Bypass Heater with Automation System

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repair_guy said:
I was involved in that other thread. That guys specs were way out of whack and I'm not sure what he ended up finding. It may have been a bad drive. The pump defaults to 75 degrees. Even if you neglect to correct it, the gpm would not be off by more than a few gallons. There is no flowmeter in the pump. The pump measures resistance as you know and with a preprogrammed system that says water molecules resist at this rate at this temp, it's just an equation at that point.
Click to expand...

So are you saying that they are not using a calorimetric flow meter? You mentioned that "the pump measures resistance" but what kind of resistance; mechanical, electrical, thermal, pressure? And how does it measure this resistance? And exactly how does it calculate flow from this measurement?

Technically speaking, no mater what method they are using, it is still a flow meter even if it is not a direct measurement. There are many different ways to measure flow rates some direct but most indirectly as the Intelliflo seems to do. From what you have said and others have said, the calorimetric flow meter makes the most sense. It measures thermal flow rates in the water in a very confined space and requires a reference water temperature to remain accurate.

[EDIT] I reread the gardenweb post, Intelliflo manual and parts lists and came to the following conclusions. The parts list doesn't show any separate sensors for measuring flow. Also, based on users comments, the Intelliflo does not show actual flow rates only set flow rate input by the user. This means that to come up with the proper RPM from a set GPM input value, the only other thing they can possibly use as an input to this equation is power draw (a form of electrical resistance). This can be done solely in the controller and the pump affinity equations would allow you to calculate RPM from a GPM value and power input values assuming that the efficiency is calibrated over the range of values. This would also make sense since they are showing power consumption in the display. I am still not clear why temperature is all that important then. Specific gravity of water only changes 0.7% from 50 to 100 degrees F so the calculations should have very little dependency on temperature and could have been ignored. I think Pentair recognized this in their manual when they said the setting is not all that important.
 
stever said:
I understand that the VF can also detect blockage and shut down. The VS does not have the flow sensor (calculator) and just pumps away, even if there is an obstruction. I don't know really how important this would be -- not likely there would be a blockage as there are required so many drain locaitons they would all have to be blocked.

Dows anybody here have the VF?
Click to expand...

Chemgeek has one and I think a few others do as well but I can't remember who else.
 
I have the full IntelliFlo (VF) and have it with the IntelliTouch i9s (was upgraded from i5s for free so I get macros since that wasn't clear during initial sale/installation). In theory, the full IntelliFlow was supposed to calculate how much water volume it has pumped and to turn off early if certain higher flow water features meant that the number of turnovers (one, in my case) had been reached earlier. With my solar system and its higher flow rate, I thought that would mean it would shut off earlier. However, after installation I found out that Pentair changed that algorithm so that it does NOT shut off when the turnover rate was reached. This means that the turnover and pool water volume settings simply calculate a flow rate for filtration mode which, of course, one could do manually.

So the only advantage to this pump seems to be in programming using flow rate instead of RPM. I can definitely tell you that it is measuring SOMETHING to get flow rate because I can hear the pump ramp up and see the RPM go up if there is more resistance such as from turning the eyeballs up (when I need to do more aeration). This implies that it will keep the flow rate roughly constant as the filter gets more resistance, but for me that's not relevant since I have an oversized cartridge filter that barely registers a 1 PSI rise all season and I only clean it once a year (remember that I have an opaque electric cover so my pool stays pretty clean most of the time, though some cedar needles always seem to find their way to the filter -- past both the skimmer and the filter basket though most get caught there).

I've never noticed the pump do the automatic shutdown on blockage except perhaps once when it was accidentally asked to startup with the valves turned off, but I don't remember for certain.

The RPM and GPM readings on the pump from my earlier measurements are certainly a mystery as Mark has pointed out. The GPM doesn't seem to follow the affinity equations very well for unknown reasons. I've never measured the flow rate independently so don't know if it's really accurate. I do know that there is a temperature sensor for the pump (it's a separate sensor put into the pipe and wired to the IntelliTouch) that reports the water temperature to my indoor control panel so might also be used for the pump's calculations of GPM.

All in all, I'm very happy with the new pump as I also use it to replace my older Letro Legend with separate booster pump. Now I have the IntelliFlo drive The Pool Cleaner pressure-side cleaner at 15 GPM and it works fine though I had to add a valve to solely drive the cleaner on its separate line during off hours (I didn't want the cleaner on while we were in the pool so I run it off-hours). My overall energy savings is around 40-50% and would be much higher except for having 12 solar panels that require 48 GPM for decent efficiency and those are on around 4-6 hours per day during much of the swim season. Overall, I'm very happy with the pump though technically the Intelliflo 4x160 (VS) would probably have been fine once I figured out the appropriate RPM -- I probably would have bought a separate flow meter in that situation.

