27
it's gonna be even less than that.
00:05:29
For our testing, we are at
almost exactly 2,000 feet
00:05:33
so do keep that in mind.
00:05:34
This thing is really going to be
00:05:35
less than the 42,000 that it's rated for.
00:05:38
And since I'm talking
about this BTU measurement,
00:05:40
I did look up the units
00:05:43
that are going into
larger RVs like our 410.
00:05:46
New 410s that are coming
out now do have a 60,000 BTU
00:05:51
on-demand water heater by Furrion.
00:05:53
We don't have that one to test.
00:05:54
But just know that as we're testing this,
00:05:57
if you've got that model or one like it
00:06:00
that's 60,000 or higher
BTU, you know, it's going to
00:06:04
probably heat up just a little bit faster
00:06:06
and have a higher limit as far as
00:06:09
how hot you can make your water.
00:06:11
So with these differences
in operation in mind,
00:06:13
we can make a few assumptions
that we're gonna test.
00:06:16
Number one, a tank heater is gonna have
00:06:19
less wait time for hot water.
00:06:21
However, you are limited
on the quantity of water
00:06:23
based on the size of your tank.
00:06:24
Whereas on the tankless
you've got instant hot water,
00:06:28
but you're probably gonna have
to wait a little bit longer
00:06:30
for that hot water because the burner
00:06:32
and everything has to fire up
00:06:33
and get to heat while the
water's already flowing.
00:06:36
And I think you're gonna see in our tests,
00:06:37
there are some other caveats as well.
00:06:39
With those differences in
mind, here are some tests
00:06:41
that I wanna do and actually quantify.
00:06:43
Number one, I wanna
measure how long it takes
00:06:46
to get water to the tap.
00:06:48
That can be a big factor
when you're boondocking,
00:06:50
or even just partial hookups.
00:06:52
Along with that, I'll want to test
00:06:54
how much water is wasted while
you wait for the hot water,
00:06:58
and how does that wait
and delay affect tasks
00:07:02
where you might want to turn your water
00:07:03
on and off frequently,
00:07:05
like maybe when you're
washing dishes boondocking,
00:07:08
or when you're taking a navy shower
00:07:10
when you're boondocking,
00:07:11
you're turning that water off and on.
00:07:13
How does it handle that?
00:07:14
What are the repercussions?
00:07:15
I'm also curious, when
you're on a tankless heater
00:07:18
that's heated by propane,
00:07:19
you've got unlimited hot
water like I mentioned,
00:07:22
but how much propane does it burn
00:07:23
for, say, a 15 minute shower?
00:07:25
So let's go run these tests
00:07:26
and then we're gonna go over the results
00:07:27
and see what's what.
00:07:29
And we'll also maybe have some
tips based on what we find.
00:07:33
Alright, our first test is going
to be our initial flow test
00:07:36
and that is how long does
it take to get hot water
00:07:39
to the faucet after we turn it on?
00:07:42
Also, for all of the
tests we're doing today,
00:07:44
I wanna set a baseline
00:07:45
of what our source water temperature is,
00:07:48
and it's pretty cold.
00:07:50
So right about 56.5 degrees
there for our source water.
00:07:55
So our first test is duration
00:07:57
and how much water is wasted
getting hot water to here.
00:08:03
Ready, go.
00:08:11
Ooh, cold.
00:08:14
It's like 54, 55.
00:08:16
It got a little colder.
00:08:17
Starting to get warm.
00:08:20
80s, 90s, 102, 104, 110,
00:08:25
11, 12, 13, 14, 15, 16.
00:08:30
So right, 117, so that's
good enough for dish washing.
00:08:35
That took about 32 seconds,
and we used 1.75 liters.
00:08:42
Now the second test I want to do is to see
00:08:45
how it handles the cycling of water.
00:08:48
And what I mean by that here at the sink
00:08:50
is you're washing dishes,
00:08:52
now you're gonna have your
hot water on for a bit.
00:08:55
You might wash some dishes,
00:08:57
you might shut it off to
do stuff, turn it back on.
00:09:02
How long has it taken between those,
00:09:04
and is there any break from
the hot water coming out?
00:09:07
As I suspected when cycling
the water on and off
00:09:10
with 30 second breaks in between,
00:09:11
there was virtually zero eight
time for hot water to resume.
00:09:16
Now we want to go to the shower
00:09:18
and do a similar test that we did here.
