DIY Hydronic plumbing and heat distribution

[freds]

I have been noodling away on a DIY Hydronic design and looking at parts and most of the PEX manifolds out there are 3/4 inch input and 1/2 inch output.

I just order in some PEX from Amazon without first visiting a local pumping store first to look at it and thinking that I will not want to run my heater zones over 1/2 PEX.

Suggestions?

Thanks

[sledhead]

I think the 1/2 " is to small and the last system I did was only 4 loops so all I did was use 4 x 1" x 1" x 3/4" gal. t's  with short nipples between each t for each loop . add as many as you need and you can find a better price on the fittings . Just use lots of pipe tape on the joints or to be safe use the pipe dope first and tape on the joints .

https://www.homedepot.com/p/LDR-Industries-1-in-x-1-in-x-3-4-in-Galvanized-Iron-Reducing-Tee-311-RT-1134/202310734

dave

[Bill Gerrie]

Very nicely done Dave. The only ting that bothers me is the galvanized fittings and mixed with copper. Corrosion over time as i have seen it in a house water system.

[buswarrior]

You have to be able to achieve minimum flow rate for the chosen coolant boiler, or it's overheat protection circuits will interfere.

And beware the "advertised" output ratings on any heat exchangers, a coolant boiler typically is limited to a cooler 160 degrees, not the higher temps likely intended by the "raters"

What is the temp rating for PEX and the intended manifolds?

What restrictions on anti-freeze chemical type are there?

Happy coaching!
Buswarrior

[luvrbus]

PEX is rated at 180F the 1/2 inch is ok the exchangers just flow so much with to much flow and fast flow the boiler won't keep up BTDT with high flow pumps  and you use boiler antifreeze for the best protection but people use other types 

[brmax]

Nice setup! Always a great topic.
Im inclined to think with our antifreeze coolant qualities we test, it can be fine for some parts we use, and these look decoupled.

One could build a copper manifold I suppose and have other sizes, yet a smaller outlet can positively act as a restriction in a positive way for us sometimes, and manifolds are one great place. Just my opinion with this liquid and a viewable part.

Have a great day
Its Friday!

Floyd

[Fred Mc]

You might want to loo at "gumpy's" system. I has a write-up on it and great pictures.

[freds]

You might want to loo at "gumpy's" system. I has a write-up on it and great pictures.

Link? A search on grumpy returns nothing.

[buswarrior]

Not sure if it still exists, won't connect.

Gumpydog is the word to drive the search, no "r" in it.

Happy coaching!
Buswarrior

[Jim Blackwood]

Is plastic in a heating system really a good idea?

You may not have considered the basic character of plastics. It is an amorphous solid, similar to glass in some ways, but the inclusion of plasticizers keeps it flexible. What are plasticizers? The simple answer is a solvent. As such, the plasticizer gradually leaves the plastic over the length of it's lifetime in a process known as Outgassing. When enough of it has left, the plastic becomes brittle. Everyone has seen this process in action. As far as I know all plastics are subject to it to one degree or another, depending on composition and section thickness. Heat of course speeds up the process.

So regardless of what the manufacturers claim, just keep in mind that is for new tubing under ideal conditions. Next year it may be less so, and so on until failure. So again the question:

Do you really want plastic in your heating system?

Jim

[sledhead]

I like pex 3/4" and it has worked for me for years

Very nicely done Dave. The only ting that bothers me is the galvanized fittings and mixed with copper. Corrosion over time as i have seen it in a house water system.

Bill because of the propylene glycol in the system I do not think there will ever be a problem or at least not in my life time

https://www.heatlink.com/

dave

[brmax]

Sledhead: Dave can you help and add to any floor applications. Like any mat for holding down pex or what have you seen you lean towards for some bus applications.
I think it was Gumpys if im recalling correct, that may have used plywood and routing, but to my knowledge there was not a lot of options in them early days.

Thanks

Floyd

[sledhead]

I installed 1/2" pex in floor heat in the M C I front to back with 8 " centers between the pex runs . 4 zones . worked amazing when driving for long drives , but not fast enough heat when camping . So on the Featherlite it has cozy heaters to speed up the heating time . There are pex mats out there now that most heating guys use today because they are easy but are not cheep . 

https://www.lowes.ca/product/flooring-underlayment/warmlyyours-prodeso-membrane-roll-162-sqft-33-x-492-330608916?&cm_mmc=shopping_google-_-6444645358-_-79852112827-_-pla-821049015547&gclid=Cj0KCQiAtrnuBRDXARIsABiN-7AzG988b9PEqb0fgtRZut6bjpojAe5u9nZ5xMkEsgTArLONfhi6k8IaAqDEEALw_wcB&gclsrc=aw.ds 

You need to research the heck out of the different systems for hydronic heat and cost it out before you spend any money , It is a amazing system if done right

dave

[luvrbus]

If it wasn't for my floor heat being a electric  hog (NUHEAT) the stuff works really good and fast with it on the Aqua Hot very seldom runs

[sledhead]

If it wasn't for my floor heat being a electric  hog (NUHEAT) the stuff works really good and fast with it on the Aqua Hot very seldom runs

yup ! the nuheat is fast and warm if your not paying for the heat .

what people do not under stand about water in floor heat is most times it can take from one - several hour's  to heat up because of the mass . but the mass is what keeps the heat .

I have installed infloor heat in lots of buildings over the years and it is amazing heat source BUT ... you need to set the thermostat and leave it alone .
one of my tenets in a commercial building had a ski doo dealership and between his girls in the showroom  and the guys in the back shop would play thermostat wars ..... Christmas eve day someone turned up the thermostat all the way up 95 f and they did not return to work until the 27th of December and when they came in to work it was 95 f everywhere .... as infloor heat heats up everything not just the air like a regular furnace . long story short with the heat turned off and all the doors open during business hours it took 3 days to get the temperature down to 72 f 

dave