Richard
 
A pool sweep will block quickly. I have my own and have installed many. The blockage protection is there for a purpose but on a bad installation, it causes more headache than anything. But, it serve it's intended purpose.
 
One other thing to mention, is that the 'auto control' Jandy valves can only 'understand' 2 positions --- ie they will be open or closed depending on how the valve is actuated -- in other words, there is no way to have an actuated valve only be partially open when using the automation (one can partially open one if they use the toggle switch on the unit)[/quote]

Jandy valve actuators can understand 3 positions because they do work on their 3-way valves
 
hypratt,

Confusingly, a three-way valve only has two positions.*

It is similar to the nomenclature for electrical switches. Say you have a light swith at the top and bottom of some stairs. Each of these switches only have two possible positions, yet they are called three-way switches.

Titanium

*This ignores the possibility of adjusting the internal cams such that the three-way valve ends up in an intermediate position that lets some water go in each of the two pipes. Even in this configuration, however, the three-way vlave STILL has only two positions - full travel one way and full travel the other way and nothing in between.
 
waste said:
One other thing to mention, is that the 'auto control' Jandy valves can only 'understand' 2 positions --- ie they will be open or closed depending on how the valve is actuated -- in other words, there is no way to have an actuated valve only be partially open when using the automation (one can partially open one if they use the toggle switch on the unit)
Click to expand...

Sorry to all for any confusion caused by this ~'incomplete' statement :oops: :cry: :evil: Titanium either knew what I was trying to express or just filled in from his own experience. I know that the stops can be changed/ adjusted as per the owners needs -- What I was attempting to express is, as Titanium pointed out, that the actuator only knows 'turn all the way clockwise or turn all the way counterclockwise' [some people who spend the extra $$ for the automation are disappointed by the fact that the valves won't let them have the spa spill over sometimes while still being able to isolate the spa from the pool] The only way to have the valve stop in a middle position is to manually toggle the switch on it and stop it where you want it (and if you forget to turn the switch back on, or switch it to the wrong(opposite) position, when you reactivate it - the pool doesn't run normally/ correctly) All I was trying to do was point out the limitation of the actuator being an 'all or none' thing (one of the guys I work with and I have been trying to figure out a way to make an actuator valve that would 'know' where it was in it's 360 turn and be able to stop in a 3rd or 4th... position -- results so far - bar makes a lot of money, we're still at 'square 1' {We're hoping that the next pitcher will yield some better results --- how do you brainstorm without beer?} -- if we come up with something possible, I'll bring it here for the experts to analyze :thumright:

Just wanted y'all to understand my original post { :sad: } :-D
 
I know what you mean -- there are only two positions. If I were to bypass the heater, I would set it to the 'bypass' mode of closing 'almost' all the way (to the preset stop most of te way closed) and then in the 'heat' mode the valve would be all the way open (toward the heater). Still two positions.


Hmmm... It would be a nice invention for a valve to have intermediate stops... I guess one could wire three or four valves in parallel (with restrictive piping such than the total area added to the size (really flow) of the inlet pipe) and turn them on one at a time.... brute forve way to solve it. Once the flow-meters (such as on the Intelliflo VF) are more available, I suppose they could be put inline to measure the results of the valve and send feedback to the electronics.... I just know of no electronics that would have the capabilities to interpret this data now -- you'd have to hook it up to your computer and automate it that way with home-made macros.

Steve
 
The loss all depends on how your system is plumbed. I do not think it is a good idea for all
the filter water to flow through the heater. Builders do this to save a valve. If you have a separate spa
then with a couple of valves you can heat both the pool and spa, or each separately. Then, use the filter
pump for filtering only. If you have only one pump you can then bypass the heater unless it is needed.
If you leave the heater in the on position and turn the pump off the water flow valve will turn off the
heater. This way you can heat the spa or pool by just turning on the pump.

Heater heat exchangers are made from very corrosion resistant materials. So, longevity should not be
a problem with any of the brands.

Cliff s
 
I think I have your answer. Sorry, I am new to TFP (longtime PF poster here) and I didn't see this message until now.