00:09:20
And that's gonna be a little different
00:09:22
'cause that's gonna be
a mix of hot and cold,
00:09:23
'cause your average water temperature
00:09:25
for a shower is gonna be
between 105 and 110 degrees,
00:09:29
per the interwebs.
00:09:30
So let's head in there and test that out.
00:09:32
In the bathroom of our 410TH,
I did the same time delay
00:09:37
and wastewater volume test
that I did in the kitchen sink.
00:09:40
Because the bathroom is
directly above the water heater,
00:09:43
it only took 15 seconds to get hot water
00:09:46
and a little bit less than a
liter of cold water was wasted.
00:09:50
I also did the test cycling
water off for 30 seconds
00:09:52
to back on, and the delay was negligible,
00:09:55
with only about two seconds of warm water
00:09:57
before it was hot again.
00:09:59
I did that test three times to make sure.
00:10:02
Next up is to test the recovery time.
00:10:04
I'm going to run this shower on full hot
00:10:08
until the hot water's all gone,
00:10:10
because I want to test how long it takes
00:10:12
to fully recover the water heater.
00:10:14
After the water heater's fully recovered,
00:10:16
then I will do a duration test
00:10:18
and see how long that 12 gallons
00:10:20
of fully heated water lasts.
00:10:22
Alright, ice cold water
coming out of the hot side.
00:10:27
The water hater has been
off, as you can see here.
00:10:31
Now I'm gonna turn on the
electric and gas together.
00:10:35
Like I mentioned, they
can be run simultaneously
00:10:38
for the fastest recovery.
00:10:39
And that's what I want to test here.
00:10:50
Oh, just finished.
00:10:53
38 minutes for full recovery.
00:10:55
So we've got 38 minutes for
a full recovery on that.
00:10:59
Now we're going to see how long
we can actually run a shower
00:11:04
on that 12 gallons we just heated up.
00:11:06
I ran the shower, making adjustments
00:11:08
to the hot-cold mix as the
water started to get used up
00:11:11
and a little bit diluted with cold water,
00:11:13
'cause that's just how you
really take showers, right?
00:11:15
You have to adjust the water
as the temperature goes down.
00:11:19
Since we're getting low, okay,
it's all the way hot now,
00:11:23
it's all the way hot and
we're getting in the 90s.
00:11:26
So I'm considering this test done.
00:11:28
So shower length test, right
about the 16 minute mark
00:11:32
is where we started to lose hot water
00:11:34
and had to start really
adjusting the hot water mix
00:11:38
up quite a bit.
00:11:39
So we're gonna call it 16 minutes.
00:11:43
Okay, we are over here in our test unit
00:11:46
that we're not going to
disclose until later.
00:11:48
But this one has the
on-demand water heater.
00:11:51
So I'm gonna do some
of the same tests here.
00:11:54
Of course, the first one
I wanna do is our duration
00:11:56
to get hot water, and then
we'll see how hot it is.
00:12:00
The maximum set temperature
00:12:01
for this particular model is 124 degrees.
00:12:05
I imagine that would be a bit higher
00:12:08
if we were on a 60,000 BTU system,
00:12:11
but this 42,000 BTU
system is what we've got.
00:12:15
So let's do the same test.
00:12:17
We're gonna test how
much wasted water we get
00:12:19
and we're going to see what
our final temperature is
00:12:22
and how long it takes to get there.
00:12:23
I'm gonna flip this all the
way over to hot, and go.
00:12:29
I hear the thing firing up.
00:12:31
So we'll see more of what this thing does
00:12:33
when we go do some tests in the bathroom,
00:12:35
as far as the stages that it goes through.
00:12:37
Still really cold.
00:12:39
Again, our shore water
here is pretty cold.
00:12:42
Right now I'm getting 62 degrees.
00:12:51
Still cold at 30 seconds,
starting to warm up.
00:12:55
80 degrees, 83, still not
warm enough for dishes.
00:12:58
88, more like hand
washing temperature now.
00:13:03
97, 98, 99, 100.
00:13:07
And now we're at the
point I feel, it's 102,
00:13:09
now I feel like we are
where we could wash dishes.
00:13:12
So let's shut that off.
00:13:14
And that took almost a full minute.
00:13:17
That was about 55 seconds
to get hot water here.
00:13:22
Just barely shy of two and a
half liters of wasted water
00:13:30
for this to heat up.
