Help with Great Room heating strategy and the wrong thermostat

kalex1114

schreib said:

Thanks for input Kalex.
Yes, I also pointed out that I am planning to at least remove the carpet just adjacent to windows to enable a bit more output near the biggest heat sink in the room, about 2 ft x 20 ft. I have a pair of 500watt baseboard heaters, yet to install, on same wall to augment the heat feed / loss from all the windows. FIRST, I must convince wife to ALLOW me to do that!
As to DHW: it must be that with particular settings I have there is no cycling at all on DHW. It satisfies quickly(minutes after shower) and never comes back to DHW while handling the SH. I don't understand your statement: "set the boiler output to 185f with offset of 10f from your 145". I could set DHW set point to 185 with offset of 10°F, which would mean it would allow DHW sensor to hit 195°F max before shutting down, no problem. but am confused why you mention 145. . . Must not understand something. I will verify my parameters, list them, and then we can continue this bit. . .
Meantime: Right now, my Squire hot water tank set point IS 125°F, not 145 or higher. My reasoning for choosing this is simple but perhaps naive. I have heard rumblings that higher temp may be necessary to prevent bacterial growth. . . some ref above, cannot recall. Any thoughts on that, why I should not keep it at 125°F for simple energy reasons?

I think we are talking about 2 different settings. You mentioned before that your setpoint for DHW is same as your Space heating setpoint of 145. Thats why i was commenting on.

THere are 2 setpoints at play for DHW.
Tank setpoint which is the internal temperature of the tank. That is set to 125f as per your settings.
Second set point is the DHW boiler setpoint. that is the setting that boiler supplies water at for your idirect tank coil. You mentioned before that its set to same as space heating side. Which based on your previous settings is 145. That is what i suggested you adjust. As raising the coil temp of the indirect tank will heat it up and satisfy it faster than 145f water.

To kill off Legionellae bacteria in the tank its recommended to set it to 140f not 125f. But that requires mixing valve which I don't believe you implemented yet, so 125f is fine without mixing valve.

Gordy

With the flir you can verify loop centers.

schreib

OK Yep.
I got those two setpoints confused. However I think your assumptions are correct—125° DHW set point, and 145° correlating boiler set point, while in DHW mode.
I will have to check into the Legionaire disease background, but I would guess that bacteria is not a problem in a closed system--it first appeared In an open air water tower situation in Wisconsin as I recall.

kalex1114

Your indirect is not in a closed system. Its coil is closed loop going via your boiler but actual tank gets filled from city water. That's where all the crap comes from not your boiler

Gordy

Legionella is in the tank , and piping of the domestic side of the system. It loves temperatures below 130 degrees. Keep tank temps above 135, and Mix down with a tempering valves.

schreib

OK, will do. thanks.

My reading from Mayo indicates Legionella bacteria is nearly entirely transmitted by BREATHING, ie via air. I guess the industry must have actual cases where it has been verified in closed systems too then.

schreib

NOTE to Kalex: Not on city water, mine is well fed, specialized backwashed filter system plus ultra fine, final filter to drinking water. By closed I mean all in closed things like piping or tanks. As I recall the first case of Legionaires disease was understood to have been generated by the water from a roof top cooling tower constantly in the outside air stream(to cool the water) and then, somehow being aspirated by humans after growing the bacteria there in large concentrations. My Mayo article is here:

https://www.mayoclinic.org/diseases-conditions/legionnaires-disease/symptoms-causes/syc-20351747

"The bacterium Legionella pneumophila is responsible for most cases of legionnaires' disease. Outdoors, legionella bacteria survive in soil and water, but rarely cause infections. Indoors, though, legionella bacteria can multiply in all kinds of water systems — hot tubs, air conditioners and mist sprayers in grocery store produce departments.

Although it's possible to contract legionnaires' disease from home plumbing systems, most outbreaks have occurred in large buildings, perhaps because complex systems allow the bacteria to grow and spread more easily."

kalex1114

Yes its true, small chance but eliminated by adjusting tank temp.

schreib

yep, got it.

