New House - New Pex w/Furnace - Strange Set Up?

JayPoorJay

Hello All... 

First - THANK YOU! I am super grateful for forums like this. Life savers. Thank you ALL for sharing your hard earned wisdom and experience!

So here's the thing. Wife and I just purchased and moved into a big ol Victorian/Colonial style (and sized) house on Staten Island NY. Beautiful thing.

Q's... The last owner (a friend) had a friend of his upgrade from an old oil boiler to a high efficiency gas unit. It's a 2 zone system (can live with that) using orange PEX,,, hot water to cast iron radiators (around 10 of them I think 5/floor). But here's the thing. In the basement - the PEX leaves the furnace/boiler (first floor in this example) and goes into the first radiator, then leaves it, on to the second, then leaves it - and so on.

The PEX is strung (naked) around the entire circumference of the basement (seems like super long runs) and by the time the PEX and water gets to the last radiator the water is pretty much cold and the last radiator never heats up. Well, barely. And the one just before that, about the same. Then, from there, it returns to the furnace. The number of twists and turns is 'impressive' (not) and this is NOT a climate controlled basement. The PEX is actually heating the basement.

Is this "normal". Or, is more of a trunk way the norm where a 1 inch or 3/4 pipe would run down a centerish line of the house where branches shoot off, then back, for water flow???

mattmia2

How is it connected to the radiators, is there just a fitting on each end or do both pipes come in to one fitting? This can work if the math is done correctly but you can't just hook it all together and expect it to work.

EdTheHeaterMan

What type of radiator?

This is normal for copper tube w/Aluminum fin baseboard radiators. This will certainly NOT work for cast iron standing radiators
I just used this illustration from one of my classes to explain 4 different piping designs.
The only one that has what you describe is Baseboard style series loop heating on the bottom right. I'm guessing that you have some other type of radiator. Post some picture of the radiators for more help

Jamie Hall

Not a hope. That type of system pretty much has to be piped with a nice generous main supply line (preferably insulated) and an equally nice generous return line. That way each radiator gets equally hot water and can do its thing. Further, that way if one radiator is more enthusiastic than one wants, one can partly close the valve and calm it down.

hot_rod

Too many cast radiators in series would cause that.

Fin tube, you can get away with about 70' on a loop.

A homerun system is ideal for cast or panel radiators. Each read gets the same temperature supplied to it.
And allows radiator valves at each unit for temperature control.

EdTheHeaterMan

It sounds like there might have been a gravity system with big ol' head knocker pipes in the basement. Then someone got the great idea of putting smaller pipes in the basement and allow for more head room. Who cares about comfort in the rooms upstairs. Look at how much head room you have now!

JayPoorJay

mattmia2 said:

How is it connected to the radiators, is there just a fitting on each end or do both pipes come in to one fitting? This can work if the math is done correctly but you can't just hook it all together and expect it to work.

You guys are amazing! 

I wasn't getting email notifications so I'm just seeing these answers. I will try (where needed) to reply to each answer and questions with quotes.

Good Morning, Matt... In the basement there are what looks like the cut ends of the old cast iron piping which head up to the floors and their respective rad - in and outlets.

At the connection(s) in the basement (at the cut ends) the PEX (which is much small OD than the cast) comes to the pipe with a doped fitting from PEX to cast in (from memory) a couple of ways - straight and 90's unions. On a couple on the first floor the PEX is exposed and runs right to the rad inlets and outlets.

AT the furnace it's all new copper - then looooong runs of PEX (uninsulated I'll add). Only on the vertical runs (for the most part) is the old cast iron pipes.

JayPoorJay

EdTheHeaterMan said:

What type of radiator? This is normal for copper tube w/Aluminum fin baseboard radiators. This will certainly NOT work for cast iron standing radiators I just used this illustration from one of my classes to explain 4 different piping designs. The only one that has what you describe is Baseboard style series loop heating on the bottom right. I'm guessing that you have some other type of radiator. Post some picture of the radiators for more help

Great images! Thank you.

Yes. Allllll cast iron standing radiators.

Pictures will be on the way. I'll do that tonight.

JayPoorJay

hot_rod said:

Too many cast radiators in series would cause that. Fin tube, you can get away with about 70' on a loop. A homerun system is ideal for cast or panel radiators. Each read gets the same temperature supplied to it. And allows radiator valves at each unit for temperature control.

Good Morning, Bob...

