This was a service call on a walk in cooler that was iced up. I de-iced the coil and couldn't find anything wrong but I had a few ideas as to what could have caused it.
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So this convenience store, I stopped walking. They also got another to walk in boxes, oil, okay, so I shut the thermostat off. While I went and worked on another walk-in and when I came back, all the ice had fallen off the evaporator, so that was nice and easy. So that way I didn't get up to get the hose out.
Now it's important to pay attention. This ice is only about what six eight inches tall and not coils, much taller than that, and if you see in the original video I heard the beginning of the video I showed you, the coils were iced up, but it was only the bottom half of the Coils, it's important to pay attention to how they're iced up okay, when people call me - and they say - hey the coil is iced up and then later I find out it was only half iced up and they had already left that's a problem. Typically, if it's only half the coil, it's going to be a refrigeration problem, not necessarily someone even a door, it's not always the case, but majority the time it's not solid from top to bottom, it's gon na be some sort of a refrigeration problem. Now, if you come in and that's iced up from the top of the bottom to the from the top to the bottom of the clone, that's super thick like this.
That's an indication of a box getting too cold, possibly a defrost clock being back bad and or a door being left open. But again, not always it's just you've got ta pay attention and you got to be observant. There's nothing worse than someone telling me. You know it was iced up and then later on after they've left, assuming it was a door being left open.
I find out it was only half the coil iced up. It's like you know. We didn't go through the everything and look at the big picture. So without being said at this point, I'm gon na inspect the coils to make sure that they're clear and that they're clean I got to get on the ladder and then I'm going to turn the thermostat back on.
So I just finished defrosting the left coil. I still got the covers off the TXV and I'm just getting in on this one getting in on the evaporators evaporators look pretty clean, but there's still some residual ice, so I'm just pulling the covers and popping it off real quick. I will say that this walk-in has one of these. I don't know what they call out there, like ECM motor controllers, that stage the evaporator fan motors.
They slowed down to a low speed when I'm assuming when the system's not calling and then go to a high speed when it's calling it's kind of weird. I really don't know how that thing works and there's not really any instructions. There is a sticker. I guess I could do some research on it.
Okay, so this is a troubling one, because I can't find anything wrong with the system got a clear sight. Glass refrigerant pressures are good. Granted I'm coming down to temperature still, but my TX fees are ranging from two degrees to ten degrees of superheat, both of them somewhere in between those numbers. I'd be happy with preferably eight to ten but, like I said it's still 45 degrees in this box. So the fact that they're, ranging between two to ten degrees, is pretty pretty good to me. I did find that there was a lot of lint on the evaporators, but the other thing I don't like is this controller they have on here. It's called a fridge, e-tec ec motor control from what I can tell it's got a sensor on the liquid side and the other side of the TX v, the outlet side, so the inlet and the outlet. So from what I can tell they're, probably looking for a temperature difference across the TX B to assume that the system is calling when the system is not calling for so much time.
The operator motors stage down to low speed than where they barely spend. Not a super fan of that because, when it comes to defrost, defrost is typically going to happen when the system's not calling, and I need those fans running at full speed to defrost properly. So you know I know. I said this looks like a refrigeration issue and it's possible, but the only other thing I could think of is this maybe but see it's hot right now, maybe if the system is low enough on gas or just barely low and the headmaster calls and might starve, You know when it's cool outside, but we really have only had maybe like two or three cool nights in the last two months.
It's been a hundred plus and then you know 85 degrees at the lowest at nighttime. There's been a few nights where it's hit. Sixty five, but that's very rare right now, so we will see things like this when it's wintertime, you know where you can't see the system not messing up, but then you'll come back on a cold morning. It'll be flashing.
You know now it that would mean that we don't have enough winter charge on the system, but I'm everything's working right now, so I'm just gon na tell him to keep an eye on him. Let me know that ice is up again, I'm leaning more towards that controller. They have, and the other thing that I don't like either is that controller is only on one box and then they have this conduit right. I mean on one coil and then they have that conduit running over powering the motors.
