Hydronic Hell latest

Alaskan

Two years ago I posted a query for help with my 20 yo quonset heating system http://forum.heatinghelp.com/discussion/147971/hydronic-hell#latest. I received great response, unfortunately, my Father-in-law passed away shortly after that and we went to VA for the funeral. The two week visit turned into 5 months before we returned and we've been playing catch up the last year and a half.

This summer I started to revisit my heating situation and after talking with a local heating guy who spoke with the Grundfos rep recommended that I first start by replacing my 20+ yo 20-42f two speed pump with two 26-99 multispeed bronze pumps. They said this should help (not resolve) the two 1000' lengths that single pump was pushing by 1) creating two separate zones, 2) pump capability to push more water through zone, and 3) reduce the rust in my lines. They were surprised that the 20-42 cast iron pump lasted this long in an open system.

I'm about to install the pumps and am unsure what type of relay's I should install so that I can use thermostats to trigger the pumps. The 20-42 presently uses a Penn A19BBC-2 which is mounted right next to the utility area and tends to be the warmest place in the building. I was told by the guy who built this place that he believes when he built the building , he put one of the loops in the 25'x30' living area and the other loop spread out more in the 50'x30' shop area. My thought is to install relay's that allow me to more strategically place the thermostats so that I have more accurate reading of actual temps.

My big picture look is that this system has been working (not very efficiently) for over 20 years. PB tubing is questionable stuff but has worked this long. It may not handle the increased pressure but I won't know if I don't try. If I improve the efficiency of the heating system any, that's good. And if this does work, I'm going to see about installing reversers to additionally improve the efficiency. I emailed the author of that article HotRod posted but never received a response. If this does show improvement, another option we hope to do is to dig around foundation on at least the long sides and put blueboard insulation down 2' and out 2' kind of like an "L".

I'll be primarily using 3/4 PEX to perform all plumbing. Hopefully that will also remove some of the 90's in the current system.

To answer some of the questions from my original thread:

...don't know what insulation is under building. The builder doesn't remember and there isn't an easy way to check as the slab is pretty well sealed up.

...not feasible to install new lines nor to break up slab to break up existing loops. To accomplish either, so much would have to be torn up/disassembled that it's not financially viable for this type building. Also, breaking up the slab just to continue using PB tubing doesn't make sense to me.

...would love to do a heat loss calc, building is pretty simple above ground (metal building with 4" sprayed urethane) it's the below ground I have no clue on.

My questions (some recapped from above):

Type of relays to use with 26-99?

What speed is best for the pumps? I'll start with low, but I just don't know where to go from there or if I should go up...

The existing system is shown, I plan on cutting off the copper before the pump and cutting off the PB right after the fitting, then using PEX. Do you forsee any problems with using a Watts LFP-705 to connect the PB to PEX or should I not disturb the PB and use present fittings?

I'll be installiing a 2x12 behind the pumps, what is the best way to mount pumps to vertically to the board as I'll be using PEX before and after?

I appreciate any/all advice you can give.

Thanks,
Paul

Rich_49

Is this 2 loops @ 1000' each or 2 loops totaling 1000' ?
Did the Grundfos guy at least tell you to get that pump horizontal instead of vertical? What temp water will you be moving and what is the required flow in GPM ?

hot_rod

Are you going to continue to use it as an open system? If so you might want a stainless circ pump or pumps. If the PB fittings are not leaking, just reconnect to the copper, the tube should hold whatever city or well pressure you have.

There is only so much you can do with 1000 foot loops, a high head circ is the first step. A flow reverser helps also, just depends on what you consider "good enough"

Two pumps?

Any of the switching relay controls will work, Caleffi, Argo, Taco all have products, then add a couple 24V wall stats.