I would like to hear more about this homerun system, and systems like it. I am really interested in the radiators heating up uniformly and a water stream that isn't spending much of it's heat, just trying to stay hot, as it makes this super long daisy chain loop. At the same time,,,

Money (especially right now) is an object. Not a lot of major problems, but basically basement to water off the roof (Dutch/Yankee gutters) things need addressing.

There are no young ones running around, both my wife and I are from a little further north, Western Massachusetts, so we are used to a sweater and wool socks in the winter months.  Believe it or not, growing up we used two wood stoves for heat. No or nearly no utilities. Good ol wood.

Anyways, I work with my hands a lot. I plan on doing most if not all of the work around this place myself and with a hired helper when needed,,, then a few friends and what not that SAY they will help, lol

Can those manifolds be found used?

From YouTube and the confidence y'all inspire, I like new tools, I'm hoping I can do this myself!

Hope y'all will stick with me 😁

JayPoorJay

EdTheHeaterMan said:

It sounds like there might have been a gravity system with big ol' head knocker pipes in the basement. Then someone got the great idea of putting smaller pipes in the basement and allow for more head room. Who cares about comfort in the rooms upstairs. Look at how much head room you have now!Yeah 

Yes, exactly that... Some of the rooms, some of the time in certain situations, it's not going to work...

There are a LOT of 75-80% jobs around here. Good intentions and needed change - but not so thought-out or worked to completion... Lots of work ahead of me...

There is extra PEX around the house and LOTS of PEX in this current setup, and a 2 zone set up as it is.

I'm wondering if I can basically work with what I have and redesign this thing? If I set up a straight shot from the furnace to the front and back of the house, a TRUNK of sorts, it seems for inlet and out let I could hit every radiator, in and out, very easily.

What would it take to make this change?

Can T's be used with PEX? Place a T,,, going 90° off the furnace towards the front and back of the house and branch off left and right with T's to each radiator vertical out near the basement walls? Then back again from each radiator into a return line - back to the furnace???

Sorry y'all... I do NOT know proper language and terminology.

What do I need to be thinking?

EBEBRATT-Ed

@JayPoorJay

Sounds like you have some work ahead but it's all fixable. The most difficult part would be the old steel risers' weather to keep or tear out. Sounds like they may have to stay to avoid destruction.

There are a lot of different ways to pipe hot water and they all work if done right. The diagrams @EdTheHeaterMan posted show the most common configurations.

To get this right you should do:

1 a heat loss of the entire house
2a room x room heat loss
3 A decent sketch or print of the existing piping and note any old risers that cannot be changed
4 inventory of the existing circulators and boiler

You may end up piping the first floor one way and the second floor differently.

Sounds like he piped it like a series loop which will run out of water temp and probably flow before it gets to the last radiator.

Some of the above steps may seem unnecessary but you only want to do this once and do it right.


You really need the heat loss from this the radiator sizes can be checked (I am sure they are oversized which is good). Once you know the HL you can figure the supply water temp needed, pipe size, flow rates pump sizes etc. It all comes from the HL

JayPoorJay

Hi Ed. Yes, there is work. There certainly is.

I came home and looked at it. Didn't get any photos together but will.

The risers I think I will leave. It would take a LOT to go that far and (in my inexperience) I don't know what I would or what harm is in leaving them.

How does one do and record heat loss ideas? What I know is that the PO replaced all windows, shot insulation into the walls from the attic to basement... From what I understand its "balloon" style framing which made it much easier to do. They did quite a bit. Drafts we can feel are mainly from under a few doors. But nothing major.

The radiators are huge. All of them except two. The one in the upstairs bath is a small standing cast iron and of course the hottest (by far). It is the first stop off the furnace in the basement in the daisy chain configuration... And of course, the other small floor style baseboard rad (but not copper with aluminum fin,,, it's heavy cast but horizontal shaped) is the one in the kitchen which is the LAST stop radiator in the first floor daisy chain set up. The kitchen is very cold. 3 exterior walls and the WORST under door gap. Many drafts there.

The furnace is running a lot and it hasn't gotten REALLY cold here yet - and the stat is set to 68...

Q: I was looking at manifolds today and they are in the budget - IF that course was taken. More PEX is as well... The system is now 2 zones. And there are what I think are small pumps labeled floor 1 and floor 2. How necessary and effective are manifolds, say a 5 spout type, one 5 for each floor? Does it make that big a difference?

I have all kinds of questions...lol

Y'all are in trouble 

EBEBRATT-Ed

A Lot of us used the Slant Finn ap but now that they are gone not sure. Someone said it is still available. Others will comment. It was easy to use and decently accurate.

You measure windows, doors walls and ceilings and floors. You have to make some assumpitions on insulation from what you can see and can't see. I am sure you have plenty of radiation.

