Questions about Split Loop type system with HWBB

newtonkid88

1) What are the balancing valves? Are they just zone valves? Are they required if this whole loop is 1 zone?

2) Can the supply/return trunk be 1” hePex and the circuit be 3/4” hePex?

Using SlantFin copper fintube.

Any literature on these types of systems? I cant find much on google or youtube other than they exist to help with the problems of a series circuit.

Is this basically a manifold type system with only 2 legs?

Jamie Hall

Not an uncommon way to pipe a system, though you do have to be aware that the last radiation in the loop won't put out as much heat as the first will, per foot of radiation -- so you have to be a bit careful about getting the right lengths of radiation in each space to get the heat even.

If you have two zones with two thermostats, you would have two zone valves -- which are not the same as balancing valves. If you have one zone, with one thermostat, then the balancing valves are there to get the heating even (or as desired) between the two loops. Otherwise, unless the loops are genuinely identical, which is unlikely, one will get more heat than the other.

That help?

hot_rod

The balance valves adjust the flow rate to the two different zones, or loops. There are many types of balance valves, and price ranges. You may or may not need them depending on the size of the two loops. A couple pressure independent type with a delta P ECM circulator are simple and effective. They adjust flow to the exact requirement and allow the circ pump to also modulate.

First you need to determine how many and what size fin tube sections are required. Do a heat load calc first.www.slantfin.com has a useful calculator.
Then you can size heat emitters and pipe. 1" pex can handle 75,000 BTU/hr, designed around a 20 degree temperature drop.

bburd

This looks like an older diagram. Current practice is to pump away from the expansion tank, which generally means away from the boiler. The pump should be on the supply trunk instead of the return. This will minimize air problems in the system.

Big Ed_4

The split system was used for larger baseboard system one zone systems over 60 feet . Zoning was a better idea ..

hot_rod

bburd said:

This looks like an older diagram. Current practice is to pump away from the expansion tank, which generally means away from the boiler. The pump should be on the supply trunk instead of the return. This will minimize air problems in the system.

A conceptual drawing hopefully. It's not a great idea to bullhead tees like that either.

I don't see an expansion tank noted? It could be placed on the suction side of the circ, even with it pumping towards the boiler, and be just fine, happily pumping away.

newtonkid88

Thanks everybody. 

Yes I believe it’s just a conceptual drawing. I just took a screenshot of this video from youtube.
https://m.youtube.com/watch?v=PfpfI7Z4YC4

hot_rod

Here is an example of why you might split a long loop.
Notice it takes 22' of fin tube at the end of the loop to get the same 10,000 btu/hr as the 17' at the beginning. The temperature drop of 20F reduces output at the tail end. Pressure drop also goes down in the split loop.

newtonkid88

hot_rod said:

Here is an example of why you might split a long loop. Notice it takes 22' of fin tube at the end of the loop to get the same 10,000 btu/hr as the 17' at the beginning. The temperature drop of 20F reduces output at the tail end. Pressure drop also goes down in the split loop.

Since there are 5 radiators, one loop would have 3 and the other loop would have 2. Because of the unequal loops, would balancing valves be required?

What would be the last straw that decided you’d need to split the loop? Is it the 20F drop? Is it the overall length of the loop?

My perimeter of my floorplan is a rectangle of 20’ x 35’. Staircase dead center. Living room, kitchen, dining, bathroom. Pretty much almost wide open floorplan. I’ve only got room for 49’ of overall baseboard element. 5 separated sections of element.

hot_rod

Perhaps a better option would be to split it with zone valves, and have two separate thermostats. No balance valve required.

I'd still do a heat load calc, see how the heat emitters match up. More importantly how the boiler size matches the heat load. if it is oversized splitting to two zones could worsen short cycling.

Do you have radiators or copper fin tube baseboard? Is this a new build/ remodel or existing system? 700 square feet total building size? Staircase to upper level? Or basement?

If you are trying to balance some rooms you can do that by adjusting the dampers on fin tube, to some extent. Close down hot rooms cooler rooms get more heat output.

EdTheHeaterMan

newtonkid88 said:

1) What are the balancing valves? Are they just zone valves? Are they required if this whole loop is 1 zone?

2) Can the supply/return trunk be 1” hePex and the circuit be 3/4” hePex?

Using SlantFin copper fintube.

Any literature on these types of systems? I cant find much on google or youtube other than they exist to help with the problems of a series circuit.

Is this basically a manifold type system with only 2 legs?

