Missy Conversion - 1998 MCI 102

[Brewerbob]

Originally Posted by alpine44

If you put a marine water-to-water heat exchanger (HE) in your engine coolant loop,

I need one of these for my tranny. The OEM one uses coolant to warm the transmission fluid and it's leaking. Blue Bird wants $600 for the exchanger and more than $100 for two 1" elbows. That so is not going to happen.

[JDOnTheGo]

Originally Posted by Brewerbob

A 1000 miles of tubing only has two leak points in my book. It's the fittings that are going to leak.

You are an optimist!! A real advantage!

[alpine44]

Originally Posted by Brewerbob

I need one of these for my tranny. The OEM one uses coolant to warm the transmission fluid and it's leaking. Blue Bird wants $600 for the exchanger and more than $100 for two 1" elbows. That so is not going to happen.

Sendure is a well known OEM.

Most marine gearboxes are cooled through a heat exchanger, either by coolant or sea-water.

[Brewerbob]

Originally Posted by JDOnTheGo

You are an optimist!! A real advantage!

You don't know me very well then. I've been accused (rightfully so) of many things. Optimist is not among them.

If you're worried about a pipe/hose bursting then you're in big trouble. Even if a 6" hose is less likely than a 6' hose to burst, the risk certainly isn't linear with length.

Come to think about it, I don't know that ... wait, the little 2 inch hose on the genny. It leaked thru the hose. But that hose was no less than 6 yrs old. Or it came with the genny which would make it 15 yrs old. The piece of hose on the other side of the filter is still decent so that makes me think this one was OEM. I replaced one sidewhen I replaced the filter in 2012 when it was last used. In either case, plenty of time to dry rot.

I don't think I've had any automotive hose other than that burst/leak except at fittings or where it has been rubbed.

Garden hoses, sure. They are in the sun and freeze in the winter. If you are plumbing your bus with garden hose, you wouldn't be here. Darwin would have found you by now.

[PNW_Steve]

Here are some heat exchangers that appear to be suitable for potable water.

I may have to put one of those inline before my propane water heater to preheat the water when my Webasto or engine are running.

Edit: https://www.brazetek.com/3-x-8-inch-...ngers-chillers

Oldztimers setting in...

[Brewerbob]

Originally Posted by alpine44

Sendure is a well known OEM.

Most marine gearboxes are cooled through a heat exchanger, either by coolant or sea-water.

Thx.

If it's stout enough for seawater and/or coolant then it ought to be able to handle coolant and tranny fluid. And I was reading thru the Blue Bird manual. Apparently I can use tranny fluid or plain old Jane 10w40 oil. If/when I do a tranny flush, I'll replace it with whatever is cheaper in the 5 gallon bucket.

[Brewerbob]

Originally Posted by PNW_Steve

Here are some heat exchangers that appear to be suitable for potable water.

Where is "here"? Looks like you forgot the link. Being an old person I don't think it too un-PC to say I hate them. The number of times I've put down a screwdriver and then spent literally 5 minutes looking for it when it was only 30 seconds ago that I put it down. I guess it's good exercise walking around to find it only 3 feet from where I was originally standing. Doesn't help the build time tho.

[Brewerbob]

Originally Posted by alpine44

Sendure is a well known OEM.

P.S. Sen-Dure if anyone else is looking.
P.S.S. Tried uploading the catalog but it's 6Mb; limit is 2Mb.

[JDOnTheGo]

Originally Posted by Brewerbob

If you're worried about a pipe/hose bursting then you're in big trouble. Even if a 6" hose is less likely than a 6' hose to burst, the risk certainly isn't linear with length.

I thought we were talking about in-floor radiant heat - I was at least. I have no facts on which to base my opinion/concern. Regardless; what I see a hundred feet (??) of plastic tubing buried "in" the floor with lots of "rub" points. When the coach is cruising down the road, all of those little points are rubbing. When a leak does occur, I see it being very small and unnoticed. Then, after a year, the entire floor (multiple layers of plywood plus laminate/carpet) all being coolant soaked and ruined. Then I see me having to remove EVERYTHING in the coach (cabinets, walls, furniture, refrigerator, etc.) to pull out every bit of flooring just so I can start over again. That is a terrifying thought so I would like to avoid it. For my pee brain, avoiding this scenario is accomplished by not installing in-floor radiant heat. Don't get me wrong - I LOVE it! In a S&B house, I bet it never leaks - maybe not even in the motorhomes that have it. Regardless, I'm not willing to take the risk in my coach - especially with me as the installer.

[Brewerbob]

Originally Posted by JDOnTheGo

I thought we were talking about in-floor radiant heat - I was at least.

I was leaving it be when you mentioned the leaks in regards to in-floor. I've no idea how flexible pex or whatever else can be used is but I'm betting you'd need more than two clamps to criss-cross the floor properly.

That said, the diesel water heater is going to have fittings too. That's why I was wondering why have both air and water if you are paranoid of leaks. Get a big enough air system and skip the water altogether.

I have no facts on which to base my opinion/concern. Regardless; what I see a hundred feet (??) of plastic tubing buried "in" the floor with lots of "rub" points. When the coach is cruising down the road, all of those little points are rubbing. When a leak does occur, I see it being very small and unnoticed. Then, after a year, the entire floor (multiple layers of plywood plus laminate/carpet) all being coolant soaked and ruined. Then I see me having to remove EVERYTHING in the coach (cabinets, walls, furniture, refrigerator, etc.) to pull out every bit of flooring just so I can start over again. That is a terrifying thought so I would like to avoid it. For my pee brain, avoiding this scenario is accomplished by not installing in-floor radiant heat. Don't get me wrong - I LOVE it! In a S&B house, I bet it never leaks - maybe not even in the motorhomes that have it. Regardless, I'm not willing to take the risk in my coach - especially with me as the installer.

