Hurricane-hot heater question

[ChurchBuz]

Hello all:

I have a hurri-hot in the back with a mile of 1” hose in the way of my floor insulation and install.

I am not worried about getting it out of the way for the floor install if I need to keep it, I can do that. But I have a few questions.

Do I need that giant rear heater, my floor will be insulated, and my area will be halved to about 15’ instead of 30’? Will the heaters up front come close to keeping up?

The lines to the heater are 1” with a pump. I have a smaller heater with a fan, but it is 1/2”. Can I neck it down and use the small heater in the 1” circuit?

Can I use the pump in that necked down system?

Do I need to worry about introducing air pockets into the system?

Thank you in advance. I really respect y’all’s experience.

Philip

[cadillackid]

Originally Posted by ChurchBuz

Hello all:

I have a hurri-hot in the back with a mile of 1” hose in the way of my floor insulation and install.

I am not worried about getting it out of the way for the floor install if I need to keep it, I can do that. But I have a few questions.

Do I need that giant rear heater, my floor will be insulated, and my area will be halved to about 15’ instead of 30’? Will the heaters up front come close to keeping up?

The lines to the heater are 1” with a pump. I have a smaller heater with a fan, but it is 1/2”. Can I neck it down and use the small heater in the 1” circuit?

Can I use the pump in that necked down system?

Do I need to worry about introducing air pockets into the system?

Thank you in advance. I really respect y’all’s experience.

Philip

I got rid of my rear heaters and replaced them with much better quality units.. Bus heaters are designed to fit under seats or tuck back on walls and be bullet-proof when kids kick them.. I am using Jegs heaters in the rear.. and my Mid-heater is part of my mid A/C..



I kept the 1 inch trunk lines and they get necked down to 5/8" in the rear, with the jegs heater..

**BUT** im running a parallel flow system.. if your system is like most bluebirds, the heaters are all in series.. so that 1 inch line is needed and the pump to keep flow fast enough that the last heater in the system doesnt get cold water..



with parallel flow you WANT the last unit to neck down so it creates pressure in the trunk for flow.. the head pressure of that pump isnt that high if its a bergstrom like most are and running it will help you make sure all the heaters have warm coolant.. but I wouldnt nec down on a series system any more than 5/8 bare minimum and 3/4 preferred.. I would keep the 1 inch until you are sending flow to the last heater...


in my conventional bluebird the flow is

engine --> right front --> driver --> Boost pump --> webasto --> rear --> engine..


I kept the 1 inch lines all the way in that bus as its stock bluebird..



if you stop it down to 1/2 you will need that pump for sure esp in real cold weather... thats smaller than any heater ive ever seen unless its a wimpy heater.. most are 5/8..

[ChurchBuz]

Great info!

Pardon my ignorance. I called my lines 1/2”, but that is the ID. The OD is actually 5/8”

I’m not sure what to call what I have.

In residential plumbing, 1/2” copper or pex is called by the ID.

[ChurchBuz]

If it is measured by the size of the rubber hose, or the OD of the fittings, then I have a standard aftermarket automotive heater with 5/8” fittings.

SO it sounds like I can use it.

[magnakansas]

I abhor not being comfortable when I can be comfortable. I have not only kept my rear heater, I swapped it for one almost double the size….. I have not tried it yet, but it might be large enough to use as a radiant heater with no fans. Cold mornings, the bus, the engine and windshields should be ready to go before I ever step out the door.

If you want a smaller package with quieter fans, please, for the love of all that is right in the world, PAY ATTENTION to what Cadillac kid says works. He has had years of experience and is very good at analysis of systems. If he says it works better, it does work better.

Cadillac knows more than most us and I have never known him to be incorrect.

William

[cadillackid]

Originally Posted by ChurchBuz

Great info!

Pardon my ignorance. I called my lines 1/2”, but that is the ID. The OD is actually 5/8”

I’m not sure what to call what I have.

