How Long Can You Shower? Hot Water Ideas?

[lornaschinske]

Maybe later. Right now I got other things to spend yet more money on. Having hot water at the washing machine isn't a big deal.

[bansil]

On tablet now so linking is tough

I have a 40 gallon twin element WH, it is hooked up for 30amp(120v) and 50amp(240v)

So far we have only used it about 2 weeks, 1 week each at 30 and 50 amp(2different camp grounds)

With 50amp service it has hot water in less than 1/2 hour, 30 amp is longer and we can pure heat going down the road

It is installed primarily for the 150 gallon tube for wifeys weekly soaking, normally showers

I did a write up in general conversion will try to link later today

We do not boondock and don't even have real holding tanks, that will change a little this spring

[family wagon]

Originally Posted by lornaschinske

Which Eco-temp did you use? The L-5? I have an L-5 that we used in the food cart. David was thinking about trying it to heat the water just for the washing machine. Never did get around to seeing it we could fit it up in the available space above the washer. Did you run it on an RV water pump? I know the one in the food cart was barely able to keep the water flow high enough for the unit to kick on. I have a slightly larger pump in the bus. Maybe next summer I will get it hooked up.

TL;DR summary: yes I have the L5; it works, but a person should have "reasonable" (limited) expectations.

I've done an experiment to put some numbers to the discussion. It's kina-sorta rigged up to model RV usage:

• deep cycle battery (cheating a bit: the charger is connected and running, is near the end of its cycle, so battery voltage is unusually high at 14.9v)
• SHURflo pump model 4008
• Ecco-Temp L5 (nameplate: 11 kW input, 1.46 GPM)
• bucket of water (4.75 gallons, 50 degrees F)
• plumbing: 1/2" vinyl tube for pump suction, faucet connector hose between pump and heater (rather small inside diameter), 1/2" PEX output. Output is elevated about 6 feet above ground level

I set the knobs on the heater for maximum heat and maximum water flow. It took 4.25 minutes to pump the 4.75 gallons and the peak output temperature was 86 F. The heater extinguished several times and I toggled its power switch to trigger re-ignition. So, I got 1.11 GPM and raised the temperature of 4.75 gallons (39.6 pounds) of water by 36 degrees F. That's 1426 Btu in 4.25 minutes, or 20131 Btu/h, or 5.9 kW. Am I doing the math right? I didn't weigh the propane to measure the consumption.. but if this heater is actually consuming 11 kW and putting just 5.9 kW into the water, I consider that lousy efficiency. Probably par for the course in traditional RV equipment, though!

I've read that the problem with the heater extinguishing is related to pressure -- that these heaters use a pressure switch, rather than a flow switch, to control the burner. I've found that I can turn down the flow knob to a point where the burner reliably stays lit, then adjust the gas knob for the temperature I want. If it's not hot enough then turn the water flow down more. I've thought about modifying the heater to use a flow switch and/or excess temperature switch but haven't spent the time to find one.

Overall... it works about the way a hundred-something-dollar heater should. For occasional or low-budget use it's definitely worth considering. But where more heat, more flow, or no-nonsense regardless of conditions are required, the L5 is not the right one for the job.

[taskswap]

Originally Posted by family wagon

I've done an experiment to put some numbers to the discussion. It's kina-sorta rigged up to model RV usage:

Nice experiment! You ever thought of a career as a MythBuster?

Yes, your math checks out. These things are definitely inefficient, but be aware that heater/boiler manufacturers are allowed to list their "maximum" output as their "rating". This number requires a special set of circumstances that usually only happen for one magical second during a heating cycle - a certain flow rate, a certain input temperature, a certain ambient, etc.

You see this with wood stove makers, too. A unit is listed as 50kBTU/hr, but puts out barely half that in normal usage. Same with cars / mpg, too. Best thing to do is divide by 2 to get a better expectation.