I really like the idea of in-floor heat too. Again, I don't know anything about them. What I need to know is 1) tubing type (is it pex?) and 2) diameter of tubing needed. If you can go as small as 1/2" I might have a solution that works for me.

Spray foam the floor 1" thick, pex piping, then spray foam another inch. Or first spray is 1 ~ 1 1/2" thick and the second is just covering the pex. Numbers would vary based on the minimum tubing diameter. This way the tubing isn't rubbing on ANYTHING. The only thing exposed to vibration would be entry/exit to the foam. And if it leaks inside the foam, where's it going to go? The closed cell foam would keep it from leaking. This assume the foam is good to X psi and that the in-floor system runs below that. I can't see it being more than single digits. Probably only 3~5 psi?

Since your bus is "built" already you couldn't do this easily.

Any glaring holes in my theory?

[alpine44]

Originally Posted by Brewerbob

...I really like the idea of in-floor heat too. Again, I don't know anything about them. What I need to know is 1) tubing type (is it pex?) and 2) diameter of tubing needed. If you can go as small as 1/2" I might have a solution that works for me...

Tubing for hydronic floor heat is 1/2" oxygen barrier (not the regular drinking water type) PEX.

[Brewerbob]

Originally Posted by alpine44

Tubing for hydronic floor heat is 1/2"

Thx!!

oxygen barrier(not the regular drinking water type) PEX.

What does that mean and why not regular?

[alpine44]

Originally Posted by Brewerbob

Thx!!


What does that mean and why not regular?

Here we go.

The oxygen barrier protects ferrous components in a domestic heating system from corrosion. In an RV you can probably use non-corroding pumps, etc.

I have never used PEX-AL-PEX but that sounds easier to install than the barrier or regular stuff that has a mind of its own where it wants to lay.

[Brewerbob]

Originally Posted by alpine44's Link

Oxygen Barrier PEX overview

External coating of oxygen barrier PEX tubing effectively prevents diffusion of oxygen molecules into the water through walls of the pipe. This feature prevents corrosion of cast iron components in the system (circulator pumps, air purgers, fill valves, boiler heating elements, etc.).

I guess they don't care about faucets.

[Brewerbob]

Originally Posted by alpine44

.

What do you know about pressure and volume required? An aquarium pump might work if it's low enough. They last for yrs pumping salt water. At less than $100, they are fairly cheap.

[Brewerbob]

Found what I was looking for.

Originally Posted by website

For systems with the fill point at the bottom of the system, it may be necessary to calculate the required cold fill pressure. To do this, determine the height from the gauge used to measure system pressure, to the top of the system in feet. Note that it is the height from the gauge, and not the fill point itself unless they are at the same point. Divide this figure by 2.3 to get psi, and add 4-5 psi for the required minimum pressure at the top.For example, a system with a static height above the gauge of 40 feet will require a cold fill of (40/2.3) = 17.4 + 5 = 22 psig (see Figure 1). The fill device must then be adjusted to get that pressure on the gauge when the system is cold. If using a gauge at some point in the system where the pressure is affected by running the circulator, ensure that the circulator is off before checking the system pressure. Or, better yet, install a gauge at the fill point. Using the above calculation in reverse, the standard factory setting on fill devices of 12 psig would be adequate for a system with a static height of about 18 feet.

So, on a bus, 4-5 psi since the heater, gauge, fill point, etc. can be at the same level as the floor. A single foot off the floor for fill and air bubbles.

[joeblack5]

Alpine , do you have more info about your TEG generator/ webasto, I am only familiar with teledyne. I have build some 20 watt units with TEG modules but thatis all DIY.

[JDOnTheGo]

Originally Posted by Brewerbob

Any glaring holes in my theory?

Yes, sorry. The tubing has to laid in "gutters" with a sheet metal piece that transmits the heat from the tubing to the floor. If the tubing is buried in foam, the heat has nowhere to go. Regardless of how it goes in, it takes some space. Something that some coaches have and some do not.

Originally Posted by Brewerbob

Since your bus is "built" already you couldn't do this easily.

I made the choice NOT to go with radiant in-floor heat very early in the build. You are right, retrofitting would be even worse.

[JDOnTheGo]

Oh... that reminds me - going back nearly a year and a half.... To save headroom, I also considered installing the radiant heat UNDER the floor. Meaning, install it on the basement ceiling. This seems to be a common retrofit in the S&B world where the underside of the floor is accessible. They basically run the tubing between the joists under the floor. I decided that, for me, this approach was more complicated, more potential for leaks (although they would probably be seen (dripping coolant)), much of the ceiling is inaccessible (various parts and things mounted there), and would mean that I could not add much/any insulation to my floor.

One of the single most significant fears I had with this whole approach is the fact that I will occasionally mount something by running a screw thru the floor with a drill/driver. After doing so, I stop and wonder what I may have hit. I've been trying to change that style of operation for nearly my whole adult life, it hasn't happened yet... Sounded like a recipe for disaster...

And you wonder why I don't document the entire decision making process.... Since there are only about 50,000 decisions to be made, this thread would overwhelm the servers!

[Brewerbob]

Originally Posted by JDOnTheGo

Yes, sorry. The tubing has to laid in "gutters" with a sheet metal piece that transmits the heat from the tubing to the floor. If the tubing is buried in foam, the heat has nowhere to go.

Doesn't sound hard to do and could still be on the foam.

Regardless of how it goes in, it takes some space. Something that some coaches have and some do not.

Since I'm raising the roof 15", I have room to spare.