You may find this information helpful

http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf

And the balancing valves are not zone valves, they can be simple ball valves. You may not actually need them for balancing if the two loops are about the same size (pressure drop), but you should install them for no other reason but to purge air from each loop individually.

1" trunk to a pair of 3/4" loops should be fine as long as there is less than 60 ft of aluminum fin element per loop.

newtonkid88

hot_rod said:

This is a remodel. 700 sqft each floor. 2-story colonial. I’m the one with the other recent post about monoflo.

The existing monoflo was for the whole house, single zone. I want a separate zone for each floor. My plan is to keep the monoflo for the 2nd floor, where the bedrooms are. Remove the 1st floor monoflo risers but connect the Ts with a pipe to maintain flow.

Going to use slant fin copper tube. HePex pipe 3/4” for everything except the existing black steel monoflo loop. The old black steel is 1” loop and 1/2” risers.

I did download the old computer program that lets you calculate a series circuit.

The only reason I’m okay with having a series loop on the 1st floor is that it’s an open floor plan. There are no partition walls other than a staircase in the middle…. Like a rectangle donut. 

The boiler is a Buderus G115ws4

hot_rod

Is it possible to redo the up and down to a multi zone/ series piping? Seems the combination of mono-flo and series piping may get complicated and harder to control properly.

So 1400 sq feet of home, what was the total load? I'd guess under 50,000 btu/hr, maybe into the 35,000 range. Sounds like you have a 100,000 boiler?

EdTheHeaterMan

I believe this diagram will work well for @newtonkid88. Based on all the information in both of his discussions, this is the simple, easiest piping diagram. I realize that not all the baseboards are represented in this diagram, but the idea is sound for the application. Place a 1/2" pipe from the supply to the return of each first floor, disconnected radiator, in order to keep the second floor loop in proper balance with the original design. Then use 3/4" PEX to make a series loop for the existing first floor. Add balancing valves as shown and add one purge valve to remove air from the first floor loop. ( continue to remove air from second floor radiators in the usual manor of the original design). A bleeder may be needed on the 1/2" jumper pipe(s)
Existing

Proposed

All piping is done in the basement, but you man need to remove the old 1/2" piping to the first floor baseboards, since you will be connecting more than 25 ft of element on that loop. No 1/2" piping can be in that first floor series loop since 1/2" will restrict the amount of heat that can pass thru that size pipe. All the pipe must be a minimum of 3/4" to accommodate up to 66'+ total element
I hope this is helpful.

Mr.ED

newtonkid88

hot_rod said:

Is it possible to redo the up and down to a multi zone/ series piping? Seems the combination of mono-flo and series piping may get complicated and harder to control properly.

So 1400 sq feet of home, what was the total load? I'd guess under 50,000 btu/hr, maybe into the 35,000 range. Sounds like you have a 100,000 boiler?

I do have a new addition of about 100 sqft each floor (mudroom & bathroom) that i'm trying to heat. The original sqft was 1200. It is now 1400.

The original 1200 sqft had about 96' of bb radiator and if I remember correctly, it was the standard fin-tube, not the large fins. That system worked with the G115 WS4 and Grundfos UPS15-58FC on the MED setting.

I do plan on having the 1st floor and 2nd floor on 2 separate pumps.

My Viessmann VIE7638988 indirect 42 gallon hot water heater is also zoned from this boiler.

newtonkid88

EdTheHeaterMan said:

That's amazing, Ed thank you.

My current set up has the pump on the return side of the boiler, pumping into the boiler. I would also like to have a separate pump for the series line. Because the monoflo pump is also zoned for my indirect water heater. I think that's too much work for the pump to add another zone (series loop).

Any reason why to install 1/2" copper or pex rather than 3/4" pex between the abandoned Ts? It is my understanding that the old 1/2" black steel that I removed is pretty much the same ID as 3/4" pex.

newtonkid88

OOPS

EdTheHeaterMan

The pump will do just fine. If you have the pump that came with the boiler, like a Taco 007, that has the ability to pump more that 10 gallon per minute (100,000 BTU) at a head pressure of 7 Ft. That is more than you need. Zone valves will be a better choice. If you read the text http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf from earlier (see page 7) you can see that separate circulators require separate flow check valves and controls. If you have an indirect already, then you must have at least 2 zone valves already (if you have only one circulator pump as indicated by your previous postings)

newtonkid88

EdTheHeaterMan said:

Thanks for the link. I just read about half of it just now. I will finish it later tonight. So far, i feel like I can design my own system from reading that, very informative.

