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-   -   Heated Towel Rack By-Pass (https://www.airforums.com/forums/f540/heated-towel-rack-by-pass-214719.html)

BryonJ 09-23-2020 03:41 PM

Heated Towel Rack By-Pass
 
Anyone thought of or has completed a by-pass to the heated towel rack on the 33í Classics?

If we set the Alde thermostat control to use the bedroom thermostat, the back of the trailer gets rather warm. Typically we set the bedroom to 67 at night, yet on cool nights the living room stat will read 74.

Two parts to the problem, I believe. First, the bedroom is at the end of the glycol loop. Second, the towel rack is a lot of exposed hot tubing that heats up the bathroom.

It seems that if we by-passed the towel rack we could minimize heat loss in the glycol at the back of the trailer. Also with less surface are to exchange heat, the back of the trailer would not get so hot.

Thanks for any comments or suggestions.

By the way - the Alde hydronic heat is just awesome.

BigSxyWhtGuy 09-23-2020 04:23 PM

How about turning down your circ pump, allow the fluid more time to heat and circulate?

You could also temp the air next to the vents to check temp. You should only have a small variation between the front and the back. Our 30 is within a few degrees difference between front and back.

May also be able to set up a very small fan to increase air circulation from back towards the front?

If you wanted to bypass the towel bar, Iíd just save it as a last case scenario.

BryonJ 09-24-2020 08:22 AM

Good thoughts but the 33í is entirely different than the 30í this way. The exposed towel rack is a lot of surface area at the beginning of the loop. No matter what you do with thermostats, pump speed, etc, the glycol will lose a lot of heat into the bathroom.

I might try to speed up the pump; however, the towel rack is about 8í of exposed pipe, so I donít think it will have much Impact.

Perhaps as a trial I could insulate the pipe?

Quote:

Originally Posted by BigSxyWhtGuy (Post 2413902)
How about turning down your circ pump, allow the fluid more time to heat and circulate?

You could also temp the air next to the vents to check temp. You should only have a small variation between the front and the back. Our 30 is within a few degrees difference between front and back.

May also be able to set up a very small fan to increase air circulation from back towards the front?

If you wanted to bypass the towel bar, Iíd just save it as a last case scenario.


BigSxyWhtGuy 09-24-2020 09:16 AM

The 30 has the same towel bar.

Your alde system is under your dinette as is mine, are you sure your flow goes to the rear of the trailer first or does it flow the opposite direction? Iím not certain of that fact.

I believe mine goes in an anti clockwise flow but now that it is brought up, Iím not certain. In your case it matters as it changes the theory. If the towel bar is hot at the end of the loop then your challenge isnít with the towel bar but with something else.

BryonJ 09-25-2020 08:57 AM

You are correct, the Alde is under the dinette. The flow is from the dinette to the rear of the trailer, around the back up to the front then on the door side it loops back around to the dinette. It does not cross the door.

Slowing the pump will not help as it is not a glycol temperature issue, rather a heat transfer issue. The exposed pipe of the towel rack is just too much surface area. The glycol retains plenty of heat when it gets to the front bedroom, it has just "given" the bathroom a lot more than it needs.

That said, the system works great and I would never trade it for the traditional propane forced air heaters.

Like in all things RV - you have to find a balance. If I set the the Alde thermostat to "sofa" the back stays comfortable, but the bedroom gets a bit cool. I guess that's why Airstream provided a nice comforter for the beds😉



Quote:

Originally Posted by BigSxyWhtGuy (Post 2414123)
The 30 has the same towel bar.

Your alde system is under your dinette as is mine, are you sure your flow goes to the rear of the trailer first or does it flow the opposite direction? Iím not certain of that fact.

I believe mine goes in an anti clockwise flow but now that it is brought up, Iím not certain. In your case it matters as it changes the theory. If the towel bar is hot at the end of the loop then your challenge isnít with the towel bar but with something else.


BigSxyWhtGuy 09-25-2020 01:26 PM

Cool, sounds like your mind is set on bypass or insulation. Good luck, let everyone know how it turns out and if it helps

RickyNelson 09-26-2020 12:03 AM

Following...

Thank you!

BryonJ 09-26-2020 08:19 AM

Towel rack is at the beginning of the loop. Bedroom is at the end.

Quote:

Originally Posted by BigSxyWhtGuy (Post 2414123)
The 30 has the same towel bar.

Your alde system is under your dinette as is mine, are you sure your flow goes to the rear of the trailer first or does it flow the opposite direction? Iím not certain of that fact.

I believe mine goes in an anti clockwise flow but now that it is brought up, Iím not certain. In your case it matters as it changes the theory. If the towel bar is hot at the end of the loop then your challenge isnít with the towel bar but with something else.


BryonJ 09-26-2020 08:22 AM

Just seems the most logical at this point. Iím not an engineer but did do a lot of work with heat transfer when forming and quenching hot metal. We learned that surface area and contact were more important than temperature and flow rates.

Will be camping in two weeks in the mountains of east TN. I expect temps below freezing, so it the insulation test will get a good tryout.

Quote:

Originally Posted by BigSxyWhtGuy (Post 2414588)
Cool, sounds like your mind is set on bypass or insulation. Good luck, let everyone know how it turns out and if it helps



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