When I had an Ikeric installed, the contractor put in a 3-way valve to bypass the pool heater. The difference in flow with the heater bypassed is huge. I can run the pump VERY low with the heater completely bypassed. First, I had them come back and have the pump triggered to go to high speed when the bypass is turned off. I had them come back later and adjust the internal cams so that there is some water going through the heater when it is bypassed though. Here's why:

1. My pool controller was maxed out and they couldn't figure a way to "tie" the bypass off on the valve to the "activate heater" for the heater control. Maybe someone else could figure this out, but we couldn't. Two buttons must be pressed for the heater to function. Theoretically, with my setup, someone could accidentally trigger the heater with no flow going through it. Although it would automatically shut off, there might be some damage in the meantime. It is a large heater and not worth the possibility. With the small amount of water flowing through the heater, there is enough flow to run the heater if you accidentally forget to turn off the bypass.

2. The water seemed too hot coming into the spa in spa mode with the pump running at a lower speed. That's why I had the bypass off option trigger the pump to high speed.

3. I wanted to be able to run the pump in low speed during freeze protection. I live in the San Jose area and we have had a couple of months requiring frequent freeze protection here in the past couple of years. High speed would cost a fortune at our current electricity rates if it were running virtually around the clock.

4. I felt it would be beneficial to run water through the heater to keep everything flushed out.

Before I had them come back, I manually ran the 3-way bypass valve through various stages of bypass with the pump running. I have a pressure gauge on my filter and a suction gauge on my pump. Although I couldn't give you the exact numbers now, the difference is dramatic with the heater bypassed or not and this is a newer heater. They do introduce a lot of head (the heaters) and you will save money being able to run the pump at a lower speed when you are not using the heater.

Whether or not you choose to automate it or do it manually is up to you and depends on how much you use your heater etc. I probably could have gone with a manual valve and been perfectly happy, although I wouldn't have had the trigger to run the pump at high speed.
 

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Salinda,

Thank you very much -- that is exactly what I was thinking. A agree that a small amount of water would want to be routed through the heater at all times even when 'bypassed' just to make sure it's flushed out and doesn't burn up.

I will be useing an Intellitouch automation system. What automation system do you have?

Thanks again,

Steve
 
Sorry Stever about not responding sooner. I am new to the forum and for some reason I am not always getting alerted when I get replies to my posts.

I have an Ikeric pump but I use a Jandy one-touch automation system. It is an older one. I would really like the jva on my heater bypass if it was somehow linked to the heater firing or heater "on" setting so that it new to open full then. I don't like the "2 button to properly operate the heater" that I have now.

The "bypass" setting of the valve is set just high enough so that the heater can still fire even if it is left bypassed by accident. If you want, I can go run the valve manually and give you some pressure differentials at low and high speed so you get how it is working, but I will tell you it is very significant. The flow difference is noticeable too. I have a Pool Cleaner suction side cleaner and I have to practically turn the skimmer off completely if I want the pool cleaned and the heater running at low speed.

The other problem I have with my whole system, which was the result of a pool efficiency tear I got on 2 years ago, is that the variable speed pump that I have now doesn't move as much water at high speed as my old 2 HP Whisperflow did. What this means is that I really can't run solar and the heater at the same time when I am getting ready for a party on a hot day, for example. We have had weird weather this past 2 years when it will be in the low 70's and windy for a few days and then right into the 90's for a day or two. So although I know I am saving a lot of money on electricity, I feel the pump is undersized and everything is more fidgety. I don't want to be the only one in the household who understands how to run the pool. I don't want it taking so long to clean the pool and I hate it that the skimmer doesn't work as well as before because the flow simply isn't there. I know I was wasting energy, but the system was really nice and worked well. I should have stuck with what I had and done some other things to improve efficiency, like running the boostered Polaris (what I used to have) only every couple of days and for less time and running the pump for less time and only at the hottest time of day. When pumps and such start failing, that is the time for a big change, not before.

That being said, I would still recommend a bypass valve with a variable speed installation because
 
Salinda,

Yeah, I'd love to get some hard data on the difference between the bypass and not bypassed! This will help me lower the raised eyebrows of the plumber who is convinced that the way he's been doing it for 20 years can't be improved on.

Also, your lasy message ended with I'd recomend it because.... and the message was cut off. I'd love to hear your thoughts.

Also, how exactly is the bypass plumbed on your system? manual valve to always bleed some through?

Thanks!
 
I'll try to get you some data in the next couple of days. The bypass is a three-way valve with a jva at the input to the heater. There is a "t" at the output of the heater. Pool Power designed a smooth u to loop the bypass water around that doesn't go into the heater. (I'm not sure I buy that the loop has minimal head loss...it's kind of a funky looking thing with the loop.)