Zman

I messed around with this in the calculator. I don't have he exact curve for the existing circ but if it was replaced by the 15-42 it looks like you are moving about .65 GPM. Replacing it with a 26-99 gets you .97 GPM per loop. The interesting thing is that putting a 26-99 on each loop still gives you .97 per loop. So the extra circ will not give you any more flow. You are just out there on the ragged edge of the curve. The 26-99 will probably last longer if you only install one as the extra flow will help keep it cool.
It also looks like the delta t between the supply and return in the loops will be 86 degrees. Depending on how the tubing is placed,this will create some real hot and cold spots.
If you put in an automatic flow reversing valve, it will help mitigate the problem.
I would not worry much about the polybutyle. The 13psi the circ adds should not be a problem. I would be more concerned with the high temps.
All for now...
Carl

hot_rod

Like Carl indicated, you can flow that long loop, but it's that huge delta T that becomes the challenge. Upping the supply helps get heat energy to the middle of the loop, but the beginning will be hot.

If you decide to go that far, the reverser really helps sneak up to the middle from both ends.

Maybe for a shop, not a big deal?

Alaskan

Thank you for the replies. I'll try to answer in order.

Rich, The system is 2 1000' loops. The old pump has worked in that position for over 20 years. The new 26-99's will be installed vertically with the motors being level horizontally according to mfg instr. Since it's an open system, the hot water temps can't get too high since we use it at spigots too. Haven't measured exact temps lately.

Hot Rod, It will stay an open system because closing it would require an exchanger and wouldn't that make a horrible system even worse? A flow reverser is in the plans, but I want to see how this works first before investing more. Aren't brass pumps accomplishing the same goals as stainless steel? I was told that using zone valves in an open system would cause them to fail rapidly and because of the length of the run, one pump on each run would accomplish the regulation and also be more efficient. From Zman's calc's it looks like it won't be any more efficient. Is there a way to only install one pump and monitor each loop? I first wanted to use zone valves, but kept coming across the warning about open systems causing early failure, or is that bunk?

Zman did you happen to run calc's on the 20-42? I'd be interested to know how much I will be improving the GPM?

One thing I'm happy exists...PEX. I'm fairly proficient with copper but PEX makes these changes so quick and easy.

Paul

hot_rod

Sure bronze, stainless, composite any will work.

Officially anything that touches potable water needs to be low lead. The Caleffi Z-one zone valves are approved and listed for potable water, with low lead brass bodies. Sure you can use zone valves on open systems, if they are listed for potable water.

I agree with Carl, no need to buy two expensive pumps, one pump, two ZVs if you want to zone.

However, if you do add a reverser, zone valves are usually one direction flow, at least flapper and plunger style. And again the reverser should be low lead.

If at all possible consider the reverser now, even with that smaller circ pump you could get much better performance.

The calc in this article are done with a 15-42 or 15-58 sized circ around a 50 delta T

Adding a nicely sized flat plate HX isn't going to cause that much of a pump penalty, it puts you into less expensive iron body circs, and eliminates that nasty legionella potential with stagnant water in those loops all summer season! I doubt many licensed plumbers would want their name or liability on an open system these days. You shouldn't either1

http://www.pmmag.com/articles/87331-the-long-way-around-br-john-siegenthaler-pe

Ironman

If you're gonna go the larger pump route, I'd use a ups26-150. That should get you over 2gpm @ 45' of head. It will bolt up the same.

Alaskan

I've been digesting what you said Bob and now am unsure what to do. I have already purchased two Grundfos 26-99 multispeed bronze pumps. I'm not a plumber, but do know how to plumb within certain limitations. Guess you'd say I'm a typical rural Alaskan guy who does most of his own work because of location and/or expense. I already paid for the local plumber to come out and give me their recommendation. The two 1000' loops really dumbfounded them. So after paying them for their time, I'm on my own. We're getting colder here so I need to do something now. Based on what all have said, I have these questions:

Wouldn't installing an HX result in worse heat transfer than I already have?

Looking at zone valves, I'm having difficulty locating ones that will work in an open system and are stainless/bronze low lead. If you have a model that you can recommend to me, I'd appreciate it. Then I can explore using one pump. If this does work, I still have to figure out how to wire the system with the bock hot water heater so that the zone valves open before the pumps are energized or so I understand from a previous thread on here.