The heat loss will ensure you get the right pipe size, flow and water temp

EdTheHeaterMan

Try this load calculation form for your boiler sizing
https://docs.google.com/spreadsheets/d/1PFPIx3655H7xFTUc2HwuhJa4PCOqAcqw8E5F6woKdN4/edit?usp=sharing

This is a whole house form however, you can do each room on it one at a time of you like. Sorry there is not a room by room form yet. This is done on a Google Sheets document and will do the math for you . all you need to do is fill the dimensions in the light blue colored cells. All the white cells will auto fill and auto calculate once the blue ones are filled in. Leave any blue one blank that you are not using so you don't cause an ERROR# in a cell lower down on the form.

mattmia2

How big is the pex between radiators? If it is large enough to carry the flow for the whole zone yo could just add a bypass with a ball or globe valve across each radiator in the basement to divert some of the flow through the radiator and keep most in the main loop. Supply and return mains might be less expensive than a manifold if cost is that much of a concern and the existing pex is too small.

ethomas

I’ve used coolcalc.com to do heat loss for a couple of houses now. It seems to be pretty accurate if you make aggressive assumptions (if you’re not sure about an R-value, choose a higher number), I think it has a large safety factor built in. You can do room-by-room and it’s free to preview the results. 

JayPoorJay

Hey Y'all! Thank you.

For heat loss analysis I think me and my Lady (an accountant and former Detroit machinist - long story) will give it a go with the spread sheet. For now, after such a large investment, we can't make any big change$$$ anyways really, and feel pretty good about the equipment that is here, just NOT so good about the way that things have been rigged up and installed. 

I think (pretty sure) that it is 3/4 PEX throughout. Then 1 inch copper around the boiler. I am anxious to provide y'all with some photos. I also shot a video last night, and will be posting a YouTube link after work.

Cost is a concern BUT a friend and I (a building engineer here in NYC but without the exact experience of actually installing stuff like this in residential) expect to do this ourselves. That is, reuse of the PEX stuff, reroute the piping, trying make shorter runs of PEX - with the goal of having each rad having a DIRECT RETURN set up. I'm feeling pretty confident and will be back with more questions and needed direction.

That next to last rad is that ODDBALL rad in the kitchen horizontal, but I don't think it's finned - it's heavy thick steel. The other couple photos are typical of the size of rads in the house...

Thank y'all so so much! 

Are these the pumps?

mattmia2

That last one is cast iron baseboard like Baseray or similar. It has some fins cast on the back. That little section of it won't have a lot of output even if you get it the right temp water and won't balance well if it is on the same zone as cast iron radiators.

That first one is a CI radiator with a cover, correct, it isn't a convector where there is a horizontal element near the bottom of it?

A quick and dirty way to at least get some heat before you can do a repipe would be to run 1" copper or 1.25" pex to the center of the loop and connect that to the return and connect the other end to another supply. It wouldn't get it all balanced but it might be enough to limp along until you can shut it all down to repipe it for a few days.

JayPoorJay

mattmia2 said: A quick and dirty way to at least get some heat before you can do a repipe would be to run 1" copper or 1.25" pex to the center of the loop and connect that to the return and connect the other end to another supply.

Ok! This is what I was thinking... So let me try and get clear on what you mean.

So, temporarily, thru this winter - I can reroute the first floor TO RAD flow after the first two LARGE rads at the front of the house. Rerouting them into a first floor return? Then, T into the 1st floor main supply (can brass T's be used???) diverting water directly to the 2 smaller rads and 1 oddball in the kitchen at the back of the house? Then again, to a new return line.

Can I use T's and will hot water flow properly thru a T?

hot_rod

this

Ironman

Does the pex have an O2 barrier? If not, you need to remove all of it and use some that does.

It will be printed on the tubing if it has an O2 diffusion barrier.

JayPoorJay

hot_rod said:

this

Got ya. But what goes here, and be specific, lol

What achieves the split? Can I use a T which would give 90s,,, or is there some sort of Y splitter? I guess I worry that the H20 would favor one direction over another.

JayPoorJay

@Ironman

This what I'm seeing

mattmia2

it is raised temp polyethylene and it is oxygen barrier. not pex, will need different fittings than pex.

The split can be a tee. Balancing valves would help too but this is just a stopgap, it won't be great but will be better.

JayPoorJay

Hey Y'all...
Again, I am super grateful for your time and attention... I just made a quick YouTube video that hopefully give a better idea of what I am looking at here. 