Basically, at full open all the water goes through the heater. At full closed, all the water would bypass the heater. My system now has the jva cams set so that the valve never goes to fully closed, ensuring that some water always goes through the heater. Initially, it was set so the jva would completely close so that the water could completely bypass the heater. In this position, the pressure on my canister filter was something like 4 psi! With the valve partially closed, the pressure is 10 psi, but the pump speed (frequency) had to increase a little too so that the cleaner could draw enough vacuum. I think at this point if the heater valve is open all the way, the low speed as I set it on the pump would not be sufficient to run the skimmer and cleaner.

When I want to heat the pool, I have to press the heater button and the heater valve button on my Jandy controller. The heater valve button sends a signal to open the heater valve and also sends a signal to my pump controller to run it at a higher speed. I can also heat the pool without telling the heater valve to open all the way, but it is very slow to heat and I don't like firing the heater for longer than I have to.

If you have a variable speed pump the bypass valve allows you to set the low speed much lower when you aren't using your heater, saving a lot of money. I am assuming your energy costs are similar to mine, since most of California is dealing with super-high rates right now.

I would install the bypass as a manual valve for now--that way you can always abandon it if it doesn't work for you and it cost very little to install--just plumbing parts. I personally only use the heater for the pool a handful of times and for the spa maybe once a week in the summer. You could always add the jva later.

Honestly Stever, I think I like the way you propose to plumb the heater bypass. The manual "bleed" looks very simple looks as though it would work. I've been following your build. If you could in any way link the automated heater bypass to the heater signal, that would automate it further to tell the system "I want to heat my pool now. Fire the heater and send the flow through the heater."
 
In my configuration, there is no 3-way valve to bypass the heater -- all flow always goes through the gas heater. Only the solar has a 3-way valve and I have another 3-way valve for the dedicated line to The Pool Cleaner. I have a custom flow set so that when the heater is turned on, the flow is turned up to 40 GPM automatically which is beyond the 30 GPM minimum the heater needs (I have it set higher partly for some extra room for safety keeping the heater cooler and partly for better efficiency of heating -- 40 GPM is still fairly energy efficient at 615 Watts compared to 48 GPM and 1500 Watts when the solar is on). When the gas and solar are off, I'm at 26 GPM and 275 Watts.

I never tried bypassing the gas heater so don't know how much additional energy I would be saving. I'm just so happy to have an overall 50% energy savings from where I was before with a fixed speed main pump plus a booster pump for the cleaner.

Richard
 
salinda said:
Basically, at full open all the water goes through the heater. At full closed, all the water would bypass the heater. My system now has the jva cams set so that the valve never goes to fully closed, ensuring that some water always goes through the heater. Initially, it was set so the jva would completely close so that the water could completely bypass the heater. In this position, the pressure on my canister filter was something like 4 psi! With the valve partially closed, the pressure is 10 psi, but the pump speed (frequency) had to increase a little too so that the cleaner could draw enough vacuum. I think at this point if the heater valve is open all the way, the low speed as I set it on the pump would not be sufficient to run the skimmer and cleaner.

If you have a variable speed pump the bypass valve allows you to set the low speed much lower when you aren't using your heater, saving a lot of money. I am assuming your energy costs are similar to mine, since most of California is dealing with super-high rates right now.

Honestly Stever, I think I like the way you propose to plumb the heater bypass. The manual "bleed" looks very simple looks as though it would work. I've been following your build. If you could in any way link the automated heater bypass to the heater signal, that would automate it further to tell the system "I want to heat my pool now. Fire the heater and send the flow through the heater."
Click to expand...

I want it automated, so I'll be putting in an auto valve. I debate between the way you have it (1 auto-valve with cam set to never close all the way) and the way I show it on my schematic (see pool build thread). I have the auto-valve opening all the way or closing all the way. I am concerned that while these valves are made to pe partially open/closed with the cams that in these partially open configurations they have a lot of head loss due to the internal vanes being in the way of the water flow. With the two valves I figure the flow in the heat off mode would be the full open auto valve (understanding that this is worse than no valve at all) plus the small amount manually calibrated for the heater. Between the two, I am guessing that the flow will approach the flow of a straight section of pipe without all of these bends and valves. In the heat mode, it would work the same way, but the two flows of water would join before the heater.

The intellitouch 7 will handle macros, so I am anticipating that I will be able to program the "pool heat" button to switch the valve, up the pump speed and turn on the heater. The spa mode would flip the pool cleaner valve off (if it's on), switch the bypass valves to spa, switch the heater bypass valve, switch the spa jets valve on, and turn on the heater. I hope it can handle all of this! I'll let you know in a few months (??) when we're all done!

You are correct, power is not cheap and somehow I feel better putting the $$ into the front and and having a lower monthly bill. I am planing on putting the Pentair Intelliflow VS pump now unless somebody convinces me that the VF is worth the extra $$.

