Hurricane-hot heater question

[cadillackid]

so you want to go from the Outlet of the pump to the inlet of the heater...



if the pump inlet is forward of where your heater will be.. ie rear engine bus and the engine pumps coolant first through the rear heater and then sends it forward into the booster pump.. then you would make the INLET of the rear heater be from the engine compartment.. and the OUTLET of the heater would go towards the inlet of the pump..



in a front engine Bluebird bus, coolant typically travels in the right side heater.. then into the driver heater. then out of the drivers heater and into the pump.. then out of the pump and into a MID heater (if equipped).. out of the mid heater and into the rear heater.. then a long line all the way back up front into the engine inlet..



your jegs heater inlet should be connected to the hose with the pressure.. ie coming from the pump.. the outlet of the rear heater would then be the return to front..



all the heater loops begin and end at the engine..

 

[ChurchBuz]

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-Bergstrom-Booster-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..

Wow! Spot on! Not that I am surprised : )

I had looked at my pump trying to find an arrow or something, did not even think that the center, port which would utilize centrifugal action, would be the inlet, but it makes perfect sense.

My pump is a groco. lol. Now that I read it, it says right on it, centrifugal pump.

lol.

Feeling pretty silly. lol

 

[ChurchBuz]

Do I need to be super careful about introducing air into the system, or will the pump push it all out?

I can fill the components with 50/50, but I am also trying not to spill a lot inside the bus.

 

[ChurchBuz]

Sun is about to set, so I am out until Sunday.

I will be sure to check for replies.

Thanks again!!!

 

[cadillackid]

you'll get air in the lines.. its inevitable.. theres often a bleeder valve or two on the heater main lines under the hood.. otherwise it does work its way out and ends up at the top of the system.

 

[cadillackid]

groco is another manufacturer.. there are quite a few actually who make booster pumps... the yall work similar.. centrigual style and are not self priming so coolant needs to be present or the pump will just spin ( and its hard on the seal).. but starting the engine and opening the heater valves will help with that..



be sure when you disconnect your heaters you close BOTH engine valves (and any inside valves you have at the driver console).. this will keep you from draining the whole system down to floor level.. you will still get quite a bit of fluid ..

 

[Jolly Roger bus 223]

the truth is the pump can be either supply or return. as long as it moves the water.
they do make air release valves which are great until they hang up and even though i deal with them daily i have been talking bus stuff and cant remeber the correct term.
now i feel like an idiot? gotta get off here and figure it out?

 

[Jolly Roger bus 223]

yes i had a brain fart.
automatic air vent.
can and will work for your system.
you could probably make one.
its nothing more then a ball that is held up by liquid pressure and once enough air gathers up the ball/BB drops to get rid of the air.
under the hood not an issue.
sorry i had work and bus stuff at the same time?
but yes a pump can go anywhere as long as it moves the fluid.
many engineers will debate that and some have put them in the wrong places.
now back to work stuff in my head? sorry.
i do water for a living.
a bus opinion is just an opinion?

 

[cadillackid]

yes i had a brain fart.
automatic air vent.
can and will work for your system.
you could probably make one.
its nothing more then a ball that is held up by liquid pressure and once enough air gathers up the ball/BB drops to get rid of the air.
under the hood not an issue.
sorry i had work and bus stuff at the same time?
but yes a pump can go anywhere as long as it moves the fluid.
many engineers will debate that and some have put them in the wrong places.
now back to work stuff in my head? sorry.
i do water for a living.
a bus opinion is just an opinion?

ive used automatic air bleeders in hydronic heating systems.. but those systems never go negative pressure like a bus coolant system does..



you figure in a home . commercial hydronic you either have an automatric water feeder maintaining a pressure (usually 10-12 PSI).. and then have an expansion tank that when good will be partially full exerting some pressure on the system as well..



in a bus when its cold the coolant system goes negative.. and i have to wonder if the automatic air bleeder would suck air in if the continuous water column is lost..

