System plumbing change


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Old 01-07-15, 12:08 PM
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System plumbing change

I have a hot water heating system that I put in incorrectly years ago. The zone valves are junk and I have bought new ones. I want to remove all of the old piping and build it like the one pictured in the link, on page 29 figure 6-14

http://www.caleffi.com/sites/default...dronics_10.pdf

I don't know if the link will come up as blue or if it will have to be copied and posted to the browser.

In the picture the header is suggested to be generously sized. Can anyone tell me how to size a header? I assume they are talking about the diameter of the header pipe. The hydraulic separator has inch and a half ports on it. The header pipe going into the separator should be at least inch and a half. The other side should be larger?????, but by how much. The header on the right side of the hydraulic separator as you are looking at it will have 7 zones coming off it. the first two will be for in floor heating with one inch leaving and returning and a Taco 007 pump on each one. The other five will be Honeywell zone valves V8043E. Two will be one inch and four will be 3/4 inch. Don't the zone valves have a flow rate of one and a quarter GPM or so. I will be using a Bell and Gossett series 100 pump where the pump is pictured on the conventional boiler. Max flow of the pump is 33 GPM, Max Head 8 feet, max pressure 125.

Can anyone give me an idea on how to do this?
 
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Old 01-07-15, 01:59 PM
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build it like the one pictured in the link, on page 29 figure 6-14
Can you tell us why you chose that particular configuration?
 
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Old 01-07-15, 05:31 PM
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I had another design and showed it to someone and they suggested the one from Caleffi. And not being an expert at all I considered using the Caleffi design.
I had asked others for help in designing a system and received no reply's. I am not fond of Caleffi's high prices for their equipment though. That separator and thermobloc pump are very expensive.I think I did see another design or two and did not like it for some reason or another. I have the old expansion tank and am thinking it is not compatible with the separator.

Is there another design by a professional that would do the same job. Maybe simpler and easy to understand.
 
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Old 01-07-15, 05:43 PM
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I had asked others for help in designing a system and received no reply's.
In general, free advice is worth what you pay for it. And those who are in the business of designing heating systems generally do get paid.

There is so much you need to learn... don't know where to start.

You're not planning on doing this in the middle of the winter, are you?
 
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Old 01-07-15, 06:00 PM
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I do not plan on doing this in the winter. I wanted to get a head start before spring.

I am trying to get some professional help locally but am having trouble finding someone who will combine two systems.

It's easy to find someone who will come out and throw in another boiler. I want a gas boiler and gas just came down our street a couple of years ago. I need to run a gas line to the boiler room also. This is a big job so I would like to do some it myself if possible.
 
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Old 01-07-15, 06:07 PM
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So you're saying that you are changing from another fuel source over to gas then?

And you will be starting from scratch?

having trouble finding someone who will combine two systems.
What 'two systems' are you talking about?

Why not start by describing what you've got there. Make and model of the boiler, etc

There's not much point in designing something if we don't know everything!
 
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Old 01-08-15, 04:17 AM
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What I currently have is a Buderus, Logano G201 Coal or wood fired boiler that I have been using since 1987 to heat my house. The G201 is the new number for my older boiler, the only difference is the G201 has more insulation between the sheet metal around the boiler and the boiler casting. It is plumbed together with a Burnham America, oil fired 115-140 MBH boiler. I am heating a 28' by 42' split entry house. (two levels) With the capability to heat the 24' by 37' attached garage. I have a unit heater hanging in the garage that was never plumbed in. I have heated this house with the Buderus boiler all but two years and a week here and there since 1987

I would not say I am starting from scratch, I want to continue using the Buderus wood or coal boiler and replace the oil fired boiler with a natural gas fired boiler, preferably a high efficiency one. I want to change the way they are plumbed together. They are currently plumbed together with two sets of zone valves, one set for each boiler. That was not a very good design. It worked but not a good design. If the oil boiler system was running, the oil boiler pump would pull the return water back to the oil boiler, but hot return water would still go to the wood boiler also. When the wood boiler got hot enough the wood controls would take over. The oil gun would still heat the water but the wood zone valves would open and close on call heating the house.

I have seen a lot of designs where the wood boiler is plumbed to send the hot water to the return side of the conventional boiler, the conventional boiler then sends the hot water to the system. The califfi design would make it easier to change out a boiler if needed, that is what I liked about that design. I had thought about leaving the oil boiler in place just changing the plumbing, now I am thinking about doing it all at once.

Size wise, boilers what I have now is working. If one was replaced I would guess it would be roughly the same size. If I knew how to size that supply manifold I could most likely do it myself. Supply House only lists one hydraulic separator. So size wise that is what is used in an average sized house?????? Just guessing.

I have learned over the years that installing an efficient and properly operating system is not as easy as connecting some pipes to a boiler and firing it up. Any knowledge and skills you folks are willing to share would be greatly appreciated.