If the above doesn't work, can I install the 26-99 pump on each line without creating greater problems? That would give me greater control over heating the part of the building that we need heated the most. I still want to explore the reversers, but need to get this step done now.

I started out with a plan based on knowledgeable local plumbers advice and you guys kind of shot holes in it. Now I'm really brain dead...

Ironman

If you connect both pumps together in series (flange to flange), the dynamic head output of the pumps is doubled but the gpm remains the same. If you connect them in parallel (side by side), the gpm is doubled but dynamic head remains the same.

Since the major issue that you're facing is too much head, due to the loop length, I would connect them in series.

hot_rod

Alaskan said:

I've been digesting what you said Bob and now am unsure what to do. I have already purchased two Grundfos 26-99 multispeed bronze pumps. I'm not a plumber, but do know how to plumb within certain limitations. Guess you'd say I'm a typical rural Alaskan guy who does most of his own work because of location and/or expense. I already paid for the local plumber to come out and give me their recommendation. The two 1000' loops really dumbfounded them. So after paying them for their time, I'm on my own. We're getting colder here so I need to do something now. Based on what all have said, I have these questions:

Wouldn't installing an HX result in worse heat transfer than I already have?

Looking at zone valves, I'm having difficulty locating ones that will work in an open system and are stainless/bronze low lead. If you have a model that you can recommend to me, I'd appreciate it. Then I can explore using one pump. If this does work, I still have to figure out how to wire the system with the bock hot water heater so that the zone valves open before the pumps are energized or so I understand from a previous thread on here.

If the above doesn't work, can I install the 26-99 pump on each line without creating greater problems? That would give me greater control over heating the part of the building that we need heated the most. I still want to explore the reversers, but need to get this step done now.

I started out with a plan based on knowledgeable local plumbers advice and you guys kind of shot holes in it. Now I'm really brain dead...

The easiest and least expensive path would be a single pump and two zone calves.

I'd suggest the Caleffi Z207533, a 3/4 sweat low lead body with a 35 psi shut off. It can shut off against the high head circ
Add the Z111000 24V actuator. This has an end switch that will start the pump only when the valve opens, wired through a relay

Yes the HX will cost some performance.

Really the question is how much better are you trying to make this, and how much to spend.

A good first step is the high head circ, this alone will increase output.

If you are trying to maximize comfort, the reverser evens out the slab temperature, the high head circ pump alone will not.

So you have a choice of good, better, best, options.

If you want to help the contractors better understand what happens with1000 foot loops, just send them the link to that article mentioned above,really no mystery to the problem, or magic to a solution.

Zman

To answer your original question, the easiest way to control the circulators is with a pump relay like the taco SR502-4. It makes the wiring really simple.
I do not have the specs for the existing circ my guess is that you were pumping about .6gpm and you will go to 1 gpm.
If you were trying to get the max flow out of the parts you have on hand, you could use the 26-99's in series (one after another) with 12" of pipe in between and use zone valves. Yes, it is hard to find zone valves that meet the new drinking water codes. You have an open heating system. Worrying about that is kind of like making sure you don't "J" walk as you are leaving the murder scene. A misdemeanor at worst.

SWEI

hot rod said:

If you are trying to maximize comfort, the reverser evens out the slab temperature, the high head circ pump alone will not.

^^^^ This.

Alaskan

Thanks Bob Rohr, Bob Boan, & Zman! Don't know that I would have progressed thus far without your help and all the others who have contributed.

I've been checking the closest box store and plumbing shops (all 30 miles away). The zone valves I've found have all stated "for closed systems only". Haven't found Caleffi local so far.

Since my system seems to be a **** system and none of the schematics relate to it, can someone tell me how to wire the Taco SR502-4 to the pumps (in series) and then to the zone valves? I see zone 1 and zone 2 circulator connectors, but don't see where the zone valves connect, nor how to start up pumps for either zone... Will both pumps start simultaneously or is there a micro delay? Will the zones open and then pumps start? Also, with my system, can I use the zone 2 priority on the more used living area or won't it matter?

