Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

I wonder if ChrisJ is stable yet ?

2

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    No, It's really not as amazing as one might think. I am going to talk about something and I know everyone will doubt this. That's fine.

    If no one believe this I don't care.

    In another life I spent about the first 16 years of my career working for a contractor where we were a commercial oil, gas and gas/oil burner installer #2-#6 oil

    At that time in my location we were the factory reps as well for two different manufacturers. I won't mention the mfg. names but they were (and one still is) one of the most popular burner lines available. There burners are used by Peerless, Weil, Smith, Burnham,Columbia, Hurst....You name it.

    They sold a ton of equipment and still do.. Back then they had no factory start-up or service. If you were a dealer you were on there own.

    I sold and worked on this stuff all the time. If anyone in the northeast had a problem and they couldn't resolve it with the factory I would get called in by the factory or the factory would have the contractor call me.

    The name plate on the burner meant nothing. We had stuff that was supposed to be able fire 40gph #4 oil, couldn't get 30 through it without smoke.So it was downfired and the readings were good. Usually nobody cared, as long as you could heat the building nobody was the wiser, just had an underfired boiler.

    But on a few jobs we had to prove capacity, couldn't do it without major modifications. Not an isolated problem they built stuff that couldn't come close to there catalog ratings all the time

    that was 30 years ago

    But some things never change. A couple of years ago (maybe5) they started selling burners to Buderus. I work for a different company and don't do burners much now.

    My company got called in to start up 6 #2oil/gas burners factory packages sold to Buderus to use on their CI boilers in the Boston area. the tech that went their called me as I worked in the office at that time. gas was ok, firing on oil was........miserable and impossible.

    I went to 1 job and worked with him and started another job up myself.....disgusting on oil.

    I called the factory and demanded to know who did the testing of the"xxx"burner on the Buderus boilers. Did XXX company or Buderus do it??

    Well "we did "some" testing out here xxx told me"

    Nonsense they did nothing.

    We ended up taking the removable baffles out of the boilers to drop the furnace pressure to make it work. Numbers didn't match anything it was supposed to.

    Bottom line, some manufacturers are great. They test the crap out of there equipment and it will work as stated (unless you have a unusual job condition)

    Other manufacturers suck, they test very little if at all. "let the guy in the field figure it out"

    if your putting burners on a particular model boiler and buy the "factory package boiler & burner", and lets say that boiler model like a Smith 28 or a Weil 88 can have as few as 4 sections or as many as 20. do they test them all??

    Do you really think they test fire oil on a 4 section, then gas, then combination gas/oil? then a 5,6,7............20section on those different fuels??

    We all know the answer to that. And I visited their factory twice years ago.

    Now, I know AC is different, but I take what ANY manufacturer tells me with a grain of salt.

    Set it up their way first, If it doesn't work start changing stuff.

    The manufacturer that doesn't lie isn't in business yet

  • ChrisJ
    ChrisJ Member Posts: 12,647
    edited July 2017
    Does anyone know how the AHRI testing works on units like this?

    Who does the testing? Does the product have to be identical to what's being sold to the public?

    I also couldn't find whether or not 2 stage units are tested in low stage or not. Best I could tell, they are not.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • KC_Jones
    KC_Jones Member Posts: 5,076
    ChrisJ said:

    Does anyone know how the AHRI testing works on units like this?

    A simplified version of what happens is this. The company will test and calculate performance for the entire product line. They will then test some number of units (could be 1 depending on how big a line is). After that AHRI will come in and repeat the tests to their satisfaction. The ratings that come from the test are then applied to the theoretical calculated numbers and extrapolated for the entire product.

    There will certainly be variation on performance from actual to the "tested" capacities. They can't test everything, unless you want your AC unit to cost 10k to pay for all that testing.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    ChrisJ
  • ChrisJ
    ChrisJ Member Posts: 12,647
    > @KC_Jones said:
    > Does anyone know how the AHRI testing works on units like this?
    >
    >
    > A simplified version of what happens is this. The company will test and calculate performance for the entire product line. They will then test some number of units (could be 1 depending on how big a line is). After that AHRI will come in and repeat the tests to their satisfaction. The ratings that come from the test are then applied to the theoretical calculated numbers and extrapolated for the entire product.
    >
    > There will certainly be variation on performance from actual to the "tested" capacities. They can't test everything, unless you want your AC unit to cost 10k to pay for all that testing.