In residential plumbing, 1/2” copper or pex is called by the ID.

plumbing and lines are somewhat Voodoo.. never understood why the various methods of measurement,



in home plumbing its as you say "ID".. in refrigeration its "OD".. im guessing it has to do with the thickness of the pipe..



anyway in the automotive world where hoses fit over fittings.. the hard line (fitting) is typically measured in OD while the hose itself is ID.. if you think about it, the hose must fit over the hardline fitting... if standard 1/16" wall pipe is used then you have 1/2" ID on the heater itself as you use up 1/16 X2 when measuring across a pipe's interior..



to make that piece work.. youll get some 1" to 5/8 reducers.. where you put the reducers are up to you.. but if it were mine id leave the 1" hose in place if it hasnt been damaged in your demo of the bus... the trick is CONTINUOUS run.. dont splice your house in areas you cant EASILY get to...



I pulled 43 year old hose out of my 1978 Superior (built in 77)... it was still in most excellent shape in the chaseway.. and guess what it went right back in when I was done doing what I needed to around that chaseway..


I use the Jegs Ductable 40,000 BTU heaters in my DEV bus.. they move lots of air and lots of heat.. and you can conceal them(duct the outlets where you want and duct in a return air)also (remember anything with a joint or clamp you need to have access as it WILL leak sometime in its life)..

[ChurchBuz]

Originally Posted by cadillackid

plumbing and lines are somewhat Voodoo.. never understood why the various methods of measurement,



in home plumbing its as you say "ID".. in refrigeration its "OD".. im guessing it has to do with the thickness.

Yep! Or it started with the first person who measured the first critical part for what they were doing. lol



I pulled 43 year old hose out of my 1978 Superior (built in 77)….


I use the Jegs Ductable 40,000 BTU heaters ….

Yes, I am right there with you. I will need to check the BTU’s on the heater I have. I will shoot for 40,k

I absolutely plan on reusing the 1” hose, it is in great shape. Though it has been spliced in places,

I already made some reducers out of 1/4” wall 1/2 ID aluminum. They are far from CNC, but they will do the job. I will post pictures if I remember before I get excited and assemble them inside the hose.

Thank you so much again for sharing your knowledge.

[ChurchBuz]

It looks now as if I will be putting in a hydraunic heated floor.

I bought a diesel water heater, and am considering installing it in the coolant system to warm the engine, but also valving it off to heat exchangers.

One for domestic water heating, and the other for low temperature use in the floor.

It seems that it should not be too hard to have that low temperature system regulated with thermostat/ valve to also be connected to the engine heat, especially since the diesel heater will already be tying the two systems together.

Having the floor around 90 degrees, sure would make/keep things nice and comfortable while driving

…. and require fewer btu’s in my extra heater.

[ChurchBuz]

Here are the reducers. Pretty simple.

[ChurchBuz]

CK: I ordered the 40k heater, and made 1 to 3/4” reducers.

Thanks again!

My heater I had was like 12k.

[cadillackid]

hydronic floors are really nice!! how do you plan to do them? closed loop with a bleed-in of hot coolant? (pump circulating the 90f coolant around and a bleeder valve to introduce hot coolant when you need some more heat?) or run a water-to-water heat exhanger where the floors have their own expander tank and get warmed by the heat exhanger which valves off the hot side when the loop is warm?..


ive only done hydronic floors in a house never a bus.. somewhereinusa has a really nice hydronic floor setup in his, hopefully he pops in here...


Love your reducers those should work like a champ!!


I have my DEV bus set-up where I use the bus coolant system as my expansion system for my interior coolant.. in summer both electric valves get turned off when im driving.. in winter if i want to shut off the engine from being heated, I close ONE valve.. (I leave the return open).. since my system is parallel I can circulate coolant through the heaters and not the engine.. the one valve open allows for expansion / contraction.. that valve stays open even at night so as the systems cool down they dont collapse the lines.. they will pull in coolant to make up as it contracts...


that diesel heater has a thermostat where I can set it from like 30C up to 75C.. really coild days I run it flat out and it took a while but kept my bus nice N warm in 0 to -5F cold (warming it up from a bus that sat overnight)..



mild days I set it down in the 30s or 40s and with a fan on low it can make a nice soft heat... its a D&E 16kw coolant heater.. I had issues with the first one but they sent me a new one in early 2021 and I didnt have any issues out of that one over the winter.. in fact it started right up even though it was -20f one morning in minneapolis..



I used it to warm my no-glow-plug DT360 engine as it wouldnt have stood a chance otherwise..



one thing NEVER to do is use the interior heat and then open the valves to the engine while the interior heat is Hot.. you could crack your block or heads...