For the other side, I honestly don't see how much energy they're saving versus the cost of all these ECM motors. If I remember, I don't think the owner here paid for this. If he does the utility company paid to upgrade his system and put this ECM motor controller with ECM motors, I don't even get a dime for it, but I'm kind of leaning towards not being our problem, because if this thing stages down the low speed - and we Try to defrost you're, not theoretically, going to defrost all the ice off the coil, so it's just gon na have to wait and see our condensing units running fine or ready to clear side class. The other thing to the defrost clock, with holding time this afternoon.
I've had it shut off for a long time, but they have a bunch of defrost in the middle and I.
Good 👍 Chris
I always spot the completely irrelevant stuff, like the glass bottles of 7-up – retro!
Hello so what is the difference in restaurant Avs and office building and other building ACs?
I've always wondered why these "energy efficiency" things always target the fans in HVAC equipment.
It seems silly to focus on the fans, when the fans are such a relatively low draw as compared to the entire unit/compressor.
I would guess the defrost isn't on long enough. Only bottom defrosts and with those fans going, they probably are keeping the top half cool enough not to melt the ice.
That's assuming the ice was on top half of coil cause not sure if you mentioned where the ice came from, just that was half.
That's also assuming those ecm fan motors stay on during the defrost cycle.
Defrost timer?
Can you help me please. I want convert walk-in cooler to freezer.
ECM MOTORS IS THE MOST STUPID IDEA FOR WALKING COOLERS SO MANY PROBLEMS I AN IN THIS BUSSINES OVER 40 YEARS AND THIS STORY MAKE ME SEEK YOU SAVE 5 $ A YEAR AND THE CUSTOMER PAY SERVICE CALLS FOR NO RIZON( CON EDISON IDEAS) Service area Barrhaven??
we got a system like that at work
but we dont slow down the fan , when the room hits the target temp
all but one fan turns off ,
its just helps to move air around the room and helps to keep the room temp a bit more stable
the rooms we got at like 500 metric tonne rooms at -20c
a few reason why evaporator coil got iced up. mostly low on Freon.
or coil is dirty. fan moter did not work. TXV open too little. low pressure setting too low. thermostat fail to stop.ETC
when you have coil freeze up problem with enough freon.
adjust low pressure setting for cut out at ET 23F-25F cut in at ET 35F-40F.(ET is evaporating temperature) If you click my ID name you will see more inform..
Great video as always.
I mean if this happens a lot then why not ask them is it halfway iced up or all the way? Are you in Ottawa ?
Not to mention the fluffy ice.
I have also heard of walk in systems (especially in freezers) where when the system goes into defrost mode, the fans go off completely and a heating element comes on to melt the ice on the coils. I have observed that very frequently, the fans on some of the evaporator units in the grocery freezers at Sams Club are off. After doing research, I believe that those evaporators have a controller which switches the fans off and switches on a heating element to defrost the evaporator. Once the evaporator is defrosted, and it cools to below a certain temperature, the fans come back on.
hey sir plz tell how we can dfrozed a walk in chiller
I hate ecm motors to Are you in Barrhaven ?
Dude I hate ecm motors. If your trying to micromanage a function that should run at more of a macro function (full speed all the time) WIC a productive air defrost is imperative. All the trouble to save a few knickles or to feel warm and fuzzy over the environment.
That's one of the dumbest things I have seen doing hvac/r work. Slowing the fans down like that. I don't think that will save them very much by doing that. Design flaw for sure!
I have a walk in cooler which iced up only on 1/3 of evaporator close to TXV side (left side). The ice starts a couple of inches after TXV. Any ideas about the problem? Thank you Are you in Orleans ?
Yea but why does it need more refrigerant??? Woudint that meant theres leak in the system that needs repair ??
i notice the T-stat setting is around 33 F, it will keep the unit run a long time to reach and ice the coil.
99 percent of the time the drain line is stopped up
I got a question, what humidity level should a wic and wif maintain?
It's an air distribution issue across the Evaporator, either it's plugged from inside or rpm of each fan is different from each other, you can use anemometer to check fpm after defrosting the coil
Did you turn off condenser and run that temp control down to engage the ecm motors to defrost at full speed Service area Kanata??
Thanks for all the info and video really apreciate it Service area Nepean??
Dirty evaporators? Someone turning off the fan motors then forgetting to turn them back on?