    Any idea if low stage is tested on 2 stage units?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    And THAT is why we get crap in the field to fix. When they send it out the door it has only worked on paper or in somebody's dream.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    Really want to see how this works after you change the txv. Factory F Ups really piss me off
  • ratio
    ratio Member Posts: 3,122
    But, it can be proven to work. Just let me show you. Hand me my calculator. ;)
  • ChrisJ
    ChrisJ Member Posts: 12,647

    Really want to see how this works after you change the txv. Factory F Ups really piss me off

    I'll be sure to post updates whether it works, or not.
    The new 3 ton valve and a new solid core drier will be here Wednesday, though there's a good chance I won't be changing the drier as long as all goes as planned.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • KC_Jones
    KC_Jones Member Posts: 5,076

    And THAT is why we get crap in the field to fix. When they send it out the door it has only worked on paper or in somebody's dream.

    Short of testing the 10's of thousands of combinations out there I'm not sure of another way. Either that or there is 1 system to choose from for every application, but it has been tested and verified to work perfect in all situations.

    My company currently has 76,000 AHRI certificates for evaporators alone. No one can possibly test all those. So the companies either shrink the product line to an extremely limited selection or some math needs to be done. It's not perfect, but what would be better?

    Sometimes people make mistakes, sometimes a manufacturer makes a mistake. With the volume that some of these companies run I would venture a guess the error rate is relatively low. I know roughly what our is and even though people beat on us on occasion we do pretty well.

    What should upset people is the companies that don't get certified and blatantly lie about what their equipment can do. Yes they sell equipment that they absolutely know will not perform, but they are banking on people not realizing it due to installation or over sizing or just not paying attention. Many if not all the competitors in the market I am in do this.

    The issue I have with @ChrisJ situation isn't the problem itself, it's the lack of support from the manufacturer. The company I work for (industrial HVAC/refrigeration equipment) at a minimum would have sent a new valve. If that wasn't to the customers satisfaction we would have sent someone to the job site and fixed it on our dime. I know residential would never go to that level, but they should be doing something.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • Gordy
    Gordy Member Posts: 9,514
    edited July 2017
    My intuition says their ratings are not based on low stage. Although it may be tested.
  • Fred
    Fred Member Posts: 8,518
    I think Goodman was acquired by Daiken a couple years ago. Are you dealing with an older Goodman product or one produced since the Daiken acquisition? Goodman was never known for the quality of their products or their customer service. Daiken, on the other hand has a better reputation and I'm wondering if contacting them might yield better support. .I believe I read that Daiken bought Goodman so as to enter what they considered the "entry level" market. It may also well be that there is a push to piece together systems using up old Goodman inventory, and may, in some cases, compromise the original design but makes the switch to Daiken designs less costly (or so they think).
  • ChrisJ
    ChrisJ Member Posts: 12,647
    Well,

    There's is interesting.
    I ordered the TXV my outdoor unit says to use, Goodman Part# TX3N4.

    Here's what the box says. According to Emerson, they class it as a 4 ton valve, yet on the box it says 3 ton?





    Should I even bother trying this one?

    Also, I expected to get a Parker valve, are all TXVs in a certain size range the same dimensions? As in, should the inlet and outlet on this one, line up with the same size valve from Parker? The connection types are correct, though Parker called them "Flowrater" I believe.

    I'm thinking flowrater is a Goodman name and Chatleff is the actual name for the connection, but that's a guess on my part.

    I'm a bit surprised as all of the pictures I've seen of this kit appeared to have a Parker valve. Also, it's listed as 2.5 to 3 tons.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 12,647
    Pretty sure I'm going to return this TXV.
    Not because it's a "4 ton valve" but because I'm concerned about the location of the equalizer tube and it clearing the cover on the air handler.

    I ordered an HCAE-3-KX200, which is a Parker identical to the 6 ton that's in it, but only 3 ton nominal.

    @EBEBRATT-Ed Those 10 ton systems you installed the 8 ton valves on, did those have distributors on the evaporators like these small ones do? The distributors seem to have quite a bit of pressure drop across them by nature. 40, even 50 PSI apparently?