Tim Potter

check in with ME (Mark Etherton) for input. I believe he is a survivor

Tim

schreib

sent him a PM. . . thanks Tim!

Gordy

If you shower breathing in the fine mist can be easily done. All it takes from there is lowered immunity from age, health issues, etc. many cases go undetected by the medical community upon an initial diagnoses.

hot_rod

Keeping tank temperature elevated is one good step to help prevent the potential. Be sure to add a good quality listed mixing valve at the tank.

The other concern is the bacteria lives in the bio film inside all the DHW piping. One of the current suggestions is to elevate the entire loop above 140 for a period of time to assure the bacteria is not able to take hold in the piping.

Still many buildings have dead end branches off the recirc loop that need to be addressed. Loop fittings and venturi fittings are being implemented to assure circulation thru the entire piping.

Strong chemical dosage is another method described in ASHRAE 188.

schreib

yes, got all that in readings I have done. thanks folks.

I am considering all of above. First line of defense is my yearly Chlorine shocking for well and entire home, 2nd is raising the temp , 3rd I may also buy a UV light for all incoming hot water(cost is about $100/yr for the light though). I already have mix down capability on all my shower heads but would appreciate input on a main mix down valve at the tank. Even though well insulated, maybe the Squire tank should be wrapped with water heater blanket also to make me "feel" better about storing hotter water!

One good thing about my whole system is that it is all PEX or plastic lined except faucets / valves; minimizing potential for any biofilm. Another good thing is I am on my own private well and I control what comes out of it. I may take samples to local water testing company and ask them to do spot checks for Legionella as a 2nd way to look at things. Maybe if I never see it after 3 yrs there is little concern. . . ???

schreib

unfortunately, I failed to provide for recirculation of my hot water when building the house. That would have been good for constant hot water at all faucets in addition to the obvious advantage of no dead spots. Too late now-- slab on grade.

hot_rod

schreib said:

unfortunately, I failed to provide for recirculation of my hot water when building the house. That would have been good for constant hot water at all faucets in addition to the obvious advantage of no dead spots. Too late now-- slab on grade.

There are a number of retro-fit recirculation systems available. they basically use the cold line for the loop and install a thermostatic mixer under the distant fixture. AquaMotion has a clever package available.

http://aquamotionhvac.com/news-alert-aquamotion-introduces-the-new-aqua-flash/


Of course if the pipes are in the slab, the recirculation loop becomes a heating loop also

A small POU electric heater under the sink is another option if it really bugs you.

schreib

Man, you guys are awesome. I will LOOK into that! Thanks!
For a while now I have planned on posting all my boiler parameters, so finally, here they are: see file

Gordy

I’m still more interested in dialing in your flow rates on the loops, then the boiler flow rates, then the parameters of the boiler.

Get the wrench back yet?

schreib

No actually, my highly effective contractor said he would mail me a "key" on Monday.-- wait mode.

I just received the FLIR today though, so this weekend I will be taking data! By the way, I figure that all the valves on the manifold are set by default to be wide open so I need only to screw them in to REDUCE flow, right?? If so, I will plan on leaving the loops where I want to maximize flow wide open / leave alone, while throttling the low priority or already fast response loops, right?

SuperJ

schreib said:

No actually, my highly effective contractor said he would mail me a "key" on Monday.-- wait mode.

I just received the FLIR today though, so this weekend I will be taking data! By the way, I figure that all the valves on the manifold are set by default to be wide open so I need only to screw them in to REDUCE flow, right?? If so, I will plan on leaving the loops where I want to maximize flow wide open / leave alone, while throttling the low priority or already fast response loops, right?

I'm dying to see the IR image of your great room floor!

1. Basically set your pump head high enough to achieve flow in your toughest circuit.
2. Throttle any circuits that are over flowing while leaving the tough circuit wide open.
3. recheck your tough circuit, If you find your tough circuits to be overflowing reduce the pump head
4. recheck all the circuits again, you may have to open some up a little if you've changed your pump setting.

