DIY Hydronic pumps, valves, heat exchangers

luvrbus · December 03, 2019, 09:35:57 AM

You get very little flow from the pumps (March) when they are not running

Lee Bradley · December 03, 2019, 01:33:30 PM

That is true but have you tried pushing water through them when they're not running? Pumps on a manifold; one pump running will pull water from the manifold source and backwards (pump will have pull from the pump(s) on the manifold and push from the return side of the manifold) through any pump not running. All of my pumps pump through a check-valve into their circuit. Two into floor sectors, four into toe-kick heaters and one into a ducted heater in my bus.

luvrbus · December 03, 2019, 02:27:30 PM

Quote from: Lee Bradley on December 03, 2019, 01:33:30 PM
That is true but have you tried pushing water through them when they're not running? Pumps on a manifold; one pump running will pull water from the manifold source and backwards (pump will have pull from the pump(s) on the manifold and push from the return side of the manifold) through any pump not running. All of my pumps pump through a check-valve into their circuit. Two into floor sectors, four into toe-kick heaters and one into a ducted heater in my bus.

I have the later model 50,000 btu (2007) Aqua Hot it doesn't have check valves

freds · December 03, 2019, 07:15:12 PM

I read somewhere that if you are forcing flow through an non-powered pump that it should be magnetic drive pump which is loosely coupled. It also handles a jammed pump more gracefully...

I will probably go for a flow detector to turn on a less expensive pump. Automation is cheap with a Raspberry Pi and hopefully lots of people will use what I publish as a canned solution.

Jim Blackwood · December 04, 2019, 09:23:56 AM

I'd much rather have a canned solution for a leveling system using the stock air bags. I think the coolant system lends itself to simplicity and basic thermostatic controls. The issue as I see it is that the demands for heat come from all over the interior plus the engine plus the water heater, making a centralized controller a bit complex to install. Then your control elements are large and expensive and there may be a lot of them. To say nothing about having to be a software engineer to fix the thing. So a cheap plug-n-play replacement with spares would be nearly mandatory.

The leveling system also lends itself to a simple solution using mercury switches but with only four corners and existing hardware seems a simpler implementation. A raspberry could have advantages.

Jim

freds · December 04, 2019, 10:38:05 AM

Actually I missed used the word canned, I meant open source and performing the automation with Node-Red control flows, so that it's always upgrade-able and modifiable.

Jim Blackwood · December 05, 2019, 11:11:39 AM

Um... for you maybe? For lots of the rest of us, if you can't just plug it in and use it the way it is without working through nested menus and computer screens it ain't gonna happen. Sorry, many of us just aren't on board with that stuff, missed the train, got caught looking at the scenery, sorta kinda accidentally stepped off kinda on purpose, etc, etc.

Jim

freds · December 05, 2019, 06:09:46 PM

Quote from: Jim Blackwood on December 05, 2019, 11:11:39 AM
Um... for you maybe? For lots of the rest of us, if you can't just plug it in and use it the way it is without working through nested menus and computer screens it ain't gonna happen. Sorry, many of us just aren't on board with that stuff, missed the train, got caught looking at the scenery, sorta kinda accidentally stepped off kinda on purpose, etc, etc.

Jim

I will also show a manual control solution LOL!
PS. You can also hopefully draft a younger offspring to get involved?

richard5933 · December 06, 2019, 02:32:36 AM

Quote from: Jim Blackwood on December 05, 2019, 11:11:39 AM
Um... for you maybe? For lots of the rest of us, if you can't just plug it in and use it the way it is without working through nested menus and computer screens it ain't gonna happen. Sorry, many of us just aren't on board with that stuff, missed the train, got caught looking at the scenery, sorta kinda accidentally stepped off kinda on purpose, etc, etc.

Jim

As much as I've read about your plans to build/customize your HVAC system, I'd have to believe you have what it takes to work through the 'nested menus and computer screens' to accomplish any of what's being discussed. It's not really any more complicated - you're just substituting electrons for refrigerant. Learn the new syntax and don't look back.

