Looking for someone to walk me through an upgrade project.

cnmdesign

Hi to all

First Post

For some reason my 60 year old Holiday Burnham NG Boiler after 22 straight years of worries free use, crapped out on me and I need to replace it. My old system was a 95’ BaseRay cast iron base board shot gun system with one thermostat and one continuous running circulating pump.

I would like my new system to be a Burnham K2-100 four zone, zone valve system with one Alph2 ECM pump.
Zone one will be a high heat (180) in joist pex-al-pex loop.
Zine two will the old Baseray moved to the basement.
Zone three will be an in slab out building.
Zone 4 will be a 50 gal Burnham indirect HWH.

Question .. Setting up a reverse return distribution system using two straight 1" runs down one side of my ranch in the basement and running four 3/4", nine joist bay loops starting at the supply run and ending with the return run for zone one. Each loop will have a diverter T, flow meter/valve and an isolation/purge valve.

Do I need to put in a balancing valve at the end of the two 1” straight runs?

Do I have to put in a zone valve in each of the four ¾” sub loops even though I have a flow meter/valve?

If I can use my flow meters, should they be Velocity or Volumetric?

Looking for someone with smart phone to face time and help me through this project.

Wife is on my tail. Starting to get a little cold here in SE Ohio.

Thanks

hot_rod

Maybe a drawing of what you are thinking. if the PAP loops are all the same and on one zone, no need to have a balance valve on each loop unless you need isolation or want to adjust output loop by loop.

i assume it is a single temperature system?

The Alpha will know when ZV open and close and adjust output accordingly, assuming it can handle the entire connected load.

ideally a new or retrofit system starts with a heat load calculation, all the equipment should size close to the load.

Then a design showing actual required output at every zone.

Then calculating piping runs and amount of radiation.

More often than not boilers were oversized to the loads, sometimes grossly. Only a load calculation on the building in it's current state will give you the accurate number.

Oversizing the equipment can cause short cycles, loss of efficiency and higher that required fuel bills.

bob eck

Hot Rod
Would this type of job benefit from a 20, 30 or 40 gallon hydronic buffer tank?
How many showers?
Does he need a 50 gallon IDWH. Burnham has a 35 gallon IDWH where he could store the water at 140 or 150 degrees and use an mixing valve to get the water back to 120 degrees.

hot_rod

More pencil pushing first. Need to look at the heat emitters see if they can maximize that condensing boiler.

The smallest load compared to lowest turndown, are a few thoughts.

Wonder if that boiler has ramp delay or limiting features, that could play into the decision.

cnmdesign

Boiler has been sized by two installers. One said he can't take on the job and the other wants just over $6K for install labor. Only hooking up two zones this winter, zone one and four and zone one is the old, all ready installed, 95' base ray run.

Only two showers in the home. Zones one, two and four will require higher temps. Using Ultra-fin in zone one next year and will be using the base ray cast iron from up stairs, down stairs next year as well. I know this will not be the best use of the system this winter but we need heat in zone one and four now.

What about the need for a balancing valve at the end of the two 1" runs?

Zman

I am not sure why the design is revolving around an Alpha circulator.
You should first do a heat loss calc, This will determine the boiler sizing and water temp required for each zone.
Then make a drawing and ask for feedback.
You are going about this backwards...

cnmdesign

The boiler has been professionally size by two different contractors. It's not an issue. Temp will be 180 in three out of four zones or what ever lower temp the system feels is required to maintain the required temp for that zone.

My P/S will be a four, zone valve distribution system located on the link below only requiring one circulating pump. The tank will be 14 gal.

http://www.blueridgecompany.com/radiant/hydronic/780/rht-prefabricated-dominator-zone-valve-panel

Here is another sample, only I will be running my water heater off one of the zones not off the primary.

https://us.v-cdn.net/5021738/uploads/posts/12900/boilerplan-rev1.jpg

Brewbeer

Describe what the contractors did to size the boiler. This is super important, and some contractors take shortcuts, because a proper heat loss calc takes a few hours to complete.

cnmdesign

Both used Manual J. Were there over an hour. I had all ready pre measured everything.

Solid_Fuel_Man

What are the numbers?

Canucker

At a 25 btu/ sq ft ball park heat loss estimate, that boiler can heat a 5640 sq ft building. That's a big building.

cnmdesign

House 3000 sq/ft
Out Building 2400 sq/ft

Zman

Your description is impossible to follow.
Draw out what you are considering and post it.

mikeg2015

You have lots of issues.