    What actually happens in a system like that with an "undersized" valve? Does the system simply build pressure until it passes the right amount of refrigerant? Or does the evaporator starve? I'm picturing lower ambients, say, 55-65F.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 12,647



    I'm not sure how low the high side gets when it's chilly out, but this is my current concern.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    @ChrisJ , you are correct. The high side pressure rises slightly so the smaller txv will pass the flow. All a txv knows is superheat, that's all a txv controls directly is superheat.

    Everything else that happens is subsidiary to superheat.

    IMHO if you have a 3.5 ton system I would use a 3 ton valve. Especially where your probably be on low stage most of the time the smaller valve will control better at low load.

    also you are correct Chatleff is a different type of connector.

    Yes, all the larger evaporators all have distributors. most coils do now. Larger coils have to have distributors to effectively distribute the refrigerant.

    The 10 ton circuit we did with a Trane supplied Condensing unit and a Trane supplied evaporator coil is not "matched set" like residential because it was a hospital op room. Our coil connections were 1 3/8" suction and 1 3/8" liquid from the factory.

    we ran 5/8 liquid line and a 1 1/8" suction line. The 8 ton txv I think was 5/8" inlet and 7/8" outlet (cant remember)

    So now that got you going from Parker/Sporlan to Emerson which I think is Alco
    ChrisJ
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    I looked up the #NAE-4-zaa-cha. Says it's a 4 ton valve. Yet the box says 3 ton.

    Confusing.

    I think the 0151R00102 is maybe a Goodman #
  • ChrisJ
    ChrisJ Member Posts: 12,647

    I looked up the #NAE-4-zaa-cha. Says it's a 4 ton valve. Yet the box says 3 ton.

    Confusing.

    I think the 0151R00102 is maybe a Goodman #

    I have a 3 ton 2 stage system, just the evap is used "up to" 3.5 tons.

    So you feel the "3" ton valve should work fine, even if it's say, 55-60 outside? There's times the system runs under those conditions.

    Obviously, the system should be in low stage (2 tons) under such conditions, and not even entering high stage until it's in the mid 80s outside, however it can happen. Dropping the t-stat 2-3 degrees will throw it in high stage every time.


    Tom's system is using a "4" ton Emerson valve on a much larger evap, but similar 2 stage 3 ton outdoor unit. Works beautiful.

    Something else odd is Goodman says to charge in low stage, and they want 5-7 SC and 7-9 SH. Why?
    7-9 SH seems terribly low, but I'm assuming it's related to it being in low stage.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    txvs have a fairly wide capacity range. Just don't want a valve that is constantly forced out of it's range. Running 1 stage the valve will "pinch down" and with cooler outdoor air temps the discharge and liquid line temp and pressure will be lower which will reduce the valves capacity which is what you want.

    Don't know why they would charge in low stage.
    ChrisJ
  • ChrisJ
    ChrisJ Member Posts: 12,647

    txvs have a fairly wide capacity range. Just don't want a valve that is constantly forced out of it's range. Running 1 stage the valve will "pinch down" and with cooler outdoor air temps the discharge and liquid line temp and pressure will be lower which will reduce the valves capacity which is what you want.

    Don't know why they would charge in low stage.

    That part I get.
    But what exactly happens in high stage with cooler outdoor temps?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    High stage with cooler temperatures the head pressure would be lower which will slightly reduce a txv capacity. With normal comfort cooling you would expect less load indoors with cooler outdoor temps. I would expect lower discharge pressure and lower suction pressure . The superheat should stay the same because that's all a txv controls

    If this was something other than "comfort cooling" like a lab, or process cooling where the (evaporator) load remains the same with cooler outdoor temperatures then the suction side would stay the same. The discharge pressure may drop slightly due to cooler outdoor temps, but not much because the indoor load keeping the suction pressure up will also keep the discharge pressure from falling.

    how much gas the compressor pumps depends on the differential pressure it is working against

    lowering suction and or raising discharge reduces gas pumped
    raising suction or lowering discharge increases gas pumped.

    the compressor and evaporator are constantly "balancing" each other .. like a see-saw. air flow and air temperature..load should not force the compressor to have to work outside it's "design envelope".

    the condenser has to reject the heat absorbed by the evaporator + the heat of compression. TXv just controls superheat.