Plans thus far...

Step 1

3/4" copper from Bock hot water heater to first 26-99 then 12" length of 3/4 copper to second 26-99. Using PEX from there to T and then to each Zone Valve which is connected via PEX to PB.

Confirm system heating zones separately and observe for period of time.

Step 2

Install motorized 4 way reverser with timer on supply line before T to Zone valves and on return line after T joining lines. Exact make/model yet to be determined.

One last thing, on my system, I don't have a condenser valve, or air separator as shown on the below diagram Mark posted in my original thread. Are these things that I need to incorporate at some time?

And last but not least...A huge grateful thank you again to all who have participated in this thread. Your help is so appreciated.

Paul

Ironman

Connect the zones valves' end switches in parallel to the thermostat ("T&T"or "R&W") terminals on the zone control. You only need and SR 501-4 single zone control. If you already have the SR 502, then you could connect each zone valve end switch to the separate "TT or "RW" terminals and jumper the high voltage pump terminals together from both zones. You only need to do the hot terminals, the neutrals are internally connected.

If you turn on the priority switch, the other zone will be locked out for 30 or 60 minutes when that zone is called.

Alaskan

Thank you Bob for explaining the wiring. I bought the 502-4 because that's what Zman recommended above. Still have yet to find zone valves that don't state "for closed systems only". Guess my question is what is the difference between a closed and open system zone valve? Is it a case of the metals used in closed systems not being safe for drinking water or is it something else?

Thanks again,

Paul

SWEI

Caleffi and Belimo both sell zone valves that are OK for open systems.

hot_rod

Alaskan said:

Thank you Bob for explaining the wiring. I bought the 502-4 because that's what Zman recommended above. Still have yet to find zone valves that don't state "for closed systems only". Guess my question is what is the difference between a closed and open system zone valve? Is it a case of the metals used in closed systems not being safe for drinking water or is it something else?

Thanks again,

Paul

Correct,any valve that comes in contact with potable water must be a listed low lead valve.

Many of the Caleffi Z- one and other valves have the IAMPO R&T Low Lead shield and generally any low lead valve will have a LF label.

Alaskan

Thanks SWEI & Bob.

Well, I've checked with all the local plumbing shops. None of them have any low lead zone valves much less Caleffi or Belimo. Checking around online, the Caleffi isn't very prevalent. I've found the valve without the control head on Amazon. The few places I found that have them either don't ship to Alaska, or the shipping charges almost equal the price of the valve. Any ideas?

One other thought I'd like to explore... Was talking with another friend who is much like myself, except is truly an Alaskan rural fabricator (read Redneck Engineer extrodinare for you lower 48 types) and he suggested I keep the Bock on the heating loops making it a closed type system and instead install another oil hot water heater or on demand unit for the household hot water. That appeals to me after reading up on Legionella bacteria. What would it take for me to convert? Right now the hot water off my Bock, T's with one going to household and the other going to heat with its return to the Bock. If this is viable, any suggestions on type heater (on demand or traditional). I'm limited to oil as other alternative are cost prohibitive or not available.

Oh yeah, and I need to do this ASAP... LOL

hot_rod

That is not a bad idea dedicating the tank just to the radiant.

Here is an idea I have wanted to try, just put the two pumps in pumping towards each other. Run one for 30 minutes,switch off, then power the other.

A simple double throw RIB really could power that.

I would not put those two pumps in series, you will have some crazy high velocities. If you circulate from both ends one pump would cover it. Again, making the best out of a bad installation.

Alaskan

Bob, I've been reconsidering the serial installation of the pumps, so am glad you also are questioning it.

Now on the above diagram...

I understand the air sep, but don't know why the expansion tank is there? Wouldn't the pressure relief valve on the Bock serve the same purpose or is it a case of the tank being a cleaner install and not having water blow out all the time?

I would still need to install zone valves if I desire to separately heat one of the zones?