Jim Blackwood · December 06, 2019, 07:06:51 AM

Quote from: richard5933 on December 06, 2019, 02:32:36 AM
As much as I've read about your plans to build/customize your HVAC system, I'd have to believe you have what it takes to work through the 'nested menus and computer screens' to accomplish any of what's being discussed. It's not really any more complicated - you're just substituting electrons for refrigerant. Learn the new syntax and don't look back.

NOOOoooooo.......!!!! PLEASE NOOOoooooo.....!!! Um, see I have a long history with electrons, and more than in any other area it is liberally littered and scattered with the twisted remains of earnest attempts. The few successes have been dearly paid for in the byproducts of torturous experience. It just wears you out after awhile. The typical scenario is that it all goes great for awhile then at some critical point takes a hard left turn and goes downhill from there until I'm back at ground zero wondering what went wrong. Over 50 years now? Truly shocking! Now I'm not saying that stuff isn't great. Heck I just upgraded the SEFI in my '71 MGB sports car to the GM '411 ECM and hope to fire it up in the next week or so. BUT, if it malfunctions I will have 2 spare ECMs on hand that I can just swap out. That's about enough for me. And though the boy became a computer science engineer he won't work on my stuff. My few forays into programming were truly painful experiences, my brain just doesn't work that way.

I don't want more of it. I'd like less if I could, but there are just some things you can't have any other way.

This is a whole nother can of worms though. Thankfully there are a few signs that the computer wizards are beginning to realize that they need to make that stuff a lot more user friendly, so maybe they can reverse the trend. I hope so. The problem is that it's getting a little late in the game for it to do me that much good. So I'm really better off with stuff that I can fix with a soldering gun and a pair of pliers. Physical limitations are beginning to make themselves known and that microstuff is getting kinda hard to see.

Jim

Jim Eh. · December 06, 2019, 08:48:08 AM

freds · December 07, 2019, 07:18:59 AM

Quote from: Jim Blackwood on December 06, 2019, 07:06:51 AM
Physical limitations are beginning to make themselves known and that microstuff is getting kinda hard to see.

Jim

Hey Jim, just turn up the font size LOL!

uncle ned · December 07, 2019, 07:54:55 AM

Jim How or why would you try to computerize a MGB.

The only electronic part I have put on mine are electronic points because I cannot see good enough to set points.

The one good upgrade was the aluminum flow through head. it really turns a old MG alive.

The good thing a Mg did for me was it convinced Roxane "at Davids coach" that he needed one.

Now we are working on a MGA for him.

uncle ned

Jim Blackwood · December 07, 2019, 03:07:48 PM

Oh, well I'm one of those Dastardly Engine Converters. Probably even one of the ring leaders Ned. My MGB has been V8 powered since '88 and presently sports a supercharged and injected 340 Buick. It ain't exactly stock. I've run EFI since about 2000, first Ford, then Megasquirt and now GM because the hot rod community now knows how to get the most out of the '411 controller, which has the capabilities I need. My fondest hope is that once I have the basic tuning done I will be able to just forget about it. One of the best things? That controller now goes for about $40 at the pick-n-pull. So spares are cheap, and swapping one out isn't much harder than changing a relay.

Jim

freds · December 16, 2019, 01:02:33 PM

Still working on my design and in studying the documentation for my water heater I was looking at the following diagram and an idea occurred to me.

The above diagram is basically creating a back-water channel, if you close valve number four then all the flow goes through the heat exchanger, if you open it all the way up then it takes the least path of resistance from point one to point seven.

So, my idea is to use the same strategy with the preheat pump by replacing the adjustable valve with a check valve.

And to prevent an engine overheating feedback loop, that buswarrior warned about; we add a preheat cutoff sensor that creates an open circuit at 70-100 degrees and cuts power to the pump.

You could also add an indicator light after the cutoff sensor that will be on while it is preheating and off when at starting temperature.