    dirty coils, plugged filters, bad txv, high or low etc fore a compressor out of it's design envelope=compressor failure
    ChrisJratio
  • ChrisJ
    ChrisJ Member Posts: 12,647
    > @EBEBRATT-Ed said:
    > High stage with cooler temperatures the head pressure would be lower which will slightly reduce a txv capacity. With normal comfort cooling you would expect less load indoors with cooler outdoor temps. I would expect lower discharge pressure and lower suction pressure . The superheat should stay the same because that's all a txv controls
    >
    > If this was something other than "comfort cooling" like a lab, or process cooling where the (evaporator) load remains the same with cooler outdoor temperatures then the suction side would stay the same. The discharge pressure may drop slightly due to cooler outdoor temps, but not much because the indoor load keeping the suction pressure up will also keep the discharge pressure from falling.
    >
    > how much gas the compressor pumps depends on the differential pressure it is working against
    >
    > lowering suction and or raising discharge reduces gas pumped
    > raising suction or lowering discharge increases gas pumped.
    >
    > the compressor and evaporator are constantly "balancing" each other .. like a see-saw. air flow and air temperature..load should not force the compressor to have to work outside it's "design envelope".
    >
    > the condenser has to reject the heat absorbed by the evaporator + the heat of compression. TXv just controls superheat.
    >
    > dirty coils, plugged filters, bad txv, high or low etc fore a compressor out of it's design envelope=compressor failure

    Curious how do you lower evap temps when using a txv? For say a walk in freezer? Just run higher SH?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    Just lower the set point of the box thermostat.

    Compressor runs, box temp drops. As box air temp drops suction pressure follows the box temp...down in this case.

    Superheat stays the same. Pressure differential across the compressor goes up (suction drops, discharge stays about the same). Higher differential compressor, becomes less efficient...pumps less gas. Compressor amps???should go up with higher differential but lower suction pressure means suction gas is less dense so less gas by weight is pumped which would lower amps.

    I have seen old walk in boxes that had no box temp control.

    They use the low pressure switch on the suction line. You set the suction pressure (converted to temperature on a T & P chart about 10 degrees below the box temp you want. Walk in box coil temp is usually about 10 deg colder than the box to PREVENT dehumidification ...drys out the food or flowers.

    Opposite of air conditioning where we run say a 40 deg coil with 74 return air..big TD dehumidifies better smaller TD less moisture removal
    ChrisJratio
  • ChrisJ
    ChrisJ Member Posts: 12,647
    > @EBEBRATT-Ed said:
    > Just lower the set point of the box thermostat.
    >
    > Compressor runs, box temp drops. As box air temp drops suction pressure follows the box temp...down in this case.
    >
    > Superheat stays the same. Pressure differential across the compressor goes up (suction drops, discharge stays about the same). Higher differential compressor, becomes less efficient...pumps less gas. Compressor amps???should go up with higher differential but lower suction pressure means suction gas is less dense so less gas by weight is pumped which would lower amps.
    >
    > I have seen old walk in boxes that had no box temp control.
    >
    > They use the low pressure switch on the suction line. You set the suction pressure (converted to temperature on a T & P chart about 10 degrees below the box temp you want. Walk in box coil temp is usually about 10 deg colder than the box to PREVENT dehumidification ...drys out the food or flowers.
    >
    > Opposite of air conditioning where we run say a 40 deg coil with 74 return air..big TD dehumidifies better smaller TD less moisture removal


    I see similar on the monitor tops. As the evap pressure drops so does the power consumption but I assumed that was from the compressor running out of stuff to pump around 28"
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 12,647
    Have a selection of TXVs now.

    The box on the left is from the replacement "proper" TXV. The other two I bought and they're almost identical. Parker says the "Z" charge may result in slightly higher SH than the "K" charge but should work fine.

    I'll likely be installing the top one though.


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 12,647
    Current goings on.
    Valve is swapped, pulling a vacuum.

    I flowed N2 the entire time so I left the filter drier alone.






    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    get that baby on line want to see the results!!!!!
    ChrisJ
  • ChrisJ
    ChrisJ Member Posts: 12,647
    Confidence is high.....


    Tuning the SH right now. Looks like I'm going to be about 1 1/2 turns more open than "stock".
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 12,647
    edited July 2017

    get that baby on line want to see the results!!!!!