I don't totally trust those little flow meters, so keep an eye on your temp deltas. Looks like if you're supplying 105F your delta should be around 20F (in design conditions), but your delta may be higher at the design flow if your inlet temperature is higher too, or your delta may be a little lower if you choose to up your flow rates beyond design a little (gain a bit of capacity, and lose a small amount of boiler efficiency, and a bit more pump power).

Gordy

Agreed If they are set wide open. I agree with @SuperJ use temperature verses flow rates.

I’d be willing to bet your high delta loops have wide centers coupled with longer lengths.

schreib

By the way, still have not received the flow "key" adjuster.

OK guys, I here ya'. I assume all valves are default set FULL open below:

HOWEVER!
This all seems like an effort in futility with my Wilo automatic head control system pump. Please correct me if wrong, but as I understand its control algorithm it adjusts RPM on pump automatically to KEEP the delta P across the pump the SAME. So, now I have the pump set point maxed out at the 16 ft of head level. It will just always keep the RPM at whatever speed is needed to keep THAT head pressure. If I crank down a zone valve it will slow the RPM to keep 16 ft pressure at the pump. Throttling that valve will REDUCE flow to THAT ZONE. BUT, this will NOT result in an increase to other areas because the pump sensors will see the pressure increase and slow the RPM(/ ft of head) back to 16 ft, preventing any benefit in flow diversion to another zone!

The flow WILL decrease to zones throttled but stay same at my "problem" zone where the valve is already FULL open because it's feed remains at 16 ft.

schreib

SuperJ said:

I work in the building controls industry and agree the built in boiler controls function often end up producing some bad cycling behavior.

SuperJ: not sure how your most recent post got placed into a fresh thread but I responded there and that never showed up in this MAIN THREAD, so I am pasting my response again, here, so the other guys can view and the thread stays together:

Yes, I understand your points about FLIR imaging. I can see the tubes in thin flooring only after running the SH1 set point to 130°F and disabling the reset curve so boiler is maximizing output to tubes and not restrained by the reset. Without doing this there is no chance I would see ANYTHING! In addition, I had to cool the zone overnight so it was plenty low for testing next morning with 130°F system feed. I can see excellent images when viewing humans, fresh footprints on floor after removing foot, the heated boiler manifolds etc.

Actually, the unit is very capable and I did place COLD objects on floor like you describe and adjust the "mode" (six available) to accentuate dT. At one point I cooled a tape measure in ice water bath and hooked two ball point pens on it 11" apart and took FLIR of them on top of floor in kitchen. Kitchen floor is only 5/32" thick PVC. It was still hard to see the tubes in image. I believe the problem is not due to IR imaging capability but the fact that as the heat is transmitted from the bottom of the floor(tubes attached to top of foam with clips, 4" below concrete top) it disperses out from tubes in 3 dimensions and equalizes almost totally. By the time it reaches the flooring material there is already little difference from one place on surface to another and then it has to span and transfer to the flooring while equalizing a bit more. By the time the heat reaches the flooring surface there is little difference across any surface. This effect is maximized with having to go through carpet pad AND the carpet itself. The carpet has huge surface area(fibers) exposed to the air and this exponentially equalizes the temperature.

By the way, most all tubes throughout the home appear to be around 10 to 11" apart with not much different from center of rooms outward. However, I have not done an exhaustive view of all rooms. FLIR is too painful / near impossible to do with carpet and about 1/2 home is carpeted.

I will put out some IR images so you guys can see later and look in my construction photos before concrete pour for additional verification of spacing. Again, per earlier post, this may be all academic since adjusting flow may be(?) an effort in futility.

Gordy

First question is how do you know all valves are full open?

Gordy

Second question how do you know it’s the right circulator.

Gordy

Third question is why you didn’t select radiant friendly carpet, and pad?

SuperJ

DP at the pump is different than DP at the manifold. I forget how far your pump is from the manifold. As you reduce flow in zones that are overflowing your manifold pressures will get closer to the pump pressure. Giving you a little more pressure for the great room.

