Bus Coolant Heater System...

[mqbus767]

Hello Busnuts,

I'm seeking any comments/advice/feedback on my plans to install a coolant loop and cab heaters in my bus conversion. I've removed the factory heater but still have the coolant loop, capped off by a pair of ball valves, in the evaporator bay. My plan is to run 5/8" heater hose from the coolant ball valves through the interior of the bus and install 4 or more cab heaters similar in style to this one:

https://www.amazon.com/13-000-BTU-Universal-Auxiliary/dp/B07MLSK8Y8/

I'll run the heaters in parallel with additional ball valves on each heater to control/shut-off flow to each of them.

I will also be installing a diesel parking heater to heat the loop when stationary similar to this one:

https://tenzuatp.en.made-in-china.com/product/NsXmvQrxniWZ/China-Water-Parking-Heater-Diesel-Fueled-Engine-Coolant-Heater.html

So a few questions:

* Has anyone do something similar to this? If so, any pitfalls/caveats I should be aware of?
* The diesel parking heater has a pump built into it. It was intended to circulate the engine coolant and the bus heater core to pre-heat the engine and warm the interior. Any concerns about adding 100' or so of 5/8 coolant line to the loop and the pump not being able to handle it?
* I'm unsure of the direction of the flow of the coolant (supply vs. return) I'm sure I can figure it out easily. I'm assuming it doesn't really matter which way I hookup the loop to the heaters. Flow is flow, right?
* Other than some more ball valves to control the flow to individual heaters, I'm thinking I don't really need any other hardware. Check valves shouldn't be necessary. What about a way to bleed the system? Expansion tank?

My general thinking is this is really no different than cutting up the original heater core and spreading it out all over the bus. Please correct me if I'm wrong.

Thanks guys!

[lvmci]

Do you still have the heater above the steps?...

[mqbus767]

Yes. the heater at the front of the bus is still intact and functional.

[mqbus767]

Here's a picture of the evaporator bay with the coolant pipes highlighted:

[HB of CJ]

Might consider increasing the hot hose to 3/4 inch diameter, plus PERHAPS another in-line booster pump at the tail end of the run.  Engineer it soss the hose slightly drops along the run and place a drain valve at the low point, along with a vent valve for draining the system totally.  Remember the hose may reach high temps.

[lvmci]

Have you looked into increasing the fan size to heat more of the front stairs heater to accomplish your heating needs? lvmci..

[mqbus767]

Interesting idea that I had not considered. That would certainly save time/money. I could also consider plumbing the front set of heaters via the front heater and the rear via the evaporator connections.

I'm really interested in having fine control over the distribution which several smaller cab heaters would give me. My biggest running concern is the fan noise from these units. In the cab of a John Deere on a farm, the motor noise is probably negligible, but trying to sleeping in a bunk on a cold winter night with the unit a few feet away may be uncomfortable.

I also like the idea of using one heater in the wet bay itself to keep things from freezing.

I appreciate you guys helping me bounce ideas around.

[luvrbus]

The DL3 has a diesel fired system in the rear for heating does it work ?

[sledhead]

what about something like this as it uses  computer fans and might be quieter

https://www.amazon.com/dp/B09JK1GRNZ/ref=sspa_dk_detail_0?pf_rd_p=d81b167d-1f9e-48b6-87d8-8aa5e473ea8c&pf_rd_r=NPFFMF1QJ9WKVQCVPFH8&pd_rd_wg=tN3Jb&pd_rd_w=G609p&content-id=amzn1.sym.d81b167d-1f9e-48b6-87d8-8aa5e473ea8c&pd_rd_r=eb3432ac-32d8-4563-a97c-69fe4882d7f5&s=automotive&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzMkFTQk9JR0FSOEVSJmVuY3J5cHRlZElkPUEwODkyMDMyM0Y5V1ZBUThIV1ZaWiZlbmNyeXB0ZWRBZElkPUEwMjk0NDMwQUk2QjVVNEFKTjBFJndpZGdldE5hbWU9c3BfZGV0YWlsX3RoZW1hdGljJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ&th=1

[chessie4905]

Red Dot sells heater units, parts and accessories, been around for years. Supplies commercial industry.

[Iceni John]

I think that 13K BTU heaters may not give out enough heat in cold weather.   My bus still has its original Bergstrom heaters, an 80K in the back and a 70K front/defroster, and in cold weather I have all 150K running!   School bus heaters are relatively cheap and work well, and can be bought from many school bus parts suppliers.   My bus has 1" pipes and hoses for the coolant supply and return lines, and a Bergstrom booster pump.

I have two air-only 5KW CDHs, and the one inside the bathroom that heats the bedroom makes hardly any noise on low to medium settings.   Its fan is so quiet that I can hear the pump ticking, but even that is quiet because it's mounted below the floor away from the bedroom.

John

[mqbus767]

luvrbus: There was no diesel parking heater in my DL3; Houston city bus. I've purchased a "30K" BTU diesel parking heater that's used for pre-heat and heating the interior coolant loop on tour buses so I'll have quite a bit of heat.

Iceni John: The plan is for multiple radiators (similar to the one that sledhead linked) distributred strategically through the interior.

sledhead: Yes, but need (desire) 24v. I've shopped around and there are quite a few options from Jegs to the Amazon Chinese flavor. I'll  probably wind up ordering a single cheap one from Amazon and assessing it's suitability for my application. I certainly don't want a bunch of coolant leaks in the bus.

lvmci: I'd like more fine grained control over the heat distribution rather than just pushing heat from front to back.

chessie4905: Was not aware of Red Dot. I'll check them out too. Thanks!

[sledhead]

my coach had a boiler system when I got it but I had lots of problems with it . so I made my own system and used some of the old parts from the old aqua hot boiler and installed the pro heat 4500 as the engine preheat , hotwater , coach heat with 6 muffin fan heaters + 2 of the same in the basement

works better then the old system and much faster

dave

[mqbus767]

Very nice! Thanks for the pictures and the inspiration.