    Ok so,

    Goodman says to charge in LOW and aim for 5-7 SC, 7-9 SH.
    I did my best, my SC is still moving up and down slowly, as is the highside pressure. This could be from the sun as it keeps coming in and out of the clouds and it's HOT.

    However, my lowside is rock steady, currently at 151 PSI. SH is on the higher side, 7-9 degrees depending on a few things, again, I suspect the sun may be having an effect on it. I also still have the cover partially off of the unit in the attic as I had to adjust the TXV a few times.

    In high stage...
    Fairly steady pressures, 12F sc, 12F sh.

    I don't know, I think it's done.

    @EBEBRATT-Ed What do you think?

    I need to get the cover back on the AHU, which will drop my low side pressure for sure, but I'd expect everything to stay proper, i.e. sh and sc.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 12,647
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    Sounds a lot more stable that's for sure. You should get a job at Goodman sizing TXVs!!!!!!
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,221
    That looks golden, considering that the evap is in the attic. The slightly higher SC accounts for the lift and line loss.
    I would never be happy with a 5 to 7 degree superheat unless I had an accumulator installed. Or unless it was a flooded evap type refridgeration system. At that range superheat, "measuring the outside of the pipe" you are getting droplets of liquid return. At 12 at the compressor, you are good. Have you measured the superheat at both the evap and the condensor?

    My opinion is that you have the system performing about as good as it safely can.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    back in the day it was 15-20 sub cool or stop when the sight glass was full whichever came first & 15-20 superheat for Copeland while Carlyle compressors (Carrier) was around 12 deg superheat.

    I suppose the lower#s are to gain efficiency. But as has been proven in the past compressors don't make good liquid pumps.

    When scrolls first came out a lot of MFG. skipped putting crankcase heaters on because "scrolls can pump liquid" or so we were told which was a fantasy. A short time later most of them were back to the CC heaters. The BLUE OVAL of course because they know everything was the biggest offender.

    Isn't it amazing what the right size valve will do?

    For what insane reason would they use a 6 ton valve?? And then insist it's the correct size
  • ratio
    ratio Member Posts: 3,122

    For what insane reason would they use a 6 ton valve?? And then insist it's the correct size

    It depends. I do believe that there are really good engineers out there, the kind who understand every aspect of what they're working on, & can "miss use" things, so that these-operating-conditions and those-side-effects can add up to what-we-want-to-happen. So I'm quite willing to concede that the possibility of the 6 ton valve being correct exists. But I also think there are a lot more "engineers" out there without the intense understanding necessary to be Good—adequate is the best they can hope for if they don't understand completely.

    The question is, which kind specced the valve.

  • ChrisJ
    ChrisJ Member Posts: 12,647
    @EBEBRATT-Ed @ratio @Harvey Ramer

    Being this is the only system I've ever seen a TXV in operation, I have no way of knowing what's "normal" aside from what the manufacturer's of the valves say.

    My understanding is such.

    A TXV\TEV doesn't care what the highside does. It also doesn't care what temperature the evaporator operates at. All it does, is makes sure the suction line is X amount of degrees above the evaporator's temperature, whatever it may be.

    It, when operating properly will also maintain super heat fairly steady, regardless of changing conditions.

    Is this correct?

    @Harvey Ramer I'm a bit confused by your comment regarding super heat. How can droplets of liquid exist even at 1 degree of super heat? Or do you mean, running low super heat means there at times, when we aren't looking that we could be getting droplets back (zero SH) ?


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,896
    @ratio, everything I have ever read, everyone I have ever talked to about TXVs have always said "don't oversize it, if your between sizes go with the smaller valve"

    If you have a compressor that moves 3 tons worth of refrigerant then only a 3 ton valve makes sense.

    The only time this deviates is that txvs are sized for "nominal air condition tonnage" So a 50 ton compressor unit with a 50 hp motor used to freeze an ice skating ring only can move 38 tons worth of refrigerant because evap pressure is so low (high compression ratio) (it's a freezer) so a 38 ton txv is the right choice.

    get the charts out and size your own TXVs. you will find in some cases the mfgs are wrong.