00:13:31
So I want to test intermittent use.
00:13:34
Before testing intermittent use,
00:13:35
I got the water flowing
at maximum temp again,
00:13:38
shut the water off for 30 seconds,
00:13:39
then turned the hot water back on.
00:13:41
I repeated this test three
times with the same results
00:13:44
of about 55 seconds.
00:13:46
So when cycling, you get
some initial hot water
00:13:48
from the lines, but then it goes cold
00:13:51
and does take about 55
seconds to heat up again,
00:13:53
each time wasting about
two and a half liters.
00:13:56
I think maybe for washing dishes
the best approach might be
00:13:59
to fill a sink or tub with
hot water, wash your dishes
00:14:01
and save all the rinsing till the end.
00:14:04
But you can see a lot of water
00:14:06
and time is wasted if
you need to cycle water.
00:14:08
Now on to the bathroom tests.
00:14:10
Okay, time for a shower
test with the on-demand.
00:14:12
Now one of the advantages of an on-demand
00:14:16
is you can actually set
your output temperature
00:14:18
and this thing should maintain it.
00:14:20
Now, what we've heard from
people who have this system
00:14:23
or a system like it
00:14:24
is that rather than have
your hot water set on maximum
00:14:27
and be like around 124, whatever,
00:14:30
this thing says 124 is its max,
00:14:32
you can set the temp to
something closer to like 109
00:14:37
and then you have the
option of, at your shower,
00:14:40
you can just turn on the hot water
00:14:41
or turn it on all the way hot
00:14:42
depending on how your controls are
00:14:44
and get that output temperature
and just keep it there
00:14:48
rather than having to do
the hot-cold mix thing
00:14:51
where you have this at maximum.
00:14:52
So I'm gonna have that set at 109,
00:14:54
and we're gonna see how long
it takes to get water here,
00:14:59
just 'cause it'll be easier
to test the temperature
00:15:03
and stuff coming outta the
faucet versus the shower,
00:15:05
and they're right next to each other,
00:15:06
I don't think there's
gonna be a big difference.
00:15:08
So I'm gonna use the sink
to test our output here.
00:15:11
Three, two, one, go.
00:15:17
I hear this thing kicking in.
00:15:18
We got hot water pretty quick that time,
00:15:19
but I think it has some
water in the lines.
00:15:21
111, nope, cold again, back
to that down 70, 69, 70, 79.
00:15:27
Now it's popping back up.
00:15:31
95.
00:15:33
Let's see if we hit our actual 110.
00:15:35
The display here shows me
it's getting up to 106, 108.
00:15:40
Okay, there's 108, I'm
seeing 102 at the faucet.
00:15:46
Now this is telling me 109.
00:15:54
This is telling me 109.
00:15:58
I'm getting about 106, 107 out
00:16:00
so it's cooling down a couple of degrees.
00:16:03
So as you can see, it took
about 45 to 50 seconds
00:16:06
to get water from the
tank to the bathroom.
00:16:10
A slight improvement over
the kitchen to the bathroom
00:16:12
simply because it's shorter
distance of water lines.
00:16:16
The intermittent cycling tests
were pretty much the same,
00:16:18
taking about 45 to 55 seconds
to get hot water to the tap,
00:16:23
the difference being that it
would get warm or hot first
00:16:27
because of the water in the
lines, followed by cold water,
00:16:31
and then it would get hot again.
00:16:33
So it would seem that a
navy style shower in an RV
00:16:37
with a on-demand water heater
is really pretty impractical.
00:16:42
Now on the test that I wanted to run
00:16:44
of how much propane is
used in a tankless heater
00:16:47
for a 15 minute shower
in this particular unit,
00:16:50
I wanted to use those same
little weighing hanging things
00:16:54
that I used when I tested
the Mopeka sensors.
00:16:57
If you didn't see that video,
I'll link it down below.
00:16:59
That's where I actually
tested the accuracy.
00:17:01
Long story short, they're super accurate,
00:17:03
so I kind of punted
and decided to go ahead
00:17:06
and use those to measure.
00:17:08
It isn't perfect, but I was
able to do a 15 minute test
00:17:12
and I was able to detect
a 0.7 centimeter drop
00:17:17
in the propane levels.
00:17:18
Now that doesn't mean a whole lot,
00:17:21
so I did a little bit of math
00:17:22
and that comes out to about
536 cubic centimeters,
00:17:27
and that converts to about 0.14 gallons.