[superdave]

i have the same unit, love it! you may have gottin a faulty one. even in the cold months here it works great, heat on 2/3 and flow about the same. i used it in my shower to test it. it will melt your skin off on high. i went 3 1/2 months on one grill tank, shower every day sometimes 2. never had it shut down, never. still the same d batteries 9 months now.

[jazty]

Originally Posted by family wagon

...but if this heater is actually consuming 11 kW and putting just 5.9 kW into the water, I consider that lousy efficiency. Probably par for the course in traditional RV equipment, though!

Yeh, I purchased one of these and it wastes a lot of heat. You can tell just by putting your hand above the exhaust; the exhaust is extremely hot! If it were efficient the exhaust would be much cooler.

I plan on putting another heat exchange above the exhaust and power-venting it. That should suck some more heat out of the exhaust and into the water.

[ol trunt]

I use the L5 in my skoolie and like Superdave I am completely satisfied with the performance. The trick is to have a pump that will provide adequate pressure even when the water is running. Most (think cheap sticks and staples here) pumps loose pressure while the water flows which causes the heater to shut down even if flow would have been enough to keep the heater lit. As to efficiency, while there is lost heat, the heat loss only occurs while you are using the water--not while you are gone or otherwise not using hot water as is the case with any conventional water heater. Sort of hard to compare apples to apples when one of the apples is a water melon. I should mention that I am careful to turn the heater batteries off when not in use. In my experience, if the batteries are left on, they go dead in short order--no batteries, no hot water. Jack

[maggiemae]

Originally Posted by bansil

We do not boondock and don't even have real holding tanks, that will change a little this spring

Wow, how do you do this?

Everything I have read says that you need a black water tank at least, to keep the waste from drying up.

[bansil]

We only use Full hook ups, our travel days are limited to 6/8 hrs, so needing holding tanks etc isn't a priority

Last year I had the toilet dumping into 4" dia pvc that was about 8 foot run total (after the vent) so that gave us about 5 gallons of "emergency" storage that is slopped slightly and it can't dry out easily, since we will be hooked up to sewer w/i 8 hours

this spring/summer I am modifying that (since I moved toilet) to have about 15 gallons of "emergency storage"

When we are at places that do not have full hookups, we just use the bath houses

[maggiemae]

Originally Posted by bansil

We only use Full hook ups, our travel days are limited to 6/8 hrs, so needing holding tanks etc isn't a priority

Last year I had the toilet dumping into 4" dia pvc that was about 8 foot run total (after the vent) so that gave us about 5 gallons of "emergency" storage that is slopped slightly and it can't dry out easily, since we will be hooked up to sewer w/i 8 hours

this spring/summer I am modifying that (since I moved toilet) to have about 15 gallons of "emergency storage"

When we are at places that do not have full hookups, we just use the bath houses

Huh.
Do you have a photo that we can peek at, or a link to one of that setup?

I had no idea this could be done. I mean, it makes sense, but all I have read says that it's not possible.

Do you have a pressure monitor on the incoming water? Does this affect your hot water heater performance?

[bansil]

I am a little confused (and I may of added to that )

I designed our bus to hook up to either campgrounds or Mobile home/Trailer parks easily

I just screw a hose to the bus and have an 85lb reducer valve, this feeds faucets/toilet and hot water heater just like your home (cold coming in splits to sink/hot water heater/toilet and bath tub) (hot water splits and goes to sink and tub)

all drains feed into a "main drain", this main drain is used as my "emergency holding tank"

I leave the toilet bowl/tank full of clean water after we unhook, this is one emergency flush on the road (about 1 gallon) and if things are bad we can add water to the tank from the 5 gallon water jug we carry

since everything drains into the 8 ft of 4 inch pvc, I have a basic RV gate valve installed as the last pc of the puzzle (if it dripples I don't know about it)

When we get to camp spot we hook up hose to sewer and open the valve just like any other rv

I have pictures in build thread (they are old ones right now)

here are a couple that show some of the old plumbing



toilet drops into tube on right-side and goes across bus at an angle and then sink and such drop in on the left side

my next part will have the toilet drop into the left-side, go across to the right side, pickup the tub water and go back to the left-side to pickup sink and then dump valve...that sounds confusing