    The only thing you need to know when sizing a txv is the expected liquid line pressure -the expected suction line pressure (pressure differential) and the txv controls to superheat. That's all the valve knows
  • ChrisJ
    ChrisJ Member Posts: 12,647
    > @EBEBRATT-Ed said:
    > @ratio, everything I have ever read, everyone I have ever talked to about TXVs have always said "don't oversize it, if your between sizes go with the smaller valve"
    >
    > If you have a compressor that moves 3 tons worth of refrigerant then only a 3 ton valve makes sense.
    >
    > The only time this deviates is that txvs are sized for "nominal air condition tonnage" So a 50 ton compressor unit with a 50 hp motor used to freeze an ice skating ring only can move 38 tons worth of refrigerant because evap pressure is so low (high compression ratio) (it's a freezer) so a 38 ton txv is the right choice.
    >
    > get the charts out and size your own TXVs. you will find in some cases the mfgs are wrong.
    >
    > The only thing you need to know when sizing a txv is the expected liquid line pressure -the expected suction line pressure (pressure differential) and the txv controls to superheat. That's all the valve knows

    what about distributor PSI drop ? How do you calculate that?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,221
    > @ChrisJ said:
    > @EBEBRATT-Ed @ratio @Harvey Ramer
    >
    > Being this is the only system I've ever seen a TXV in operation, I have no way of knowing what's "normal" aside from what the manufacturer's of the valves say.
    >
    > My understanding is such.
    >
    > A TXV\TEV doesn't care what the highside does. It also doesn't care what temperature the evaporator operates at. All it does, is makes sure the suction line is X amount of degrees above the evaporator's temperature, whatever it may be.
    >
    > It, when operating properly will also maintain super heat fairly steady, regardless of changing conditions.
    >
    > Is this correct?
    >
    > @Harvey Ramer I'm a bit confused by your comment regarding super heat. How can droplets of liquid exist even at 1 degree of super heat? Or do you mean, running low super heat means there at times, when we aren't looking that we could be getting droplets back (zero SH) ?

    @ChrisJ
    Technically they can't. But how are you going to get a superheat reading that accurate. You are measuring the temp on the outside surface of the pipe. Depending on your equipment and measuring location and procedure, your measurements can indicate a higher Freon temp than exists inside the pipe.

    And you are correct on the function of the TXV. It maintains superheat, that's it. In order to change evap temp, you have to change air flow/load.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,221
    An externally equalized TXV will compensate for any pressure drop through the distributer and evap.
  • ChrisJ
    ChrisJ Member Posts: 12,647
    edited July 2017
    <blockquote class="Quote" rel="Harvey Ramer">> <a href="/profile/ChrisJ">@ChrisJ<;/a> said:

    > <a href="/profile/EBEBRATT-Ed">@EBEBRATT-Ed<;/a> <a href="/profile/ratio">@ratio<;/a> <a href="/profile/Harvey">@Harvey<;/a> Ramer

    >

    > Being this is the only system I've ever seen a TXV in operation, I have no way of knowing what's "normal" aside from what the manufacturer's of the valves say.

    >

    > My understanding is such.

    >

    > A TXV\TEV doesn't care what the highside does. It also doesn't care what temperature the evaporator operates at. All it does, is makes sure the suction line is X amount of degrees above the evaporator's temperature, whatever it may be.

    >

    > It, when operating properly will also maintain super heat fairly steady, regardless of changing conditions.

    >

    > Is this correct?

    >

    > <a href="/profile/Harvey">@Harvey<;/a> Ramer I'm a bit confused by your comment regarding super heat. How can droplets of liquid exist even at 1 degree of super heat? Or do you mean, running low super heat means there at times, when we aren't looking that we could be getting droplets back (zero SH) ?



    <a href="/profile/ChrisJ">@ChrisJ<;/a>

    Technically they can't. But how are you going to get a superheat reading that accurate. You are measuring the temp on the outside surface of the pipe. Depending on your equipment and measuring location and procedure, your measurements can indicate a higher Freon temp than exists inside the pipe.



    And you are correct on the function of the TXV. It maintains superheat, that's it. In order to change evap temp, you have to change air flow/load.</blockquote>


    That was my concern with the hunting valve. How could I be sure my sensor was updating that quick. It seemed impossible.

    Here's Goodman's charging instructions.
    My guess is their SC and SH numbers are low, because it's in low stage. In high stage they both go up. I was seeing 12-13 degrees SH in high stage.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 12,647
    edited July 2017


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment