I appreciate you being so thorough with everything you teach. I just bought your workbook. I went to school to get my epa universal and achieved that. I've learned more from you then many others
Special Thanks to Brandon for all the editing and design changes to make this video possible! We are now on Facebook! facebook.com/acservicetech Follow and Like our page on Facebook to get unique content and updates posted every other day!!
Looks good. The only thing I do above this, is an additional ball valve that would fit between vac gauge and machine port. The purpose being to do an immediate pump and gauge test within the first couple of minutes. I get to see my gauge drop right below 50 or even 20 micron. Not just 500. Helps test the hoses for leaks also
@@acservicetechchannel When you do write it, will you please make sure to use the glossy pages exactly like you did for the other book? It helps a lot with durability and readability. I'd rather pay an extra $20 for that type of paper.
Nice to inform techs about the non running pressure check. But it's not "air" freezing on the coil at 32F. Also, I tell my trainees that it should be between outdoor and attic (if it's in the attic) temp as they are usually not the same. Thanks, though!
Thanks for the info Craig! Quick question though, if indoor temperature is a different temperature than outdoor temperature, how much of a difference will that vary the pressure to temperature correlation? So for example i put my thermometer on the outdoor unit and measured 70F outdoor ambient temperature but indoor temperature is say 73F, will this effect pressure temperature measurement? And is there a say a range +/-5 degrees? Thank you for your time!
How much refrigerant pressure must still be in the system to do a proper pressure test ?? on low and high side. Would you add a little refrigerant for the test etc etc Thanks
That’s why I have owned a refrigerant identifier since 1994 you would not believe how much contaminated refrigerant there is out there either mixed with other refrigerants or high percentages of air.
If there is a restriction in the system n the unit is off what pressures would u read on hi n lo sides ? I thought if there was a restriction n the unit was off then the static pressure would b low n not reach ambient temp. This is for commercial refrigeration units like walkin n reachin coolers/freezers.
Is It your book teach how to check the gas for the air-con, inverter systems, 1 compressor can use for 2 unit,3units,4units.... Because her in Singapore all ppl use system inverter, and the air-con have just LP for you can top up the gas. I already see the video for Mitsubishi inverter, but they dont show the details
Colin, I apologize for the shipping price to Canada but there just doesn't seem to be anything we can do about the price to get it over the border there at this present time, especially with Covid and trying to maintain fast shipping times. There are bundles available on the website at www.acservicetech.com/store that include fast shipping. We also have the ebook available on our website and on google play that is less expensive, thanks!
So when checking charge with the system off assuming outside temperature is 85 and inside temperature is 72 does that mean I’m looking for 78.5 saturation equalized pressures at my gauges?for a charged system?
It will more closely match the outside temperature and it will depend on how long the outdoor temp has been that high for. So to put it into a real world situation, when I walk up to a system thats very low on refrigerant and off and equalized, when I read a sat temp on both gauges lower than what the indoor temp is, I know somethings wrong because the indoor temp is usually lower than the outdoor temp. Either the wrong refrigerant is in the system or more likely, it has lost all the liquid and there is only vapor left. Thanks a great question!
If it seems close to normal the only way to tell is by running the machine. That's because you can lose over 3/4 of your gas and static /resting pressure remains the same. On cooling low pressure will drop like a stone
Hi, Mister Craig my name is Nelson. I was checking an r-22 heat pump system with txv in the air handler. I used the subcooling method 250 psig, 91F temp.t1 the first time. I added the inf to the measure quick app with an 11target subcooling, cause I couldnt read the data plate and the app said that I had to remove refrigerant. However, the blue gauge showed the saturated temp. between 32, 33. also, I measured Delta T and it was 47. something on supply and 71 on the return, but 24 is higher than 18-21. So, my question is if Can I remove refrigerant from the system with the blue gauge on that number?
How are you figuring an iced up coil low on refrigerant due to low subcooling where the coil is totally iced over that uses a fixed metering device tev yes understood but a fixed metering device goes against what I have read and told by many
We check the charge with subcooling on systems that have a txv and systems with a fixed orifice with total superheat. However, even if an evap coil is frozen over with a fixed orifice, a system will still have some subcooling. If the subcooling is only 1 degree while the coil is frozen, then the system is going to read as low on refrigerant when checking with total superheat after you defrosted the coil. If it had say 5 degrees or higher while the coil was frozen, it could go either way and you could melt the coil to tell and check with superheat.
Hi ac service tech :) im a fan of yours from the Philippines. Im more of a diyer and been researching about the problem of my 2 horsepower mini split AC (LG HS-18ipm inverter ac model number) Can i ask about your opinion on what may be the problem of my AC system? Thanks I am experiencing icing of my evaporator everytime my condenser (outdoor unit) gets a THOROUGH cleaning (i installed a watt meter on my ac and when the consumption hits 1,100 watts ice slowly forms on the evaporator). Icing happens when i set the thermostat to 24 degrees celscius or below BUT here is the contradicting problem. When for example my condenser or outdoor unit hasnt been cleaned for like 4 to 5 months it is very dirty and almost clogged, BUT, i dont experience any icing on my evaporator (indoor unit) and cooling is excellent and working fine, i can even set the thermostat to 18 degrees without icing (consumption on the wattmeter registers 2100 watts) What could be the problem? The ac technician who handles my AC servicing couldnt give me a clear answer. Hoping to hear from you soon. Thank you! Godbless
First of all let me tell you that you really know your stuff and Thank you for all the videos and good information. Now a constructive criticism in my opinion you talk to fast and try to jam to much info by repeating to much .
at ~1:00 "Saturated Temp should match surrounding air temp". Lost me here. Why should sat. temp = air temp when system is off? (I watched the sat Temp basics, but did not see this point addressed).
Not exactly and no you cannot measure the charge with the subcooling method with fixed orifices. However, in the event of an evap coil that is fully frozen, if the subcooling is between 7 to 15 degrees, this tells you that you are not severley undercharged with refrigerant. Thats all. Its just a quick method to know whats going on. If subcooling was 0 degrees with a frozen evaporator, you would know that the system is undercharged.
You can purchase it through our website at www.acservicetech.com/ac-book or through www.amazon.com/shop/acservicetech and the E-book is available at google pay store and our website, thanks for your interest!
I recently got back into HVAC (after being a Electronics, radar, power generation and high voltage experience). My new HVAC mentor instructed me to check the HP saturated pressure, then check my app and add 30 degrees to the ambient outdoor temp to the app to get the applicable super heat refrigerant pressure to determine if the system is low or high on charge. I have found this is bad idea, heat every HVAC tech I have met uses this method. WTF?
First tip is incorrect, in refrigeration 10g or 1kg of same refrigeration at equilibrium has same pressure, doesn't matter the weight. Please correct that in your slide
Immigration Freedom. The pressure would remain the same in a system or bottle as long as the refrigerant still had some liquid left regardless of the weight. If it has liquid and vapor present, that is saturated. However, I am explaining when so much refrigerant leaks out that there is only vapor left, the pressure will be lower. Due to the availability of space in the tubing I often find about 7/8 or more of the full refrigerant charge has leaked out. If the charge had only leaked a little bit, the pressure in the system would have remained the same because there is still liquid in the saturated mix. This is an odd scenario that no one seems to talk about so I thought I would throw it out there. Check out the other video on saturated temperatures. The link is in the description section of this video, thanks!
Keep in mind, this IS NOT for the average d I y guy. You need to have some formal training before attacking a refrigeration issue. Also must be certified to handle refrigerants.
Absolutely, you must be EPA 608 certified before handling any refrigerants. These HVACR training videos are primarily focused toward those in HVACR school and those in the HVACR and maintenance trades, thanks!
Well before say 1990 it was simply the average person's simple easy task. Ie folks topped off ac units in cars in window units and central air units. There were not even any recovery units or recovery tanks then. A 30 lb jug of R22 was 25 dollars at the local NAPA store. In Window units the bigger ones came with instructions on how to add refrigerant. Maybe in 30 years one will need an EPA license to change the oil in a mower since regulated? :) Pre EPA refrigerant rules the 30 LB jugs of R22 or R12 etc were two way valves. Ie one could pump back good R22 into a used R22 tank to reuse the Refrigerant after doing repair. Later the valves hit changed so one cannot do this with an old tank. Pre say 1990 EPA rules the common then R12 12oz and 14oz cans were used for air horns on boats and for ball games. Also for toys that shot BBs. Eons ago the cans were 50 cents each when gasoline was 33 cents. In automobiles an ac unit can just have a slow leak in seal in the compressor. Using it every month helps keep the seal healthy
