Solar, is it worthwhile?

[TheLooks]

I have worked with radiant ceiling panels, radiant floor systems for bathrooms, and radiant under wooden floors as well as imbedded in concrete. They work the best, all of them, where you are not relying on them for your main heat and the temps are not extreme. So, middle of the country and a bit south. Heat loss studies and examinations of the building envelope are critical to making them work in more extreme climates.

 

[Underboss]

Ok! That was more useful!

However it comes down to intent, and the options available come back to hydronic! And yes I consulted a retired professional who did to their rig what I am considering for mine. He didn't consider doing the slides, and I don't have any!

How you are going to do hydronic radiant floor heat in an existing rv? Also why? Electric radiant floor heat is so much more an efficient install. Faster, easier and once installed no fear of an accidental leak. Whereas tubing can rub and break, all the manifold connections add to the possibility of leaks and the real estate required for both the tubing height, the routing of the tubing to the manifold and the heating source open up the chances of leaks exponentially.
You can do a typical rv with as many zones of electric radiant heat as you desire. That leads to better efficiency as you are not heating the bedroom floor during the day where with hydronic, additional zones create additional manifolds or diverters taking up more real estate and again adding more chances for leaking in a mobile vehicle.

 

[TheLooks]

I have to agree I don't like the idea of heated floor with water in a mobile vehicle. In fact, I don't like them at all from experience!

 

[Underboss]

I have worked with radiant ceiling panels, radiant floor systems for bathrooms, and radiant under wooden floors as well as imbedded in concrete. They work the best, all of them, where you are not relying on them for your main heat and the temps are not extreme. So, middle of the country and a bit south. Heat loss studies and examinations of the building envelope are critical to making them work in more extreme climates.

Again, you seem to be talking apples to oranges and I don't understand how you are conflating residential to an rv in an RV discussion.
Though, the 62 story building I did was residential and in NY City. These new electric systems are relatively efficient and offset the other utility costs.

 

[TheLooks]

Merely explaining I have worked with a variety of radiant systems. The OP was talking water, you changed it to electrical. I disagree with efficiency as a measure of how much they cost to operate. But NYC is another thing altogether. Not comparable to rural stand alone houses.

 

[Underboss]

Merely explaining I have worked with a variety of radiant systems. The OP was talking water, you changed it to electrical. I disagree with efficiency as a measure of how much they cost to operate. But NYC is another thing altogether. Not comparable to rural stand alone houses.

But again, we are discussing radiant floors in RVs.

 

[Kevin D Pem]

But again, we are discussing radiant floors in RVs. I was on topic. I am not sure why you seem to keep going back and discussing residential but I will bow out now because this discussion has clearly run its course

Yes efficiency is my goal! Sometimes it does a body good to see where a discussion comes from and where it's going.

From the get-go I brought up solar efficiency! So if we talk apples to whatever, we must understand where the design comes from and the intent.

The last such system I did like this, it relied on natural convection! This design will rely on a circulation pump, but will still be open to the atmosphere! As a supplemental system designed for the desert southwest, surely it may serve as a primary system, however, it will not be designed as such.

How that makes any sense is to consider my approach to life in general! Then one can almost see the logic, from another's eyes.

And to add to your "there can only be one way" view! Solar power and electrical heat stripes are not a good match! At one time RVs were conservative, but are now power hogs. My rectification with this blatant misuse of resources, can not take place within my very being!!! So it won't.

 

[RTRanger]

I love solar. I have put solar on all three RVs we’ve owned. Currently we have down sized to a Roadtrek Class B. Put 200w on the roof and 200ah LiFePo batteries. If parked in the sun the compressor fridge can run 24hrs and the batteries will be at 100% by noon. I use the Renogy DC-DC controller that will solar charge the vehicle battery when the house batteries are full. It also charges the house batteries after the vehicle battery is charged when the engine is running. Totally trouble free and everything is always fully charged. With the small loads in our little Class B we never need to plug into AC. (Unless we need AC.) It is worth it to me!

 

[Underboss]

Yes efficiency is my goal! Sometimes it does a body good to see where a discussion comes from and where it's going.

From the get-go I brought up solar efficiency! So if we talk apples to whatever, we must understand where the design comes from and the intent.

The last such system I did like this, it relied on natural convection! This design will rely on a circulation pump, but will still be open to the atmosphere! As a supplemental system designed for the desert southwest, surely it may serve as a primary system, however, it will not be designed as such.

How that makes any sense is to consider my approach to life in general! Then one can almost see the logic, from another's eyes.

And to add to your "there can only be one way" view! Solar power and electrical heat stripes are not a good match! At one time RVs were conservative, but are now power hogs. My rectification with this blatant misuse of resources, can not take place within my very being!!! So it won't.

If you have beliefs on a waste of resources thats fine. For instance I have put solar on three of my homes. Started around 2005. I do not put solar on my rv because I do not use it for boondocking and for the amount I do use it the cost is prohibitive.
As a builder and an rv owner for over 25 years, I stand by my "never in an rv" post for a wet floor heating system. You are doing it more on a principle basis and I can respect principles. I am just not sure how you will heat the water to a temperature that will heat then floors without using natural resources.
I am not sure of the pump usage of electricity but a 4' x 10' heat mat draws 3.9 amps.
You seem much more knowledgeable than me about electric usage, draw etc. How does that compare to a circulation pump? I have tried to search but most do not listed amp draw. I would imagine a 1/25 hp pump would be about 1 amp.

 

[Kevin D Pem]

If you have beliefs on a waste of resources thats fine. For instance I have put solar on three of my homes. Started around 2005. I do not put solar on my rv because I do not use it for boondocking and for the amount I do use it the cost is prohibitive.
As a builder and an rv owner for over 25 years, I stand by my "never in an rv" post for a wet floor heating system. You are doing it more on a principle basis and I can respect principles. I am just not sure how you will heat the water to a temperature that will heat then floors without using natural resources.
I am not sure of the pump usage of electricity but a 4' x 10' heat mat draws 3.9 amps.
You seem much more knowledgeable than me about electric usage, draw etc. How does that compare to a circulation pump? I have tried to search but most do not listed amp draw. I would imagine a 1/25 hp pump would be about 1 amp.

In order to keep things apples to . . . We must convert everything to watts. So .00134 hp = 1 watt, this doesn't take losses in account. That makes 1 hp = 746 watts rounded up. Keeping things to your history! BTU/h = watts * 3.412141633 .
This is where the truth gets sticky!
3.9 amps at what voltage? At 12 volts would be 46 watts or 13 btu/hrs. At 120 volts 468 watts or 137 btu/hrs. or 220 volts 858 watts or 251 btu/hrs. So we must consider what values we are discussing here.

The efficiency of pv is still well under 25% ,the efficiency of heat collectors is better than 50%.

A 250 watt pv is roughly 1.5 meters sq, and to collect 750 watts of heat the same size panel is used. Or roughly 219 btu/hr. In my circumstances I have roughly 3.5 meters not usable for pv but great for collecting heat. That gives me over 400 btu/hrs of heat to disperse within my RV! will it keep me toasty? I don't think so! Will it make me more comfortable? Most definitely!

Will I find the folly in my design? No! Because your argument has been on the back of my mind sense it's conception.

What I know is the disparity between the two technologies at my disposal, clearly gives me a direction!!!

 

[MemoriesByTheMile]

Ahh hah - I must have missed it earlier. You are considering using the sun to heat the hydronic system. I assumed (incorrectly) you were using solar electric panels, storing the electric, then using that electric to heat.
From an efficiency perspective, totally agree that using solar heat collectors vs solar electric collectors is more efficient.
Still not sure that hydronic would be a good idea, high risk of leaks over time and lost space.

 

[TheLooks]

Welcome to a discussion, any discussion, with Kevin D Pem Mr. Underboss.

 

[Kevin D Pem]

Ahh hah - I must have missed it earlier. You are considering using the sun to heat the hydronic system. I assumed (incorrectly) you were using solar electric panels, storing the electric, then using that electric to heat.
From an efficiency perspective, totally agree that using solar heat collectors vs solar electric collectors is more efficient.
Still not sure that hydronic would be a good idea, high risk of leaks over time and lost space.

So I'll spill the beans!

This revival came about because I want my porch/greenhouse heated to avoid freezing(heated beds).

Water because, a leak is easier to clean up than oils would be!

The mass can be dumped for travel, though the original design used phase changing materials to save space!

Because comfort can be increased, my plan is a dry radiant installation, in the form of mats on the floor to heat my feet where I spend my time while indoors. As I write this the thermometer tells me it's 56 degrees, and I am fine with that, and the heater is off, that's what jackets are for.

With the PV I have, I have more comfort than many people I know and I do that without choking on generator fumes.

For the most part I travel for comfort, and find I burn less resources than those that stay put and try to make their environment liveable!!

All in all, I live considering my impact on mother earth. This requires me, to make sure promises of earth friendly, are not smoke and mirrors.

And don't worry about water damage, because everything will be visible for inspection!

 

[TheLooks]

I will be sure and burn extra to make up for you.

 

[gfmucci]

I'm mulling a travel trailer towed by a Ford f150 hybrid that has a built in generator/lithium ion battery to run AC overnight when needed, plus the 200 watt panels that come standard with many TTs for trickle charging the house batteries.