Ive gotta admit though that it is ALOT of information for me to take in all at once

newtonkid88

EdTheHeaterMan said:

The pump will do just fine. If you have the pump that came with the boiler, like a Taco 007, that has the ability to pump more that 10 gallon per minute (100,000 BTU) at a head pressure of 7 Ft. That is more than you need. Zone valves will be a better choice. If you read the text http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf from earlier (see page 7) you can see that separate circulators require separate flow check valves and controls. If you have an indirect already, then you must have at least 2 zone valves already (if you have only one circulator pump as indicated by your previous postings)

So I finished reading… alot of the 2nd half goes right over my head even though I did understand a good amount of the 1st half.

Are you saying my single pump is okay for 3 zone valves: 1st floor series, 2nd floor monoflo, and indirect water heater?

Why do you recommend 1/2” copper/pex as opposed to 3/4” pex for the “jumpers” between the abandoned tees?

EdTheHeaterMan

Yes a single pump is fine for 3 zone valves.

Jumper Pipe: Only because the Tee fitting is probably 1/2" branch. But there is no problem going larger. 1/2" is minimum. It is important to get the air out of the jumper pipe.
You can place one of these tee fittings on the jumper pipe https://www.supplyhouse.com/Elkhart-59220-1-x-1-8-x-1-CxFxC-Baseboard-Tee-Lead-Free?_br_psugg_q=baseboard+tee
With a manual air vent like this.
https://www.supplyhouse.com/Matco-Norca-CK-100-Coin-Key-Air-Valve-Nickel-Plated

newtonkid88

EdTheHeaterMan said:

Only because the Tee fitting is probably 1/2" branch. But there is no problem going larger. 1/2" is minimum.

Thanks.  Just curious because the original black iron 1/2” pipe’s ID is larger than 1/2” pex. The 3/4” pex is very similar ID to the 1/2” black steel.

I ask about the single pump on 3 zones because I was concerned that the pump would have no downtime. Lead to quicker failure? The link you gave me stated more on/off cycles are not good.

EdTheHeaterMan

On/off cycles are not a real problem for your Grundfos pump. There is a tiny inrush of current on the capacitor start motor, but that pump should last for years. Never really thought about pump motor failure related to the number of zone valves. They are inexpensive enough if you want to have a spare. I'm thinking about looking on eBay or craigslist for a deal rather than paying full price from a wholesale supply company.

I have worked on system with 6 zones on one pump. I like to use 2 pumps if there are over 6 zones. There are other issues when pumping enough for 6 zones... all open at once and also handling the smallest zone with all the other zones closed. That kind of pump exists, but you don't need to worry about that with your set up. The Grundfos pump you have will work nicely with only one zone open or all three zones open. That pump is well suited for you proposed piping design.

hot_rod

I’m curious as to why you wan to keep the mono-flo system? If you are going with a traditional series system on one floor, why not do the whole system the same.
The diverter tee system was designed or should have been around certain size emitters, pressure and temperature drop. Adding short jumpers will change the dynamics. Sure it may work but you still have a high pressure drop, hard to purge system to wrestle with,

Two short, separate zones with fin tube could be circulated with about 27 W with a delta P ECM circulator that would modulate to the exact flow requirements.

mattmia2

I would probably go with home run or remove one side of each emitter from the existing main and add another main for supply or return rather than series. They did monoflow because it equalizes supply temps better than a series loop.

hot_rod

A couple more spins on what Ed mentioned. It really depends on what you objective is. If you want individual control, or control in some areas a manual or TRV valve could be included.

TRV thermostatic radiator valves are
non electric valves, easy to retro fit in many cases.

The room by room heat load and baseboard sizing depends a lot on how you pipe and the temperature drop(s)

Panel rads are another option, they can run at lower SWT, so adding them at the end of the mono-flo loop could be an option.

I prefer the heat from a panel rad as it is radiant and convection, they can ramp up and down quickly, nice in bedrooms that you might want to set back.

newtonkid88

hot_rod said:

I’m curious as to why you wan to keep the mono-flo system? If you are going with a traditional series system on one floor, why not do the whole system the same.
The diverter tee system was designed or should have been around certain size emitters, pressure and temperature drop. Adding short jumpers will change the dynamics. Sure it may work but you still have a high pressure drop, hard to purge system to wrestle with,

Two short, separate zones with fin tube could be circulated with about 27 W with a delta P ECM circulator that would modulate to the exact flow requirements.