[ChurchBuz]

Again, great info.

Love the idea of using the engine coolant system as an expansion tank! After all, the factory built that feature into the system, why not utilize it?!

And I love: “don’t ever”s because they are usually overcomable.

And in the case of opening hot water from the heater into a freezing iron block is absolutely a no-no, but might have figured that out too late.

So in the case of having hot water in the system while parked, but needing to start the engine…

My thought would be that 90F degree water (from the floor) would not have nearly the disastrous effect that 170+ degree would. Especially at the low volume and speed as circulated through the floor.

3/8” or 1/2” pex in the floor is low volume compared to the 1” heater lines. If tapped into a 1” line both the volume will mix with the cold coolant in the line already, and slow down to fill the larger diameter.

In my head, it might take a long time to heat the engine, but it sure would be less of a shock.

Thoughts?

[cadillackid]

heres how I do mine..



if ive already been driving within the last few hours the engine is likely still warm enough (and a tad bit of coolant does bleed through the valves when wonder pump pressure(since it is backward pressure against them).. I usually turn off my diesel heater let the water cool down some then start the engine and let it run a couple minutes (till its often warmer than what the diesel heater is) then open the valves...


if I havent driven it and i need the diesel heater to warm the engine (Rare that I started the diesel heater and didnt already want it to warm the engine).. then id simply shut it off and leave my pumps and heater fans on till the water got down in the 100f or below range then open the valves and turn the heater back on.. 100f water is going to mix as it goes into the engine since ive got a parallel flow it wont go blasting in..

[ChurchBuz]

I just got my 40k BTU heater from Jeggs.

I called them and asked them about the supply line size and they told me 3/4”.

I made adapters, went out and bought hardware, but…

It is 5/8”. The 3/4” hose I have barely touches it, and that is because it is not perfectly round.

Bummer. At least I already made the 1 to 5/8 reducers.

Hopefully I can take back the brass T, cap, and elbow

Might have destroyed the wrapping.

[cadillackid]

Originally Posted by ChurchBuz

I just got my 40k BTU heater from Jeggs.

I called them and asked them about the supply line size and they told me 3/4”.

I made adapters, went out and bought hardware, but…

It is 5/8”. The 3/4” hose I have barely touches it, and that is because it is not perfectly round.

Bummer. At least I already made the 1 to 5/8 reducers.

Hopefully I can take back the brass T, cap, and elbow

Might have destroyed the wrapping.

yeah its 5/8... I thought it even said 5/8 in the jegs web, but maybe not..



the flow direction DOES matter .. the inlet should be marked so make sure you flow it the correct way

[Jolly Roger bus 223]

any coil should be marked and have the entering water into the coil on the leaving air side.
some are not marked.

[ChurchBuz]

Originally Posted by Jolly Roger bus 223

any coil should be marked and have the entering water into the coil on the leaving air side.
some are not marked.

This one is marked!

The question is…. Which hose is the inlet?

I sure hope that it is the one with the pump. That would make it a lot easier!

If that is not reliable, I can trace it to its source.

One goes to a heat exchanger at the bottom of the radiator.

The other comes out of the heat exchanger in the dash that is fed by the cylinder head. My guess is this connects to the inlet.

[ChurchBuz]

I just traced it.

The pump is inline on the inlet side. It comes from the cylinder head side.

I sure do appreciate y’all’s support. I understand just enough of this stuff to get myself in trouble. So I am glad that you check up on me to keep me inline.

Let me know if anything is amiss.

[cadillackid]

the pump pumps in one direction.. if you look at a pump they often have an arrow with flow direction.. .. also if a pump is the type where you have a motor spinning an impeller typically the inlet of the pump looks like it goes in the "shaft" opposite the motor.. and the outlet looks like it is on the outside of a turbine / wheel..



https://www.tacbusparts.com/BGP-S-Be...-Pump-Straight


in that picture.. the outlet is at the top pointing left, the inlet is lower and to the right..



that pic is a standard bergstrom pump used in many school bus heater pump applications..

[ChurchBuz]

I have mounted it vertically.

I sure hope that is alright.

Sideways pic. Mounted behind drivers seat.