Stever
 
Stever,

I actually think the way you have it is much better. The valve bypass you are proposing is cheap and I think it offers much easier fine-tuning.

The other thing that I meant to say about either setup is that we have freeze protection run quite a bit around here. Last year, it was unusually cold and the freeze protection was on for 24 hours for a couple of weeks and often for a couple of months. With the pump running in low speed and some of the water still going through the heater, my system was protected. The previous winter was not as cold and we didn't have the new system. My power use last winter (2006) was LESS than in 2005, when the original 2 hp Whisperflo pump was only running 2-3 hours/day.

I could not run the pump at as low a speed during freeze protection if I didn't have the bypass installed. Chem Geek's system is much simpler and has a lot to say for it, especially when you have a controller with no macros available.
 
I actually upgraded to the i9s controller which has macros, but not for the reasons you guys are talking about. It was more to ensure that certain program combinations wouldn't occur, specifically that turning on either the main pool circulation or the gas heater option would not have the pool cleaner turned on. Otherwise, 48 GPM for solar or 40 GPM for gas heat could get switched through a single dedicated line to the Pool Cleaner and probably would shut down the pump and/or would cause the pressure relief valve to be open a lot. Correctly programmed automatic settings wouldn't cause this, but human error could (i.e. turning something on at high GPM and then having the cleaner come on automatically -- the way custom flow settings work, the HIGHEST custom flow number from all active custom flows is used as there is no priority setting so macros can be used to overcome this limitation). I run the pool cleaner after the sun goes down to ensure that the solar won't get triggered, but that still left the possibility of someone turning on the gas heater before the cleaner came on so the macros prevent that.

As for the gas heater, mine did not have an electronic temperature control so I just set the temperature manually on the heater and one of the safety shutdown wires is connected to the Intellitouch. So, the gas heater won't get turned on unless the Intellitouch tells it to so I'm always guaranteed to have the correct flow when that happens (because of the custom flow setting associated with the gas heater "program"). Also, the gas heater has a flow detector to prevent turning on until there is flow and in fact I used to have the heater hooked up that way before I got my new pump and controller and never had a problem (i.e. the heater wouldn't turn on until the flow was at least at its minimum). The rocker on/off switch for the gas heater is always left on so the control is completely from the safety shutdown wire from the Intellitouch and internal triggers (e.g. flow detection or too high a temp)

Richard
 
Steve,

I didn't actually choose it. I originally had an i5s which is what I paid for, but then had all sorts of questions about it and when I originally talked to Pentair they said it would do things that it turned out it wouldn't, so when it got installed the installer called Pentair and the next time their technical rep was here I talked to him. The extensive feedback I gave and the miscommunication early on led the tech. rep to give me a free upgrade to the i9s. I didn't even know there was an i7s and you are right that I didn't need the extra valves as the i5s worked fine except for not having the macro capability. I only have two valves -- one for solar and one for my pool cleaner (to get a dedicated 15 GPM flow rate).

The other thing that was described on the Pentair website but turned out not to be true was how the VF with Intellitouch was supposed to keep track of cumulatively how many turnovers one did given the various flow rates over time. Then, the pump in filtering mode was supposed to shut off when it reached that number of turnovers (usually 1, though it's programmable). This would allow one to save additional cost when, for example, running solar which would then not need as much or possibly any additional pump time after the solar was off (because the solar GPM is higher than the normal filtering mode GPM). However, this feature was removed and instead the filtering is done on time and no automatic shutoff based on cumulative water volume is done. The entries for pool volume and turnovers are now only used to calculate a flow rate (something one can do themselves, of course). They said they removed the feature because customers complained that they wanted the pump over a period of time, but I suggested they make this a preference item so that users can go either way depending on their needs.

As for the VF vs. VS, I would say that if you get yourself a flow meter, then the VS should be fine. It is really nice to know the flow since, for solar in particular, one can fine tune the energy cost vs. efficiency. It's also nice to know the flow rate to determine the on-time for one turnover, though one can also use the "when does the water start to get dull looking" visual test. If you have a filter that rises in pressure significantly between backwashings, then the VF would keep the flow rate the same while the VS would not, but in my case I have a cartridge filter that barely registers even 1 PSI rise over a season (it's oversized so I only have to clean it once a year; and I have an electric safety cover which keeps most junk out) so this didn't matter. I just went with the VF because in the total price of my upgrade, it wasn't a huge part of the total cost and I hadn't read about flow meters on this forum at that time. :cry: My Pentair pump and controller was installed at the end of June last year (2007).

Richard
 

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