Completely open to ideas, corrections to my thinking and suggestions on where to go, or NOT go, from here.

Deep bow, many thanks!
https://youtu.be/sock7CMP8sU

Ironman

As mentioned, that’s PERT tubing, not PEX. If it’s the Roth brand, you can use crimp or expansion fittings with it.

The two problems that you have are the fact that it was done in a series loop and that it’s 5/8”.

I’m gonna include two charts: from one, you can calculate the output of each radiator; from the other, you can see many btus the pipe will carry figuring that 1 gpm = 10k btus. So, if the pipe carries 2 gpm that = 20k btus, etc.

With the radiator chart, use 170* average water temperature. That means you multiply the surface are of the rad and multiply that times 150 to get the btu output. From that, you can see what size line you need for each rad as well as the size needed for all the rads connected to the main line feeding them.

I’d highly recommend that you pipe it reverse return (first on last off) which will give equal temperature to each rad.

JayPoorJay

Ok. Mistakes (and there will be lots) noted.

For PERT or polyethylene tubing/piping what kind (specifically) connector and crimp is used? I would hate to get things apart and even back together (especially considering it winter) and finding that I used the wrong stuff OR I have to wait days for the RIGHT stuff, or both...

@Ironman - I've sent the charts to my Lady (the accountant, lol) and she and her Ma are doing the math as we "speak". Here's the thing, her and I have kinda talked about it, I think that when we do the math, and let's say we need a smaller diameter tube all around, unless it's a GROSS difference in what we do and should have, once all the numbers are crunched, we might just stay with what we have rather than ripping everything out and redoing. We don't like what inefficiency does environmentally,,, but we can pay the BILL, if you know what I mean? It's a tough choice.

Then again, if after we settle in, we take another look over the second String and Summer, we might revisit the idea of the RIGHT sized tube and start over.

So please, a link or an example that will point me in the exact right direction of the right TYPE/STYLE connectors, clamps and tools will help a million...

Again. Thank you!

Ironman

The 5/8” tubing is the equivalent of 1/2” copper tubing. It’s way too small to carry the load.

O2 barrier PEX or PERT is not that expensive and as I mentioned above, Roth PERT uses the same fittings as PEX. Any plumbing supply has them.

It makes no sense to use the same tubing over again when you re-do it if it’s too small; you’re gonna have the same results as you have now.

The 5/8” tube may be big enough to run branches to the rads off of the mains, but it’s not big enough for the mains. They should be at least 3/4” or 1”.

A 3/4” pipe carries twice as much as a 1/2” and a 1” carries twice as much as a 3/4”. It’s not a minor difference.

The laws of physics will not bow to economic considerations.

mattmia2

Also, if you watch the video, that install either wasn't inspected or the inspector didn't look because unsupported tubing draped all over the place like that is not allowed.

JayPoorJay

Understood x2...

I'll see if it's Roth when I get home.

For some reason I assumed (and you know what they say about assuming) @Ironman that you were saying the 5/8th was toooo big... But too small, ok. I hear you.

New pipe/tube is not out of the budget,,, redoing it (for now) is out of the budget time wise with a NYC schedule - for now. Then, there are lots and lots of things on the exterior of the housethat need addressing post haste,,, so we'll see how it all shakes out.

For now, I would like to get a few T's and try to redistribute the way the water is flowing, a temporary thru the winter "fix"...

And yes, I agree, it's a sloppy sloppy job - similar to the way the electrical was run. Sloppy work.

mattmia2

when you split it, try to make the bog radiator on the side with 2 and the 3 radiators the smaller ones. 2 in series isn't so bad, 3 in series, the 3rd probably won't heat so well.

JayPoorJay

With right crimps - will THIS connector (link below) work for me? With the 5/8ths PERT tube I have?

Is it possible to make text LINKs in posts on the forum?

Just to say - for now, this winter, I want to reroute a couple sections of existing piping in the system and make two smaller loops for the 2nd and first floor radiators. Basically splitting the existing set up on each floor and two in the best way I can.

https://www.supplyhouse.com/Everflow-PXTE0058-NL-5-8-PEX-Brass-Tee-Lead-Free

Ironman

Yes, that will work, but you’ll also need 5/8” crimp rings and a 5/8” pex tool.

5/8” is not a common plumbing size, so you may have some difficulty finding those items. Get everything on hand before you attempt anything.

Ironman

The crimp rings which were used on your pipe are the Otaker pinch style. If you can find those, you’ll only need one pinch tool which will work with all sizes up to 1”.

JayPoorJay

Got it... Many, many, many thanks!!!