Owb heat exchanger trouble help please

[twinstaxx]

I have a owb I built. Hooked it up in my shop (well just slapped together in a hurry because I needed heat and didn't have enough time. I am sure you know what I mean.) It was working OK not perfect and now performance is falling off.
Here is a little rundown of what I got
Boiler is 50' away from coil or a little less
Has an old air handler laying down on the floor with a radiator out of a 02 Corvette for heat exchanger
Heat exchanger mouted at about a 45* angle hot water in the top cold out the bottom (radiator mounted sideways)
Was getting 130 air out temp with about 140* water and shop temp at about 50-55 with a high fan speed
Bell and gosset pump running 27/7
Shop is big and drafty

This is what it is doing.
The heat exchange will not keep a consistent temp. I will be working and will notice that it will feel cooler. So I will put my hand on the heat exchanger and it won't be that warm and also have cool spots. My top inlet hose is about 15" of radiator hose.
I can give it couple squeezes and in Les that a minute it the heat exchanger will be hot all over. Sometimes if I wait a bit with my hand on it I can feel the heat come and go but I will have instant heat if I squeeze the hose.

It's almost like the water is not circulating and when I sqeeze the hose it primes the pump back up for a little bit.
Also the pump is next to the heat exchanger and I am using the radiator drain to bleed air. It is at the top of the only rise after It it leaves the boiler.

P.s. sorry if this doesn't make good sense I usually have my wife look over stuff for me and she is asleep

 

[JCMC]

It sound like the radiator hose maybe collapsing on the inside. I would try replacing it and see if that helps. I had this happen on a vehicle once and spent a lot of time trying to figure it out. Hope this helps!

 

[lindnova]

Sounds like air in the system. Picture of setup?

 

[cantoo]

Try to eliminate the rad hose by using muffler pipe and a couple of Fernco's? Is there any way to remove the return line to the OWB and see if you have good water flow? Maybe disconnect it and run a cheater pipe to your OWB overflow and pump the water back in there?

 

[diezelsmoke]

I would have the inlet hose come in at the bottom of the radiator. Is the pump above or below the grade level of the OWB?

 

[lefturnfreek]

It sounds like the pumps is quitting pumping or is getting air locked as that sounds like it should work fine. There shouldn't be enough flow from that pump to suck the rad hose closed unless your building vacuum in the system lines, which would prove something has gone catawampuss on you.

 

[Andy-H]

you have air pockets in your system, that is why the heat is inconsistent. Run hot in the bottom of heat exchanger and have a way to vent trapped air at the highest point in your system

 

[NSMaple1]

What is the vertical relationship of the OWB to the heat exchanger?

 

[twinstaxx]

Sorry covered up busy
The hose can't suck shut they are after the pump. The pump is lower or about even with the bottom of the boiler. The thing is so rigged and threw together I hate to even take pics.
I use the drain on the radiator to bleed the air. It is at the top of the radiatornand because it isn't mounted solid I even moved it around to try to get more air out. I haven't gotten any air our senses the problem has started.
If it is air idk how it would have gotten in there it was working OK.
I am leaning towards it not pumping or other is trash blocking flow.
Top hose comes out of the top boiler towards the ground and gose in the shop and runsin my shop on the floor next to the wall. The cold side does the same but gose in the very bottom. The only places the hose isn't flat is at the boiler and at the radiator (that I can bleed the air out of.
It sat with the top open for a long time after I built it and before I hooked it up. I think it had something in it when I filled it up. Worst part is no water at the shop so i can't drain and refill it until I get my forklift back up and running.

Thank you for your help guys

 

[twinstaxx]

The pump is on the floor of the shop about even with the bottom of the boiler and the heat exchanger is on the floor on the outlet and about 14"above the floor to the inlet.

 

[diezelsmoke]

Your problem then is your inlet to the radiator needs to come in from the bottom and exit out the top back to the OWB.

 

[twinstaxx]

I see most people are running theres like that. What is the theory or science behind in the bottom and out the top. It just goes against what I've been taught. Heat rises and cold falles so gravity would kinda help flow.

 

[JCMC]

If you have a taco pump you might want to check the impeller inside the pump as they deteriorate. I have seen 2 of these pumps that it happened to.

 

[diezelsmoke]

I see most people are running theres like that. What is the theory or science behind in the bottom and out the top. It just goes against what I've been taught. Heat rises and cold falles so gravity would kinda help flow.

If I fills from the bottom up no chance for air to infiltrate the radiator will work more efficient (same theory as hyd cooler plumbing). Remember as you heat water over 150F your water gives up the dissolved air that is naturally in it, so until you work through that process you will have air within your system.

 

[NSMaple1]

Sounds like there are high spots air could get trapped in. Without pics, can't offer much more....

 

[twinstaxx]

The hose is flat on a concrete floor. The only spot thet is Any rise is at the boiler and the heat exchanger.

 

[stevetheboatguy]

I have to ask.

Is it possible that your fan is moving more air than the radiator can handle?

I have a similar setup in my garage ('72 chevy truck rad) and in my shed (nisan car rad). I noticed I get much better performance from them. If I slow the fan speed down.

I don't know if your rad is a 2-3 or 4 core, but the two core do not work well at all. The three and four work just fine. Copper and brass are much more even heat transfer. The aluminum and plastic radiators are not so good. Fine in your car but not what we use them for.

I went cheap on the garage and shed, I bought a factory unit for my house. It looks better and was easier to mount above my furnace. But it doesn't work any better than the car and truck radiators. I had to slow the blower down a little bit on that too. Much better heat transfer doing that.


Steven

 

[twinstaxx]

The fan seed is Hi but the shop is so drafty it has to be.
It has to be a flow problem because it doesn't do it constantly. It comes and goes. As soon as I squeeze on the holes a couple pumps everything gets hot almost immediately. The steel nipple coming off of the pump even gets hotter when I squeeze the hose. I think there has to be some kind of blockage in there as soon as I get the parts for the forklift so I can fill it up with water I will drain it and see if I can get it cleaned out. Thanks for your guy's help I'll let you know if I figure something out

 

[twinstaxx]

If I get a chance and can remember how to post a picture I'll try to get one. I has been a while since I posted a pic on a forum.

 

[twinstaxx]

Looks like the radiator is all stopped up