I wanted to save the monoflo for the simple fact that the loop is already there.... to save money. I have since realized that in real life practice, it is going to be a big headache trying to plumb the new lines from the existing loop, especially with a new addition. I won't be able to avoid the ups and downs in the branches going to the heating elements.

I spent a good portion of today reading alot online and drawing up these new layouts.

2nd floor designed with a Reverse-Return layout. Can this also be done with a manifold?

1st floor still with a Series layout to save money. I used the "Series Baseboard Simulator" program to estimate the BTUs based on allowable baseboard locations.

Would I need to install bleader screws at each radiator with these layouts?

newtonkid88

mattmia2 said:

I would probably go with home run or remove one side of each emitter from the existing main and add another main for supply or return rather than series. They did monoflow because it equalizes supply temps better than a series loop.

Is my new 2nd floor drawing considered a "homerun" type? The reverse-return?

hot_rod

Home run is where every piece of baseboard gets a supply and return, usually from a centrally located manifold. 1/2” Pex is usually adequate. It may be your best option, and would give you the ability to zone in the future

Download Idronics #4 and 5 to show various zoning options

mattmia2

there is another option where you disconnect the supply from each emitter from the existing main and plug the main and run 2 new supply mains or bring each floor's supply to a manifold, that way you can split it and make it parallel and avoid repiping half of it. You would probably want a balancing valve on each emitter.

newtonkid88

EdTheHeaterMan said:

Do you think my reverse-return diagram is okay for the 2nd floor?

newtonkid88

hot_rod said:

Home run is where every piece of baseboard gets a supply and return, usually from a centrally located manifold. 1/2” Pex is usually adequate. It may be your best option, and would give you the ability to zone in the future

Download Idronics #4 and 5 to show various zoning options

I scanned #4 real quick. Will read it later.

If I understand correctly, my reverse-return drawing is similar to a manifold system. My main supply and return are basically the manifolds, but stretched out around the basement? But it would be more difficult if I wanted to zone the reverse-return later? 

hot_rod

Reverse return is really more for large spread out commercial type systems. With your small perimeter it would be overkill, and it takes and additional pipe run, more cost.

Fig. 4-7 shows a home run to a central manifold. With a two story home you could have two manifold locations, one for the lower level one for upstairs to cut down on pex runs.
1/2 sometimes even 3/8 pex can be used if all the fin tube need 1 gpm or less, 1/2' pex is fine.

Home run pros and cons, no fittings in the walls, easy to zone now or later, low pumping requirement, all baseboards get exact same supply temperature, easy DIY project.
Cons, it does take a bit of tubing runs.

newtonkid88

hot_rod said:

Reverse return is really more for large spread out commercial type systems. With your small perimeter it would be overkill, and it takes and additional pipe run, more cost.

Fig. 4-7 shows a home run to a central manifold. With a two story home you could have two manifold locations, one for the lower level one for upstairs to cut down on pex runs.
1/2 sometimes even 3/8 pex can be used if all the fin tube need 1 gpm or less, 1/2' pex is fine.

Home run pros and cons, no fittings in the walls, easy to zone now or later, low pumping requirement, all baseboards get exact same supply temperature, easy DIY project.
Cons, it does take a bit of tubing runs.

I drew up a manifold system for the 2nd floor. It's really messy, sorry lol.

So, 1" pex for the mains, and 1/2" for the branches to the baseboards? Should I use 3/4" for the longer runs where the baseboards are further away from the manifolds?

I have the supply and return manifolds on the top (north) of the drawing. Should I put the 1st floor on the bottom side of the drawing (south). Or keep all 4 manifolds on the same wall? Should the manifolds be centrally located in the house to all the baseboards?

I could only find metal manifolds that are for radiant floor heating. Are those the same as what I need for my baseboard setup?

hot_rod

1" pex from the boiler to the manifold is plenty, 1/2" to all the fin tube from the manifold.
Yes centrally locate the manifold, the main floor may be near the boiler, or mid room if it shortens loops.. Your largest element, 15' is 9100 BTU/hr, just under 1 gpm, easily handled by 1/2"

In some cases a 2nd floor manifold is located in a closet somewhere to get it more central and shorten all the runs.

Yes, radiant manifolds, composite, stainless steel, or brass. Caleffi, maybe others build inverted manifolds, branches go up instead of down like radiant floors typically are.