 

[cadillackid]

yes i had a brain fart.
automatic air vent.
can and will work for your system.
you could probably make one.
its nothing more then a ball that is held up by liquid pressure and once enough air gathers up the ball/BB drops to get rid of the air.
under the hood not an issue.
sorry i had work and bus stuff at the same time?
but yes a pump can go anywhere as long as it moves the fluid.
many engineers will debate that and some have put them in the wrong places.
now back to work stuff in my head? sorry.
i do water for a living.
a bus opinion is just an opinion?

pump placement is design dependent.. for instance in my bus, I valve off ONE of the valves going to the engine and leave the other open.. my heaters are 1 inch in parallel with my rear heater being biased so it restrcits partially the flow at the rear creating pressure differential for flow through other heaters.. in this case i have a booster pump that is Inside the main valves so coolant can circle around inside the bus without the engine involved.. the factory boost pump is under the hood on the engine side of the valves...



when driving you run the engine pump. when parked you run the inside pump (and the webasto)..

 

[Jolly Roger bus 223]

my idea was only my work and yes more closed loop system.
open loop stuff i have different parts.
maybe a manual vent valve to get the air out of the system might me better?
dont know its not mine?
and you are correct on negative systems but in my opinion why would a system go under negative pressure if it was properly maintained?
yes positive and negative on a pump but in a complete system with no leaks?
a coolant pump flow is a coolant pump flow.
yes the coolant pump is a branch from the motor/engine water pump and dash heat but it is auxiliary? now i am just rambling?
i dont want to mix someone up between building coils and bus coils.
i love my VAV boxes over VRF stuff mr. chris.
LG sucks and i like mitsubishi.

 

[Jolly Roger bus 223]

i think it would work on his system to get rid of the air better than guessing if you have an air pocket and having to open a manual valve?
there is a place and purpose for manual valves when you know what you are looking at just like pressure guages and P/T plugs.
but he can always pull and plug the air vent when he is comfortable with the lack of air in his system.
sorry work stuff in my head verse bus stuff?
but his catch can also has this purpose if he has one?
gotta quit taking a break from working and going to skoolie?
sorry ladies and gents.
sorry to the OP.

 

[somewhereinusa]

I'm getting here a little late and I just skimmed most of the posts. My hydronic has been working quite well for over 8 years. Here are some random thoughts.
My heat system uses an Espar Hydronic 12 which keeps the water temp in the main loop at 160° F. I have a manifold in the main loop with 4 branches for each of the 4 rooms. The thermostat in each room controls a pump in each loop. There is also a small heat exchanger with fan in each room.
The main loop has a plate type heat exchanger to warm the engine. I'm using a marine water heater with a built in heat exchanger also in the main loop. The water heater also has a 120VAC element for use in the summer. The whole system is built with a expansion tank, like an automotive cooling system, and uses a 15 psi automotive radiator cap.
There are three types of water separated by use of the heat exchanger. Engine cooling (poison), heating system (not poison) and domestic hot water. There would have to be failure in two heat exchangers for engine coolant to make it's way to the domestic hot water.
If the engine is running I have heat and domestic hot water,
If the boiler is on for heat I have domestic hot water and the engine is warm.
Some random thoughts.
I'm not sure 90° in the floor is warm enough.
Put in more bleeds than you think is necessary.
Make sure you have a pressure relief valve in the domestic hot water.
Engine water temp has been no problem in any of the PEX.
I see no reason to use valves to isolate the engine, it MIGHT make boiler fuel consumption higher but I wouldn't think it would be much.

 

[cadillackid]

my idea was only my work and yes more closed loop system.
open loop stuff i have different parts.
maybe a manual vent valve to get the air out of the system might me better?
dont know its not mine?
and you are correct on negative systems but in my opinion why would a system go under negative pressure if it was properly maintained?
yes positive and negative on a pump but in a complete system with no leaks?
a coolant pump flow is a coolant pump flow.
yes the coolant pump is a branch from the motor/engine water pump and dash heat but it is auxiliary? now i am just rambling?
i dont want to mix someone up between building coils and bus coils.
i love my VAV boxes over VRF stuff mr. chris.
LG sucks and i like mitsubishi.

Coolant systems go negative when the engine is off and the system gets cold.. in an automobile this is when the coolant in the recovery tank gets partially sucked back into the cooling system. Some busses have that capability but some will suck a bit of air back into the bottle (which lives at the top of the system ).. so you don’t want to suck air in an active part of the system.. the bottle is up high and not in a flow loop directly..

