sizing the boiler

Hilly

I used watts PE-RT pipe a couple of weeks ago to replace a kitec system. It was much nicer that the pex-b pex to use. I still think I like the Pex-a's I've used in the past a little bit better. The pricing was much better on the PE-RT and I will use it again.

heatingdpeng

to Snowmelt, I bought my pex from pexuniverse. I just found out that the pex and manifold is from China. I have listened to your guy, decided to use the right size of boiler. I bought CGA-5 Weil-Mcclain. 150,000 BTU input. Today I talked to my plumber, he insisted the main pipe loop which is connected to boiler has to be 2 inch. I look at the menu, stated that CGA-5 using 1" pipe for the rise of 20 Feet. Can anyone help me to convince myself to just use 1" is OK, thanks so much, please find enclosed my final design I handed to my plumber

Harvey Ramer

Without crunching all the numbers, pipe length, fittings, devices ect.. 1-1/2" would be the proper size based on the BTU output at a 20°. 1-1/4" will also work and may be the better choice if you are using a Micro Bubble air separator, due to the increase in velocity.

rick in Alaska

Did I miss something? I thought from the first post you said your heat loss was 63000, so why did you get a boiler that is over twice the size? You will not be able to get rid of the heat being produced, the boiler will short cycle, and you will be spending money on oversized parts.
Sounds like you need to get rid of your plumber also. 2" pipe is too big for that boiler size.
Rick

heatingdpeng

dear Rick, I recalculate the whole heat loss again, detail to every wall and basement insulation, come up the heat loss is 110763, which I feel more reasonable, since someone in this forum told me that base on my size of the house, it is unreal to have the heat loss only 63000, with CGA-5 the DOE is 117000, which close to my heat loss. Can any one give me some help, when you look at the CGA-5 menu, they show only need 1" pipe, but the note said 1 1/4, also my plumber told me the system pipe size is base on how many zone I have to supply water, for My 5 zone, I need 2", Since all the zone won't be using the same time, Maybe 1" is sufficient, if not, 1 1/4 is more than enough ?
thanks all the help, really learn something here

heatingdpeng

here is the cga-5 data sheet

JUGHNE

In your last "final pipe design" it looks like the boiler pressure relief valve can be isolated from the boiler by a valve. It should be right on the boiler with no valves between safety relief valve & vessel.

j a_2

The fellow who said two inch,ask him to draw out a simple hydronic diagram AND EXPLAIN IT…Pretty much, don’t think he can….Best send him back to burger king flipping burgers….That would be doing him a huge favor….And the future victims of the unskilled fake…Plumber/hydronic expert..he is notttt

rick in Alaska

For a 110,000 btu boiler, the general rule of thumb would be to use 1 1/4 pipe. This is for a temp drop of 20 degrees. This keeps the flow velocity around 4 feet per second. I am not sure about the cga manual showing using 1" pipe. Maybe they are running primary secondary? 1" might be a problem, but I guess you need to just follow manufacturers suggestions. But, if you went with the 1 1/4, you can't go wrong. Just will cost more.
Rick

heatingdpeng

thanks all the comment, I will take yours comment to use 1 1/4, it is make sense to me. For JUGHNE, do you mean I should move that boiler pressure relief valve to the boiler like enclosed picture ? also for the boiler by pass, what kind of valve I should buy ? full ball valve OK ? Do I need a check valve in that location to make sure the water go that way ? thanks all of yours help, grateful

heatingdpeng

should I fire my plumber ? I asked my plumber for the plumbing design, he never give it to me, so I design mine, and give it to him, and asked him for a list what to buy, so I can buy the materials. He gave me a list, there are 10 1" ball valve, but my design do not have so many ball valve, I asked him why, he said he is not going to follow my design, so I ask him what he has changed, can I get his version of design, he said he is too busy to draw, if I do not believe him, I can go to find someone else, he also said I bought the boiler too small (Weil Mcclain CGA-5), not listening to him. Can someone in staten island area, have new york plumbing license, want to give me a quote ?

icesailor

Does your "Plumber" ever go to any greet & eats with the boiler manufacturers? Study up on any online forums? Or does he get his latest information on heating from his friends at the corner saloon?