Are 26-99's engineered to be open when not in use? If so, I wonder if the 20-42 I presently have allows water to flow through? If so, I bet my hot water is flowing through the system year round...

Does it matter if water returns to the Bock via the feed for return?

Still need to determine what type of second heater to use. Looked oil on demand heater and they run approx $2500...ouch! I'm wondering how much more fuel I will use with a second heater?

I'll chew on this some more, but those are my initial thoughts.

Thanks!!!!

Paul

hot_rod

First you need to decide if you are going with an open combo system, or a dedicated water heater for the radiant. I much prefer a dedicated heater to a combo radiant/ DHW system

Then decide if you want to split into two zones, if so my opposing pumps idea will not work with directional flow zone valves.

Splitting the zones with flow reversal will be a bit more complicated also.

If you use the Bock as a dedicated heater for the radiant it will be a closed pressurized system and as such it will need an expansion tank.

With a pumped flow the tank will be mixed all the time, so flow direction is not a big deal.

So focus in on which system you want to go with and the details can be worked out.

hot_rod

Here is another simpler reverser idea. It may be easier and less expensive to find 3 way valves instead of building a 4 way reverser and drive motor. I used one of these to load and unload a 500 gallon buffer tank connected to my wood fired boiler.

It's amazing what you can find on Amazon. And if you belong to their club shipping is free. Not sure if that applies to Alaska?

Ironman

hot rod said:

That is not a bad idea dedicating the tank just to the radiant.

Here is an idea I have wanted to try, just put the two pumps in pumping towards each other. Run one for 30 minutes,switch off, then power the other.

A simple double throw RIB really could power that.

I would not put those two pumps in series, you will have some crazy high velocities. If you circulate from both ends one pump would cover it. Again, making the best out of a bad installation.

@hot rod
I'm not following your reasoning about "crazy high velocities" if the pumps are placed in series. With the high head and low gpm of the long loops, how will the velocity be too high? Please help me here. What am I missing? I don't remember what size the tubing is - 3/4"? With PEX, wouldn't it still be in an acceptable range?

Also, on your second drawing: if each pump is placed outside of the picture frame, could not the motorized valve be eliminated?

It's late, so maybe the gears are turning a little slow for me.

hot_rod

I'm thinking the additional 26-99 in series will not add that much value if you use a reverser. Actually a small circ has been working on this system, so quite a bit of comfort would be realized by just reversing even with the small circ.



Two 26-99 in series, on speed 3 is just about 400W of power! At at a 2 or so gpm or so flow rate, nearly 60' of head.

I'd be tempted to just install one 26-99 on each loop, no reverser and give it a try. He already has the two pumps, and no reverser would need to be purchased or assembled, a cheap first step.

Alaskan

You guys are amazing!! Bob R. keep your ideas flowing. I love guys who think outside of the box. Bob B. my lines are 1/2" PB.

I believe reversing the lines will be the only way to make this system remotely functional, so that is my end goal.

Perhaps also a closed system, but I'm finding that option to be quite expensive, but will not put a price on health. We have some close friends who have had Pneumonia pass through their family several times. As a result of this thread and the research I've done on Legionella, I called them this week and told them of this. Hopefully they can examine their system to see if it is the cause. So if nothing else this has been awesome.

Yes, Bob, we are heavy users of Amazon Prime up here. Amazon is the primary online store we use because of their free shipping to Alaska.

I like the use of a 3-way, but don't understand in your diagram how it would cause reversing for both sides when the zones are split?

Your last paragraph above sounds like you are recommending me to install the pumps with out zone valves as I originally was going to? Just use the Taco 502-4 with the thmerostats to control each pump. Will this work just to get it running? I plan to use pex from the copper to pumps and then uses a pex to PB adapter. My thought is PEX will be easily modifiable to make future changes.

hot_rod

Yes, just put a pump on each loop just below where they tee off that manifold. No reverser, just upsizing the circulator pump.

Just replacing the small circ with a 26-99 adds quite a bit of performance.

Here it is with a 15-42 and a 26-99.