Hi Chris. I would by pass the ECM. The fans could possibly be slowing down on defrost possibly. I have had this in supermarket refrigeration. Their are not saving a lot of money their. ECMs are great on condensers tho, especially in the winter to stop over condensing. 😊 Are you in Nepean ?
Hey Chris, I’ve seen systems where one ecm is the master and the remaining fans are slaves that take their control inputs from the master, the would explain the conduit between the coils. I think you’re on the right track thinking that there is a speed issue during or after defrost, not sure though. I’d love to see a follow up video on this when you figure things out. Thanks, good video.
Hey Chris,I would say its a defrosting issue..(not enough defrost with fans on low speed)..on defrost, moisture runs down coil block,defrost ends, unit starts and re-freezes moisture to give the pregnant belly ice block….if it happens again, possibly change the type of defrost timer so you can have a couple of 1/2 hr defrost during the day, an hour or 1 1/2 hr at night.. from what i know of EC fans, good energy savings in all uses..They are pushing them a lot in Australia.. we have high electricity cost..
IDK Could it be a chain reaction one Evaporator fails and the other Evaporator is on the verge of failing and thus a chain reaction.
I like this puzzler. Hope you post a conclusion to this. I'm new to the trade, & have only experienced one situation similar. High load because of weather, with swivel doors (a bagel bakery), and after thawing, system was normal. My service manager suspects 3/8" liquid line too small. My first run in with an EPR valve as well.
Thanks for sharing your experience and way to preach ice on coils! Service area Ottawa??
👍👍👍
i am not a fan of the ecm, twice the cost and double the problems. i would add electric defrost,plus like OC said check the compressor valves,either way not an easy call, thanks for posting this.
Maybe that motor controller is bad and slows the fans down when its not supposed to.
I get the tech,and efficient work of the ecm and it's all heading that way,but 90 percent of the time thats the prob,even on residential the ecm motors and the the controllers are the issues…nothing like a 3 speed..
A19ABC24C not very precise control. Etc111000 very precise control.
Maybe there is a way to rev down those evaporator fans on the normally closed part of the temp control. Ice like that is likely the fans reving down during the cycle
Slow draining and water hanging out in drain pan freezing up bottom of coil slowly building. Just a guess. Was it both coils at bottom or just one coil iced up like that? Looked like ice was thicker towards the entrance to the walk in from video as well.
I totally agree about the ECM controller how much possible power could be saved by spinning down the motors off cycle I always figured that in coolers the defrost occurred when the thermostat was satisfied and then the fans did their thing
Looks like that compressor ( at least on my iphone) Serial number is 2000 – lol. 18 year old compressor. Time to say good by to that old compressor. ill bet just a ice builder , never satisfies.
GRAN VIDEO CHRIS , GRAN VIDEO
That’s very interesting unit. I never ran into a unit like that would like to see one of these up close.
Air or heat defrost? I seldom get big chunks to fall off like that because they usually start freezing farther inside the coil.
Good vid !
Hey chris,
Its weird all those defrost cycles and the unit has soo much ice on the evap.did u check that when it hits a defrost cycle that the unit actually shuts off ? in this humidity right now u meed those fans at full speed to do your required air defrost. i dont know if u checked, but u may have a capacity issue here. did u pump compressor down and check the valves ? How old is compressor ? weak compressor , evaps hang below freezing , system never satifies, just builds ice. i hate those air temperature controls. i only run A421 digitals anymore & stick probe in the evap coil & control by coil temp. not room temp. those analogs are so innacurate it ain't even funny. Digital ftw. Wayy better control.
Those frigitech units came out here in the early 2000’s. Needless to say most have been removed. 👍
Looks like txv is not feeding properly, all ic3d up at the outlet. Ecm motors save a lot of energy when installed properly. There is a fase out of induction motors going on at this moment. All motors above a certain horsepower are not allowed to be imported here unless it meets high efficiency standards (ecm).
Interesting system really enjoy the videos.👍👍
Had one ice up similar to that on a system they shut the fans off when the room reaches temperature.
If I'm not mistaken there's probably sensors mounted one on liquid and outlet… Oops you mentioned it