Step 1 - you have a condensing boiler, unless return water is under 130F, you are wasting your money.

Step 2 - use outdoor reset and try and operate the 180F zone at 160-170F.

Step 3 - pipe the zones with different emitter types and temperatures in series to maximize delta T.

Step 4 - make sure the boiler can handle a 50F delta T and check the minimum flow rate. That boiler may not be a good choice. Some of the new HTP boilers and Lochinvars with welded fire tube HE are better options as their HE can handle wide delta T's. I think the K2 is aluminium heat exchanger with gaskets between sections. If so...run, run away. It will leak and need frequent gasket replacements.

Some can, some cannot handle that large of thermal stress across the HE.


Bottom line, your goal is to minimize return water temp at all times. If you are over 130F, a condensing boiler is no longer condensing and is around 88%. To hit 95%, you need return temps normally around 100F. with in floor radiant, you can achieve 85-90F and hit 97%.

Compromise and simplist control scheme is probably targeting a 50F delta T at all times and run a return water temp from 85-130F using outdoor reset. The system becomes somewhat self balancing that way. The just use 3 way thermostatic valves to set the max zone temps, then regualr zone valves. Pump is set on constant pressure with a end loop pressure dependent bypass.

Extra credit for using a reverse return piping scheme so it's almost self balancing.

cnmdesign

Mike

Thanks for your concern. Where in this video would those gaskets in the HE be located? Thanks

https://www.youtube.com/watch?v=btpGf5kVvKI

Ironman

I second the recommendation to use a boiler with a fire tube heat exchanger. The Gianonni/Sermeta requires a lot more maintenance and is an inferior design compared to a fire tube. Burnham offers both if you wanna use that brand.

Also, please heed the advice about ODR and running lower water temps. The cooler the return water temp, the more efficient the boiler is.

Suspending tubing under a floor and running 180* SWT with a mod/con boiler makes no sense. Use good quality extruded aluminum heat transfer plates and you shouldn't need more than about 120* SWT for the floor. You need the plates to CONDUCT heat from the tubing to the floor, not CONVECT or RADIATE it. The only place a radiant floor RADIATES heat is from its surface to the conditioned structure.

It would help, and is even necessary, to know the numbers from your load calc. That's the foundation for designing EVERYTHING in a heating system, not just sizing the boiler. Without that, we can only give you general answers.

cnmdesign

Building a four zone, one ECM system but will only be activating two this winter. Main floor heat and indirect WH. Will not need the other two till next winter. Is it OK to grow into a system or do I need to use all the zones this winter? Also, when sizing for an ECM, do you add up the head loss for all zones?

NY_Rob

^ What are the head figures for each of the zones?

cnmdesign

Is Caleffi a quality product or just high priced?

Ironman

Best you can buy.

Solid_Fuel_Man

Caleffi is very high quality from what I've used.

That's not to say there are not other high quality products out there, but if it says Caleffi in the box it's pretty much a guarantee.

Their Z-one zone valves and diverting valves are a personal favorite.

cnmdesign

Deleted

Ironman

To give a generalized answer: 1/2" pex will flow about .7 gpm on a 300' loop with a ups15-58 circ; 3/4" pex would be a little more than double with the same.

The Univeral Hydronics Formula: Btus = (gpm X 500) / delta T.

cnmdesign

Thanks, from what I read, pex al pex delivers more BTUs to the outside of the tube than regular pex-B. Would that change the delta T no matter what the speed. What I was kind of getting at is, if a zone came up short on a 20 dT with pex-B could you use p-a-p to make up the shortage?

cnmdesign

When everything is working to specs, what provides the bigger savings? The condensing or the modulation and what is the (about) percentage break down if possible?

cnmdesign

Solid_Fuel_Man said:

Caleffi is very high quality from what I've used.



That's not to say there are not other high quality products out there, but if it says Caleffi in the box it's pretty much a guarantee.



Their Z-one zone valves and diverting valves are a personal favorite.

Getting the 4 n 1 hydraulic separator and zone valves. Any recommendations on the valves for my system? can you provide the part number so I get it right? Thanks

cnmdesign

Getting the Caleffi QuickSetter Balancing valve with flow meter & temperature gauge. Does each zone need to be balanced or just the circuits in each zone or both? Thanks