Sounds like the carpet might be a major factor. Was the hydronic design done with carpet in mind?

schreib

Regarding: Stratos ECO 16F/FX/BFX Stratos ECO 16F/FX manual attached here.
Gordy's questions:
-- I made what I "assumed" was a reasonable assumption that the manufacturer would by default set all valves in fully open position upon packing and shipping. NOT a good one?? I will call AquaHeat. Also, with THIS contractor I am basically 100% sure he did not adjust anything. . .
-- Come on now, I KNOW it is the right one.
-- I was not aware there was any such thing as radiant friendly carpet but I made a point of telling the sales guy that the flooring was going over a radiant floor. Please expand on radiant friendly carpet.
SuperJ's questions input:
-- two sets of manifolds: Near boiler, all but three loops are handled by manifolds directly below the system / distribution pump; virtually zero dP from pump to most manifold outlets; the other three loops are fed by a 1" PEX into a separate manifold about 30 ft from boiler. Two ZONES only use two loops, other ZONES use only one loop each.
-- The heating system was installed with full knowledge that carpet is on some areas. Please expand on what changes I should have made to the carpeting to best accommodate radiant in the floor slab. I DID install 3" of foam underneath, not 2" which is common. I had no input beforehand that indicated I should NOT use radiant slab heat under carpet.

OK, I guess you are saying with the situation you still believe that reduction in flow in one area will, in fact, divert flow to another even if the auto control on the WILO pump is working as designed back at the pump location.

Hey guys, I WILL try to balance the flows(if I ever get the dang key!). I just felt it was a good idea for you guys who have direct experience(with the WILO auto head pump) how it is expected to work in this case. Trying to guess, I came up with my own expected result: nothing will happen. Obviously, I must be wrong then?? What has been YOUR experience with these WILO pumps? thanks.

OK, so back to my question. Do you all feel it has no basis in reality? Am I missing something on HOW this pump is supposed to work or will work here? All I am saying is the pressure at the pump outlet, will stay at say, 5 psi, and I have no reason to believe the input pressure will change (significantly) if the flow is reduced. So, if I have a bunch of pipes going out but shut down the feed entirely to ONE zone, it will require pump RPM's to drop to keep the pressure on it's outlet constant and will reduce the flow accordingly. If it did NOT reduce RPM the same flow going to less zones would increase the pressure and flow in the other zones and result in a different dP across the pump. My point is simply that the control scheme for this pump design causes it to reduce RPM to keep the dP across the pump the same.

This pump, therefore, reduces the flow by that which formerly went into the leg that was shut down. However, the pressure drop from the pump to the Great room can not change-- same length of pipe and number of els involved. So, the pressure needed to keep its feed the same is still 5 psi. OR, tell me how my reasoning is messed up. . . thanks!

schreib

Just in this morning:
Spoke with both Aquaheat re: manifolds and Wilo and learned the following:
-- I am correct in the understanding the WILO pump control will counteract attempts to divert flow into a "needy" zone by throttling flow to others. Basically, its design is to negate the need to balance flows; only requiring throttling zones that put out too much heat.
-- I should use the manifold flow valves to REDUCE flow that is too high, per Aquaheat. The manifolds are shipped with valves FULL open and they are ready to be adjusted down, reduce flow.
-- Wilo pump expert suggested best way to increase my system output in the Great Rm is to install a separate pump for those two loops and let the Wilo Stratos pump run the rest. He confirmed my assumptions that flow adjustments will not have an effect to increase flow further.
-- I will still remove all the actuators and verify that all valves are full open as suspected.
-- Aquaheat's install manual includes many things including stuff about radiant "friendly" carpet: glue down the carpet pad, use carpet with jute backing. However, it also shows that the difference in heat output of the surface is reduced from 28,000 to about 26,500 for linoleum, to about 22,000 Btu/hr/sqft for carpet. Its graphs showed NO difference between plush carpet and normal carpet for reduction in output. My carpet is not glued and no jute backing, pad has 0.7 R value, no R value listed for carpet, only thick pad is in Dining rm, kept cold anyway.