If you are willing to help on this, and I did not give you enough information, tell me what you need. Thanks
 
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Old 01-08-15, 03:21 PM
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I watched another Caleffi u-tube video, over an hour long. One hour into the video they talked about Hydraulic separators and told how to size the pipes in the supply header. You use the GPM in the primary circuit and secondary circuit. which ever circuit has the most GPM, use that number to size the header pipes that the load comes from after the hydraulic separator. In my case I need 2 1/2" pipes. There is a chart that gives you the number based on the GPM of your pumps. Entering the separator I figured on using 1 1/2" pipe. If you want to watch the part on the hydraulic separation move the time forward to 1:00:00. The last part is ten minutes long.

https://www.youtube.com/watch?v=BJ4H...CRlRdg&index=1
 
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Old 01-08-15, 04:58 PM
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In my case I need 2 1/2" pipe
I kinda doubt that.

Piping is sized by the flow requirement and the amount of BTUs you need to move.

I seriously doubt you need to move that many BTUs that you need 2-1/2" pipe. That's HUGE!

Have you done a heat loss estimate on your home using Manual J procedure?

If not, I can guesstimate based on the square footage of your home... how big is it? Note that this is just a GUESS...

There's tons of good info at this website:

Comfort Calc

In particular, this page talks about pipe sizing:

Comfort Calc
 
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Old 01-08-15, 05:05 PM
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Jerome, how did you determine that you need to flow EIGHTY GPM?

That amount of flow would be able to move EIGHT HUNDRED THOUSAND BTUs!
 
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Old 01-09-15, 04:13 AM
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I kinda doubt that.

I would not think so either. That is what I understood from watching the Caleffi video when it said to size the pipes by the maximum flow of the pumps on either the primary side of the system or the secondary side. whichever has the greatest flow. The Pump on the wood boiler would be just getting hot water to the manifold and the pump on the conventional boiler would be moving the water through the zones. If I used two Bell and Gossett series 100 pumps the total GPM would be 66. I know that would not be 66 GPM through the system. even one pump would not move 33 GPM through the system. The water should be restricted some what as it flows through the pipes so heat can be removed from the water. If I used the GPM flow on the secondary side I could use two inch pipe. This pipe would be just on the header and would be about three feet long. One on the hot side and one on the return side of the header. And from what I have read the pipe needs to be large enough to keep the pressure the same on both sides of the header as the pumps moves water from one side of the header through the system and back to the return. The two taco 007 pumps I would install moving water from the supply side through the in floor heating of two zones would be capable of moving the water at the rate of 17 GPM each. I still don't think water moves that fast through the system, that's is a lot of water. Here is a short u-tube of how a hydraulic separator works if you care to watch it.
https://www.youtube.com/watch?v=qTm2Y6h-aH8
How does pressure in BAR differ from PSI?

I have not done a heat loss estimate, I am trying to get a local professional out but he has been busy lately because of the cold.

My house is 28'X42' two levels. one level half in the ground on one and a half sides. I have a 24 X 37 foot attached garage I want to heat occasionally.

I will look at the links you provided.
 

Last edited by Jerome; 01-09-15 at 04:48 AM.
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Old 01-09-15, 04:45 AM
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Jerome, how did you determine that you need to flow EIGHTY GPM?

My flow would be 66 GPM. But maybe 33 would be more realistic and that would put me in the two inch pipe size for the manifold.
The video said take the total flow of the pumps in the primary side or the secondary side and which ever flow is the greatest to take that flow and match it with the chart to determine pipe size. The pump on the wood boiler only supply's water to the manifold, through the separator and back to the wood boiler. So maybe using the one pump on the conventional boiler would be the thing to do. Then I would size the header pipe using the GPM of the two Taco 007 pumps of 17 GPM each.

The current oil boiler I have has a 1 1/4" inlet pipe and a 1 1/2" supply pipe. A boiler I had at another house had a 1 1/4" inlet pipe and a 2" supply pipe.
The Buderus wood boiler has a larger supply pipe than the inlet pipe. The bell and Gossett series 100 pumps I use all have 1 1/4" flanges on them. I have always wondered why does the supply side of the boiler always have larger piping?
 
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Old 01-09-15, 07:59 AM
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No...

You're not understanding the way the pumps operate.

You will NEVER achieve the MAX GPM when the pump is installed in the system.

The only way you you can get that max flow is with the discharge of the pump into the air, with ZERO RESTRICTION (aka HEAD).

Study PUMP CURVES.

You need to also understand what a SYSTEM CURVE is, and the OPERATING POINT of the pump.

The Caleffi guy showed this in his presentation... where the SYSTEM CURVE and the PUMP CURVE intersect is the OPERATING POINT of the pump.

If you've got a 100,000 BTU boiler you will never need more than TEN GPM total.
 
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Old 01-09-15, 10:13 AM
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I will look at that pump curve chart. That must be why boilers have reduced down to a 1 1/4" supply pipe leaving the boiler for a zone valve system. Would 1 1/4" work with two or more 007 Tacos pulling from a 1 1/4" and returning to the return side?
 
 

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