LG and most of the china stuff sucks. Although I’ve gotten 13 plus years out of china splits at home.. Ii did a ton of VAV stuff.. remember trane vari-cone?? Lol

For big VRV.. daikin.. for snalller stuff I like Fujitsu .. which as they die is what I’m switching my home systems over to.. Mitsubishi is great kit.. except their &&@@;: condensate pumps ..

 

[ChurchBuz]

I'm getting here a little late and I just skimmed most of the posts. My hydronic has been working quite well for over 8 years. Here are some random thoughts.
My heat system uses an Espar Hydronic 12 which keeps the water temp in the main loop at 160° F. I have a manifold in the main loop with 4 branches for each of the 4 rooms. The thermostat in each room controls a pump in each loop. There is also a small heat exchanger with fan in each room.
The main loop has a plate type heat exchanger to warm the engine. I'm using a marine water heater with a built in heat exchanger also in the main loop. The water heater also has a 120VAC element for use in the summer. The whole system is built with a expansion tank, like an automotive cooling system, and uses a 15 psi automotive radiator cap.
There are three types of water separated by use of the heat exchanger. Engine cooling (poison), heating system (not poison) and domestic hot water. There would have to be failure in two heat exchangers for engine coolant to make it's way to the domestic hot water.
If the engine is running I have heat and domestic hot water,
If the boiler is on for heat I have domestic hot water and the engine is warm.
Some random thoughts.
I'm not sure 90° in the floor is warm enough.
Put in more bleeds than you think is necessary.
Make sure you have a pressure relief valve in the domestic hot water.
Engine water temp has been no problem in any of the PEX.
I see no reason to use valves to isolate the engine, it MIGHT make boiler fuel consumption higher but I wouldn't think it would be much.

I am all ears.

Do you run 160 degree water through your floor?

Or do you run it through the heat exchanger first to knock it down a couple of notches before running it into the floor?

You guys are a wealth of information

 

[somewhereinusa]

When using the boiler water temp is about 160° when using the engine, temp is closer to 190°
The heat exchanger is almost the same temp on both sides.
Return water temp is only about 10° lower than inlet.

 

[cadillackid]

When using the boiler water temp is about 160° when using the engine, temp is closer to 190°
The heat exchanger is almost the same temp on both sides.
Return water temp is only about 10° lower than inlet.

that doesnt make for hot feet?


I never ran hydronic floors anything close to that.. 120 max and that was only if it was carpeted (yes people heated carpet floors) 100-105 max for hardwood.. some customers wanted 90 or less (just take the chill off vs space heat)..



for under-floor radiant heating (pipes in heat spreading reflector pans)we would run 130-140 on startup and then a sequencer would limit the temp down to 120 after the first 20-30 minutes.. in thos scenerios you had sub floor and mastic (tile) sometiomes levelling concrete to go through..


now snow melt on the other hand you just run as hot of fluid as you can get.. and as high volume as you can get.. as many pipe loops as you can get the concrete contractor to sign off on and still maintain strength.... that takes CRAZY amounts of energy.. because you need to melt AND DRY falling snow / freezing rain as fast as it hits..

 

[somewhereinusa]

that doesnt make for hot feet?

Not really, probably because my floor is 3/4" plywood and, I do go barefoot. I have aluminum H channel between the plywood sheets, they get a bit hot, only place that's a problem is the one where I put my feet sitting on the throne.

 

[cadillackid]

Oh i got it! your heat loops are under 3/4 ply.. yeah thats a similar insulating property to hardwood floors (without the expansion contraction problem) so higher temperatures make sense.. its also similar to when I would do radiant pans below a subfloor.. we had to run much hotter water for those..

 

[ChurchBuz]

I am doing a thin vinyl floor right on top of the foam.

Sounds like I will need to scrub off some heat.

I have an idea for a thermosiphoning coil and a tempering valve

Hopefully that would work.

I will be feeding it with the water run through the heaters,, that should knock it down a little, I could do a loop of pex around the perimeter of the inside of the bus right at the sheet metal. That should be the coolest part of the interior, and would warm the walls a little. Then run it into the floor.