Hot shower system plumbing

[jorgito]

I purchased helton heat exchanger from Kurt and I am planning to do the installation this month. I was looking around and I really like the installation as it is done here:

http://www.expeditionportal.com/forum/threads/72802-On-Board-Hot-Water-Shower-System/page3

Basically I would like to duplicate the same setup.

• helton heat exchanger
• valterra abs water tank
• two shurflo water pumps

One water pump should be used to circulate the water threw the heat exchanger the second pump would be for the shower / kitchen itself. My question - as I never did anything with plumbing is: what type of water pipes do you recommend and what fittings should I buy ? The shurflo's have 1/2'' while helton has 3/8. The pipes should be flexible enough as I will need them to go around the engine department and under or around the frame. Shall I use flexible pipe in the engine department and then change to PEX on the frame to the water pumps ?

Please advice.

Thanks,

Jorge

 

[Haf-E]

I don't think Shurflo makes a pump suitable for circulating the hot water through an exchange - but I might be wrong on that - most people use a solar hot water circulator pump instead...

The shurflo pump would just pressurize the hot water tank so it only has to pump cold water into the tank / exchanger - not hot water.

For the pipes in the engine compartment I would look at heater hose as it is designed to handle that environment. For the shower side of the tank, PEX would be good.

 

[Sabre]

The best thing to use will be from a marine supply store. If you don't have one near you they can be ordered online. The ones in the photos in that thread you linked are reinforced PVC, which are available in a variety of styles and sizes. Make sure that they're approved for use with pressurized hot and cold water systems. You don't need a wire reinforced hose since they will not be subject to vacuum. Examples of such hoses are Shields 162, 164, or 168 series or Trident 161 or 162-164 series. The hose looks similar to this:

You can use brass or plastic barbed connectors with simple hose clamps. Be aware that the plastic connectors are more likely to fracture with impact or repeated stress, so bear that in mind.

 

[jorgito]

According to specs the shurflo pump can handle temps till 54 degrees which is more then sufficient for hot shower. This is from all knowing google:

Please keep in mind that most people take their showers and hot baths in temperatures ranging from 38-42 degrees Celsius. Our standard body temperature is 37.3 degrees Celsius, so it is advisable to start with warmer water first and then gradually lower the temperature until 10-15 degrees Celsius is reached.Feb 15, 2011

LIQUID TEMPERATURE: 130 Degrees Fahrenheit (54 Degrees Centigrade) Max

One pump will just circulate the water threw heat exchanger. My question is not related to the plumbing of the coolant lines but the water lines going from the helton to water tank/ pumps.

Thanks,

Jorge

 

[Haf-E]

I guess I don't understand how your system will work then - most of the setups I have seen use a circ pump to carry the water from the tank to the heat exchanger and then back - and then they store the hot water. It sounds like you will be doing a system which only has a cold water tank and then will pump the cold water through the heat exchanger with the engine running?

If a system with a circ pump and a hot water storage tank was used you would end up with much hotter water than 60C / 130F - so it would also require a mixing valve / tempering valve. The benefit is that you would have hot water with the engine off.

I guess I misunderstood...

 

[jorgito]

Hi Hafe ,

yes that's right. I will have just one tank. The benefit is the ease of use / implementation by not using any heat valves etc. The system would be used only for showers and kitchen so it doesn't have to be hot hot hot.

Regards,

Jorge

 

[jorgito]

Sabre,

thanks for your info. That's what I was missing. I found hose like this one:

http://www.fisheriessupply.com/trident-marine-reinforced-pvc-in-red-tracerin-hose-fda-approved

Seems that it should be fine.

Jorge

 

[jorgito]

I am not sure if it is fine to have the water pumps exposed under the frame. In case of water crossings wouldn't the pumps be destroyed ?
I am thinking about putting them into this box:

https://www.polycase.com/yq-100806?

It's basically weather resistant electronic box.

Jorge

 

[Sabre]

You're very welcome. My thoughts about the pump include mounting it up high in the engine compartment and/or using one that is submersible, such as this one: http://www.amazon.com/Yosoo®-Solar-Water-Circulation-Brushless/dp/B00DWORE5A

 

[Haf-E]

That Yosoo pump is more of a circulating type pump and will not give much water pressure. They also do not self prime so they need to be lower than the water tank. The Shurflo type pump will give descent pressure (~30 psi usually) and is able to self prime - so it can be higher than the tank - but not much higher (i think within 2 feet of the tank?). The Shurflow would not survive under the truck in the case of a water crossing - and I doubt of that cheap Yosoo pump would last very long regardless of where it is mounted based on its price...

 

[Ozarker]

I'd suggest using PEX for all your plumbing, except drains. Someday you'll have water in the lines and it will freeze, PEX won't burst it just bubbles up. Use a heating pad with water storage or drain it and open all the valves. Plastic ties underneath should keep your PEX secured, there are special clamps you might use for longer runs, don't over tighten the clamps and keep the clamp tool (required) square to the work otherwise it can leak. Just read the instructions. See if you can run lines inside the framing.

Those are nice setups, but for simplicity and no/low maintenance I think I'll go with a solar bag or just heat some water.

 

[jorgito]

Do you guys think that I will need to vent the ABS water tank ? I don't think that there will be such high pressure to need a vent.

 

[IdaSHO]

Every tank needs some sort of vent.