00:17:31
Knowing a 30 pound tank
holds about seven gallons
00:17:33
or 26.5 liters, we can estimate you'd get
00:17:37
about 50 15 minute showers
out of a 30 pound tank.
00:17:42
Again, that's a very rough
estimate, but that's pretty good.
00:17:46
You know, you've got two 30 pound tanks,
00:17:47
100 15 minute showers, that's not bad.
00:17:50
But for those of you who
are out there using this
00:17:52
in real life, I'm curious what
your anecdotal evidence is.
00:17:57
What are you seeing as far as propane use
00:17:59
for your on-demand water heater?
00:18:01
So let's put up our final testing results
00:18:03
here on the screen.
00:18:05
This little graph you see
here will also be available
00:18:07
in the blog post if you want
to go back and look at it
00:18:09
versus just pausing it.
00:18:11
And you can see that the
tank standard water heater
00:18:14
wins in almost every category.
00:18:17
The only exception is when you're able to
00:18:21
have water flowing constantly,
00:18:22
and not worry about how
much water you're using,
00:18:25
AKA on full hookups with sewer.
00:18:28
The tankless doesn't
seem to perform very well
00:18:31
when you have to ration
water, AKA boondocking,
00:18:34
partial hookups with no sewer.
00:18:37
Whenever you've got to ration your water
00:18:39
and cycle water on and off,
00:18:40
the tankless is definitely a detriment.
00:18:43
If you do have to boondock
with a tankless heater,
00:18:46
here are some tips that might help.
00:18:48
Number one, when you're washing dishes,
00:18:51
maybe catch that initial
two and a half liters
00:18:53
or whatever you get of
cold water in a bucket
00:18:56
and then set it aside.
00:18:57
And then you can use that water
00:18:59
for extra water in the
toilet when doing number two,
00:19:03
brushing your teeth,
00:19:04
heck, you could even take that water
00:19:06
and siphon it back into
your fresh water tank
00:19:08
and use it later.
00:19:09
In the shower, maybe just try to be
00:19:11
really, really super fast,
practice your speed washing,
00:19:14
or maybe do it in just two
cycles, like I mentioned,
00:19:16
one long wet cycle, soap,
wash hair, all that stuff,
00:19:21
one long rinse cycle and done.
00:19:23
But let us know your
tankless water heater,
00:19:27
tips down the comments below,
00:19:28
people love to read through those.
00:19:30
A lot of you guys have some great tips,
00:19:32
so be sure to put those down below.
00:19:34
At one point we were actually
considering swapping out
00:19:37
our tank water heater for
that Furrion 60,000 BTU system
00:19:43
just because we wanted to try it out.
00:19:45
Thought, you know, that
sounds really cool.
00:19:46
But after our experience in this other RV
00:19:49
and these tests, I think we're gonna stick
00:19:52
with our Suburban 12 gallon heater.
00:19:54
Let us know what you
think about all, hold on.
00:19:57
I know you think it's
the end of the video,
00:19:59
but I got one more thing
to show you. (chuckling)
00:20:02
I was out here filming
some B-roll for this video,
00:20:04
and when I was doing some
of my filming, I noticed
00:20:08
that I couldn't get the
temperature to go above 86 degrees.
00:20:12
And I was actually measuring
more like 82 degrees
00:20:15
coming out of the tap and now
it's as high as it could go.
00:20:18
So I tested the temperature
of my source water,
00:20:21
which is now the tanks, and my
source water was 39 degrees.
00:20:25
I was on shore water
00:20:27
when we were doing the
testing from our cabin.
00:20:28
That water was I think around high 50s,
00:20:31
somewhere around there, I forget.
00:20:32
But my point here is the
BTU rating really matters
00:20:38
if you're gonna camp in cold temperatures.
00:20:41
We've got our tank heaters
on, we've got the furnace on,
00:20:44
not as high as we would if
we were staying in this unit,
00:20:47
but high enough to keep
things from freezing.
00:20:50
And with that source
temperature down to 39 degrees,
00:20:54
the water in here is unusable.
00:20:56
There just is no hot
water above 86 degrees.
00:21:01
Let us know what you think about all this
00:21:03
down in the comments below.
00:21:04
Please don't forget to
hit that like button
00:21:06
and subscribe if you haven't already,
00:21:08
and we'll see you next week.