Steve Thompson (Taco)

Hey Hot Rod - you forgot to mention our 009 would do a high head/low flow job too...

hot_rod

Steve Thompson (Taco) said:

Hey Hot Rod - you forgot to mention our 009 would do a high head/low flow job too...

yes, the 009 and probably one of the B&G PL series would work. I think he already has purchased the 26-99, so I used those in the comparison.

SWEI

If the curves work out, the 009 will probably use a bit less power then the 26-99. I'd also consider a Grundfos 15-100 for this, depending on the flow requirements.

Alaskan

Any recommendations for the best way to vertically mount the 26-99 to the wall? I'm putting up 2x10 or 12 behind them to provide a solid foundation for support. Since there will be pex before and after, the piping won't help. So far I'm envisioning using Simpson steel straping to secure to 2x. There must be something better than that though? Steel strap reminds me of those who use duct tape to secure packages to their vehicles... lol

hot_rod

If you ask a pro, Unistrut is the correct answer.

A wood 2X2 could be used with a few 2 hole copper or electrical straps. With strut I use the rubber isolator clamps to limit noise and vibration being transferred to the buildings.

Those high head circs generally spin fast and do create a bit of noise. Isolate it with pipe insulation, then the strap around it, for a simple DIYer install.

Ironman

I've used the "L" brackets made for unistrut. I connected them to the flange bolts on the circ and screwed them to the wall. The brackets are the ones that are made to mount the unistrut to a floor or ceiling.
If vibration is an issue, then HR's method should be followed.

Kahndo

Hey Hot Rod, if those pumps don't work out for you, you might want to take a look at the Stratos Z as an alternative...
http://www.wilo-usa.com/wilo-usa-llc-home/tools-downloads/documentation/product-documentation/stratos-d/#.VhWUkflVhBc

Alaskan

Good Morning all, Just an update. Installed the 26-99 pumps using U-bolts on 3/4" plywood. I explored the unistrut but procuring what I needed was becoming time consuming and then using U-bolts popped into my mind and it was an instant fix. It looks clean and hopefully will prove to be just as strong. Did run into one slight problem... Was soldering on the male PEX fitting into the brass TACO flanges and all went well except for one. The joint failed testing, so I heated up and disassembled, cleaned, and redid. Failed again. Did the process once more, and it failed. I'm using a turbo torch so it wasn't a lack of heat. I'm heading into Anchorage today (4 hours away) and am hoping to just pick up some threaded 3/4" flanges. No clue why my others are fine and this one failed. Clean fittings, no moisture, clean flux, etc. To keep the flow as straight as possible I angled the pumps avoiding 90's keeping the pump shaft horizontal. Couldn't find male 3/4" to 1/2" PEX fitting locally so improvised with a section of PEX stepping down from 3/4 PEX to 1/2 PEX then to 1/2 PB. Bypassed the pump with missing flanges and hooked up the pump to the living area loop. Difference was quickly felt. Can definitely see the results of the more powerful pump...rust that had built up in the lines has been continuously coming out in the hot water.

Ironman

That Turbo torch may actually be getting the brass too hot. Brass doesn't conduct heat as quickly as copper so you have to heat it more slowly and evenly.
You can get threaded flanges too.

Alaskan

Well, the third time was the charm. It was either strike three you're out, or a hit. Cleaned the valve and fitting out and resoldered and this time it sealed fine (so far...lol, well I hope for good.) Next time I'm dealing with this type of bronze, I'm going with threaded.

Anyways, the system is back up and running. I won't see the REAL difference until we hit the below zero temps, but there are parts of this floor that are warm that never were before. Zman, thank you again for recommending the TACO SR502-4. That works like a charm with the living area set up as zone 2 and selecting zone 2 priority. Special thanks to Hot Rod and Ironman, and all others for your help and input!

Is this system perfect? No, and will never be... Is it significantly better than it was before? Yes. Can it be better? Yes. Next step is to start looking at reversing.

Again, a HUGE thanks to all that helped with your wisdom and advice!

Paul