You go out and look at the specs of any boiler series you want to pick. It doesn't matter which brand or model. Anything you pick that matches your range of input/output will go from the minimum of 50,000 to 0ver 200,000. Most have a 1 1/2" outlet, and smaller/lower ones have 1 1/4" outlet/ inlets. There's a reason. You can't shove 10 ships out of a 5 ship harbor at once.

And you should be using the AHRI numbers. That covers all the unknowns that you and the "Plumber" don't know.

On any rating, take note of what is almost always noted with an asterisk, (*) as #3. "No additional sixing need be used for radiation, piping of pick-up unless unusual piping (ETC).

If you want to buy a new pick-up truck to cart yourself to work and a Sunday trip to the dump with trash, you don't heed a F-350 HD Dualie Diesel that can turn 105 MPH in under 13 seconds in the 1/4 mile. If you choose to get one like that, don't complain how much it cost to buy it, or how much to feed it. Those horses are hungry.

New Yorker AP-590's used to come through with only 1" IPS on the supply. You couldn't get any more water than that out of them.

bmwpowere36m3

So your asking the plumber for a design and list of materials to buy.... that should go well. No offense but, you should find a good plumber and let him do the work.

I would worry about the larger picture and not whether you need 1 or 10 ball valves.

j a_2

bmwpowere36m3 said:

So your asking the plumber for a design and list of materials to buy.... that should go well. No offense but, you should find a good plumber and let him do the work.



I would worry about the larger picture and not whether you need 1 or 10 ball valves.

Totally agree, As a homeowner, your job should be to seek out a competent plumber [ great thread here about just that} recently….Any one who lets you buy the stock and such is generally not a full fledged business…That is a huge red flag…
If and as all pricing is a huge factor,and your comfortable with your total design…And willing to take all responsibility beyond the mechanical work, try this….Work out a scope, get 3 quotes and go from there….Remember, thou its your design and you own it,the plumber is only responsible for his mechanical work…Personally I do not think that would work…But who knows….Huge difference between the drawing board and the dark dingy basement...

heatingdpeng

thanks all the comment. I called the plumber today, he is not even answer my call. He did the pvc piping, not even testing if there is leak. I already gave him 3 payments already, still got 2 more payment. it is final for gas pipe inspection and boiler installation and heating then final inspection. Do know know what I should do about him. Any suggestion ?

Jack

Confused, here. You have a job , yours, that you think is going sideways and are trying to rescue it by getting in the middle of the supply of materials. I would suggest that you have a calm sit down with this guy. Speak straight to him and see if your concerns are in fact well founded. If he is able to put you at ease, good! If not, then you have to move to plan B. Open, honest communication is the best bet. Sorry to go Gumbaiya on you, but see how it goes and please report back!

bmwpowere36m3

I guess I'm confused...

@heatingdpeng

You’re designing the system right? The whole system, from boiler to emitters (including layout, zoning, pipe sizing, valves, circs, air elimination, x-tank, etc...)?

So are you looking for a plumber who will take your design and do it (put paper to copper, lol)? If so, you should be very confident in your design... because the plumber won't be responsible if it doesn't work due to the way you designed it. I bet if you had 10 different plumbers, do the exact same system (per some spec) you would get 10 different installs that all work the same.

Being a homeowner myself and currently in the process of installing/piping my boiler... things don't always work out the way you draw it out on paper or things you overlook. And I’m an engineer…

I started with a rough idea of my system layout on paper, went to my local supplier and got as many fittings and stuff as I thought I needed. Well sure enough, I've been back so many times, I can't remember, for more parts. Whether I need more or I didn't get them in the first place. Granted, my supplier is totally cool and I can bring back what I don't use/need.

Lessons learned, I should have gotten 2-3x as many fittings (including ball valves) as I "thought" I needed.

RobG

Rarely have I seen a system with too many isolation valves.