Here is an example where an inverted manifold would eliminate all those curls to change tube direction. it looks messy and adds another 50' of tube or more?

Manifolds can also be mounted horizontally, up against the floor joist for example, shown here.

newtonkid88

hot_rod said:

1" pex from the boiler to the manifold is plenty, 1/2" to all the fin tube from the manifold.
Yes centrally locate the manifold, the main floor may be near the boiler, or mid room if it shortens loops.. Your largest element, 15' is 9100 BTU/hr, just under 1 gpm, easily handled by 1/2"

In some cases a 2nd floor manifold is located in a closet somewhere to get it more central and shorten all the runs.

Yes, radiant manifolds, composite, stainless steel, or brass. Caleffi, maybe others build inverted manifolds, branches go up instead of down like radiant floors typically are.

Here is an example where an inverted manifold would eliminate all those curls to change tube direction. it looks messy and adds another 50' of tube or more?

Manifolds can also be mounted horizontally, up against the floor joist for example, shown here.

Would I need to change any of my existing equipment? Eg: air remover, valves, circulator?

Would I need bleeder vents at the element?

What are the effects of doing 3/4" hePex to each radiator?

Thank you

hot_rod

One spirovent or equal at the boiler, no need to have two. The pump would be better at the supply side of the boiler, directly after the expansion tank.
I prefer zone valves on the return, they work in either supply or return. One for the indirect, one for the manifold. Maybe one spare?

No on the bleeders.

No need for 3/4" it is much harder to work and at those low flow rates the velocity would be slow, possibly making air removal harder.
Most manifolds have bleeder valves and air vents on them. So purge one loop at a time, and let it rip.

You seem to have a bleeder ell fetish?

newtonkid88

hot_rod said:

One spirovent or equal at the boiler, no need to have two. The pump would be better at the supply side of the boiler, directly after the expansion tank.
I prefer zone valves on the return, they work in either supply or return. One for the indirect, one for the manifold. Maybe one spare?

No on the bleeders.

No need for 3/4" it is much harder to work and at those low flow rates the velocity would be slow, possibly making air removal harder.
Most manifolds have bleeder valves and air vents on them. So purge one loop at a time, and let it rip.

You seem to have a bleeder ell fetish?

Haha everything I know about heating systems comes from my monoflo, where apparently, bleeder valves are very important.

newtonkid88

hot_rod said:

1" pex from the boiler to the manifold is plenty, 1/2" to all the fin tube from the manifold. Yes centrally locate the manifold, the main floor may be near the boiler, or mid room if it shortens loops.. Your largest element, 15' is 9100 BTU/hr, just under 1 gpm, easily handled by 1/2" In some cases a 2nd floor manifold is located in a closet somewhere to get it more central and shorten all the runs.

My dining room has 23’-24’ of heating element. Planned on using Slant Fin’s JUMBO element at 840 BTU/foot. Should that pipe be upsized to 3/4” from the manifold?

Some of the total runs will be close to 150’ of pipe equivalent (including elbows etc) to snake its way around joists and through walls to get to the addition. 

hot_rod

If you go to the PPI plastic pipe institute website, the have a free calculator to check loop lengths, tube size, pressure drop, etc

You input btu requirement, loop length tube size

most of the radiant tube manufacturers have this info available at their website also 

LoopCAD has a free trial of their software to give you the info and develop a layout.

Your big loop is about 2 gpm no harm in going to 3/4 the manifolds will accept 3/8- 3/4 on the branches.

All these questions can be calculated to get exact answers, if you want

Idronics 16 steps you through the process of calculating all this with examples also.

newtonkid88

hot_rod said:

If you go to the PPI plastic pipe institute website, the have a free calculator to check loop lengths, tube size, pressure drop, etc

You input btu requirement, loop length tube size

most of the radiant tube manufacturers have this info available at their website also 

LoopCAD has a free trial of their software to give you the info and develop a layout.

Your big loop is about 2 gpm no harm in going to 3/4 the manifolds will accept 3/8- 3/4 on the branches.

All these questions can be calculated to get exact answers, if you want

Idronics 16 steps you through the process of calculating all this with examples also.

I have seen the chart in the Zoning manual from B&G and it was right on the fence for the 1/2”. Thats how I even knew to ask to confirm. I will take at look at the PPI website.

Can I have 2 manifolds in series? To bring it in my addition’s crawlspace to have shorter branches up to the addition?