SuperJ

You're correct about the constant pressure having a defeating effect on balancing, but it's a little more complicated since you are trying to run near max head (for your pump). 15-16fthd pressure is only available at 5-6gpm flow rate. If your flow goes higher the pressure will go down (see pump curve below). This means as other zones call for heat your pressure may drop.
Adding pumps is a fairly drastic measure, you should go thru the balancing exercise first.
Another question is, have you used the FLIR camera to look at your building envelope in the great room? It could be your floor is performing as designed, but the heat loss is higher than expected, or your house is under negative pressure and leaking in cold air.

SuperJ

You mentioned reading 5psi on the outlet gauge that seems way too low...
Assuming you have a proper expansion tank setup, how much does the output pressure change when you turn your pump on and off?

16 feet of head is about 7 psi, but you should at least 10psi in the system (not differential pressure, just static system pressure). So when the pump is off your output gauge should read at least 10psi, when the pump is maxed it should read 7psi higher (17psi in my example).
This is assuming your pressure tank is on the suction side of the pump and correctly setup.

Gordy

Also is night set back on the pump active?

schreib

Gordy, No, no setback. It is on right side of dial, a little SUN.

SuperJ: sorry, the 5 psi number was pulled from the sky, an example only to set up a hypothetical situation

schreib

NOTE that on your curve peak is really only 14.2 ft of head. Wilo tech pointed that out to me also. Unfortunately my cheap **** plumber did not put any pressure gauges on this system. Only plumbing gauge was a T & P at boiler output that is nearly unreadable because he pointed it straight up and piping is in the way and the print is TINY. Thanks for pointing out expected operating pressures etc.!

schreib

No have not used the FLIR to asses the great room windows etc.
However, I have top of the line Marvin windows and the house blows 1.0 on the blower door test. VERY tight house even with the big fireplace.
Still confused about the details that should motivate me to go much further on balancing besides verifying that all manifold valves are FULL open? It sounds like you are concerned with pressure dropping out in the system piping. . . I admit things are more complicated possibly. So, if you were to TRY to balance things what process would you use here? I figure I would have to one by one check all the valves first to verify their open position relative to 100% open and assume would find them all open. Then what? force one stat to feed one of the zones needing LESS flow to be ON -- after cranking its valve down a bit and re-installing all the actuators? Then look to see if the flow in the Great room is actually higher??? I just need some basic process to take into account the logistics if you have something in mind. thanks!

schreib

"You're correct about the constant pressure having a defeating effect on balancing" just want to point out SuperJ, not constant pressure but constant pressure drop across the pump.

So, per your thinking above. . . let's say we are running at 17 psi and then a zone drops out after being satisfied. . . the pressure is being controlled across the pump at 16 ft(present setting), so with the need for less flow the RPM will be reduced to keep that dP at 16 ft. Not sure if that is useful to the discussion. . . but if I WANTED to compare the situation with a valve in this other zone being cranked down, not the zone dropping out, I would have to remove the actuator, crank down the valve, re-install and then start the system up and watch for change in flow for both the 2nd zone and the Great room. Those kind of logistics is what I need to determine I need to do before I start messing with stuff, it seems.

SuperJ

If you are getting an accurate flow and temp delta on the zone and the btu output is close to the design Then the design calc or the building is off since the proper amount of heat is being delivered. So we are kind of grasping at straws here to try and boost output. You’ve already increased temperature so the only other way to get more output, is more flow and redirecting capacity from other areas (balancing).

But to be clear. You will not get anywhere near full pump performance if you don’t have adequate pressure on Suction side of the pump. Can you confirm the pressure reading on the t and p gauge at the manifold with your pump off? You don’t want negative suction pressure as you will get cavitation and low performance. Just because your pump is set to 16ft of head doesn’t guarantee it can produce it.

I want to rule out low system pressure as a potential problem.

SuperJ

While you’re waiting for the key... If you have ball valves on your zones you could do a rough balance as a test by throttling zones that have no problem.

schreib

P & T is at 15 psi(30 ft) and about 118°F, all pumps off.

schreib

Found Out from Aqua heat I don't need the goofy key, just a 1/4" hex socket will work.
But no ball valves. So, just pick a couple of zones that appear to be easily / quickly satisfied and throttle them back and look for increase in flow in great room? right? -- after removing all actuators to verify all are OPEN!