[ol trunt]

Bansil, have you been talking to Escher again? Your plumbing reminds me of some of his work. Jack

[bansil]

Originally Posted by ol trunt

Bansil, have you been talking to Escher again? Your plumbing reminds me of some of his work. Jack

Thanks
I needed that bit of knowledge

[thecrabshomestead]

Has anyone tried using only solar? Like the kind of solar heating one would use a black hose on top of the bus for coiled up in a circle? I would only need hot water for showers and dishes so am thinking I won't need much. Not totally opposed to propane, I just want to boondock more than hook up or worry about filling a couple of tanks. All great info from everyone! thanks!

[nat_ster]

Originally Posted by thecrabshomestead

Has anyone tried using only solar? Like the kind of solar heating one would use a black hose on top of the bus for coiled up in a circle? I would only need hot water for showers and dishes so am thinking I won't need much. Not totally opposed to propane, I just want to boondock more than hook up or worry about filling a couple of tanks. All great info from everyone! thanks!

I have seen many low buck solar water heaters work great.

Most make a shallow glass fronted cabinet to place the black copper pipe inside. This keeps the wind from cooling the heat lines.

I have been showering using a 5 gallon bucket with a lid. I painted the bucket black, and place it in a scrap car where I live. End of the day I have to cool it down a bit to keep from getting burned.

As long as it's a sunny day, I have hot water.

Nat

[taskswap]

The bucket is an important comment. To go "only solar" you need heat storage. The usual trick is a bucket or barrel of some kind. Around here people have ghetto pools and ponds where they want a quick rinse-off and they use a 50-100' length of black hose coiled on a roof somewhere. Anything that stores a lot of water will do the trick. Just be careful - it'll be SCALDING hot on a summer day. You need to be able to mix it with cold water...

Also, you need a steam vent or it'll blow open.

[bansil]

Remember to only use non transparent hose/tube, friend didn't listen to warnings and "thought" clear would work better (roll eyes)
The mold/algea and critters grew in his hoses due to the sun nourishing all things growable

[Hvbuzz]

Solar water is on my list of things to do. Probably will be awhile before I get to it, but not off my radar. Buddy of mine has a RAGBRAI bus and have been using it for years. He just has a 4 inch black pvc pipe on both sides of the bus roof top. You can see it in this pic.

Untitled by Hvbuzz, on Flickr

It's just under the deck, but still works great in summer. There is one on each side of the bus. Some day I think I will use do a similar setup but with either a 6 or 8 inch sewer main pipe (cheaper then water main, but still sealed) in a horseshoe on the roof.

[Hvbuzz]

I have a 20 gallon electric water heater and couldn't be happier. Before I leave home I have it plugged in and warmed up. Once its warmed up, it takes very little electricity to keep warm. My family of 4 can all take normal length showers in a nights time, if we are hooked up to "city" water. I would like the solar water for the extra water capacity.

[thecrabshomestead]

Originally Posted by nat_ster

I have seen many low buck solar water heaters work great.

Most make a shallow glass fronted cabinet to place the black copper pipe inside. This keeps the wind from cooling the heat lines.

I have been showering using a 5 gallon bucket with a lid. I painted the bucket black, and place it in a scrap car where I live. End of the day I have to cool it down a bit to keep from getting burned.

As long as it's a sunny day, I have hot water.

Nat

I have seen a few solar water heaters with the glass and they used black rubber hose or the copper pipe painted black. I also saw a solar water heater kit that works with a normal RV water heater (6-10 gallon propane or electric) and you just will switch over to the RV one if you are out of solar water. I am definitely looking at this glass case option. WE will only need it for showers honestly..but I do want to be able to plug in somewhere and just get it when I want it lol. Maybe I will find a 6-10 gallon propane/electric one and add the solar as my main option. Either I am learning a lot from all of your feedback! Thanks!