So glad I'm out of the residential field I'd be the one to go back out after someone charged to gas a unit up and I go back to remove a dirty filter or tell them their coil is dirty.
checking these pressures and temperatures at the compound gauge,. first when refrigerant was added and sub cooling went up, but the super heat stayed the same, including the low suction pressure did not increased meaning you have a liquid line restriction , or txv problem,
That is a little low as well. Txv? You’re lsat is like 3 degrees above outdoor. Should be 15 minimum 8 degrees subcool. You’re VSAT will go up and low side. The indoor temp of 78 will not effect that maybe 65-68 degrees indoor would
Txv indoor and the charge was spot on per charging table. Every system has a different subcool and superheat target. The indoor temp was 67 degrees and the return air temp was even colder due to a portable unit installed next to the return air. The homeowner wanted it cold. I see you didn’t watch the whole video based off of your comment 👍
The issue ended up being that he had a portable unit sitting in front of the air return so the return air temp was 57 degrees 😂. The guy was from Wisconsin and wanted it freezing cold in the home. I like my house cold but this guy was on a different level. The air flow was spot on. The static pressure across .06
@@ironshieldheatingair5751 I have never seen or ever heard of static pressure reading of .06 in my entire career. That is basically no static pressure at all. .6 I can buy and see all the time, but .1 or .2 is hard enough to achieve with the newest systems. The rest of the video I am onboard with. In Colorado, everything is de-rated, so we have to adjust charges differently. But that SP is hard to believe.
To address a low VSAT (Vapor Saturation Temperature) reading, which is an indication of the temperature at which refrigerant evaporates in the evaporator coil, you should consider the following potential causes and corrective actions: Potential Causes: Low Refrigerant Charge: Insufficient refrigerant can cause the evaporator coil temperature to drop. Dirty Evaporator Coil: A dirty coil can restrict airflow, leading to lower temperatures. Restricted Airflow: Blocked or dirty air filters, closed vents, or obstructed return air can cause reduced airflow over the evaporator coil. Thermostatic Expansion Valve (TXV) Issues: A malfunctioning TXV can cause improper refrigerant flow, leading to incorrect temperatures. System Overload: High indoor humidity or excessive heat load can cause the system to struggle, affecting the VSAT. Incorrect Superheat or Subcooling: Improper superheat or subcooling settings can indicate an issue with refrigerant flow or charge. Corrective Actions: Check Refrigerant Levels: Verify the system has the correct refrigerant charge and add refrigerant if necessary. Clean the Evaporator Coil: Ensure the evaporator coil is clean to allow proper heat exchange. Inspect and Clean Air Filters: Replace or clean dirty air filters to ensure adequate airflow. Check Airflow Path: Make sure all vents and returns are open and unobstructed. Evaluate TXV Operation: Check the operation of the TXV and replace if it’s malfunctioning. Check for Air Leaks: Inspect the ductwork for any leaks that could be affecting airflow. Assess Load Conditions: Ensure the system is not undersized for the cooling load and check for excessive humidity or heat sources in the space. Adjust Superheat and Subcooling: Make sure superheat and subcooling levels are set correctly according to manufacturer specifications. Steps to Increase VSAT to 34 Degrees: Ensure Proper Refrigerant Charge: Add refrigerant if the charge is low. Improve Airflow: Clean or replace air filters and ensure all vents and returns are clear. Clean the Evaporator Coil: Remove any debris or buildup on the coil. Inspect TXV: Make sure the TXV is functioning correctly and adjust if needed. Check for System Load: Reduce any unnecessary load on the system, such as high indoor humidity or heat sources. By systematically checking these potential causes and making the necessary adjustments, you should be able to raise the VSAT to the desired 34 degrees.
How cold is he trying to keep the inside? Someone told me that your central unit can only cool 10 to 15 degrees below the outside temp. I dont know how true this holds. I prefer window units i can get my bedroom about 68 degrees on a 100 degree day. But my bedroom is on the north side. He needs a freeze protector stat on the evap coil. Its wired in with the 24 volt contactor in the outdoor unit so if it detects freezeing conditions on the evaporator it will shut off the condensor blower will run till frost melts, and outdoor unit will restart again. I worked on a trane unit that was set up as a low ambient unit to cool a server room, and it had a freeze protect device on the evap coil.
I’m anxious to see the answer to this. Just installed $15k system sep-2023 that can’t cool my house below 82 degrees when it was 98 outside. Feeling pretty scammed.
A freeze stat should be standard on all systems in my opinion. But a properly sized air conditioner with proper ventilation in the attic space where the duct work is located should keep the home 20-25 degrees cooler than the outside temperature. A slightly oversized 2 stage system is the way to go in Florida in my opinion so it can ramp up on the hot days and ramp down on the mild days 👍
@@ericnewton5720that’s 100% on how the install was performed. Something’s definitely going on because I’m a hvac tech myself and I have a 20 year old r-22 system that works perfect on 95 degree days . Something’s going on there w
No, I wrapped it up. The homeowner had a portable unit sitting in front of the air return causing a really low return air temp. The home was 65 but the return air temp was 57 degrees. Causing a freezing temperature evaporator coil. The filter was clean and the static pressure was .06 😎
Yessir, been building and haven’t had the time to make any videos in a while. I realized that my techs could use these for training so I’ll be making videos and posting them here. Thanks brother, glad to be back
Interesting how MVAC testing is so different. In MVAC, the manifold gauge tells you everything. Superheat and sub cooling isn't calculated. Charts are very common showing operating pressures at different temps and humidity. As well as vent temp.
@@ironshieldheatingair5751 disagree with you charge is low. Superheated is to high at them conditions and subcooling is low . That tells us to little refigerant on low side to little on high side what does that indicate? Sh 20 Sc 3-4 to low .
@@robertcherry4971 That is what I am saying as well. That unit is low on refrigerant. If your refrigerant is superheating 20° with a low inside temperature you're evaporators clearly starving for refrigerant, and I can't speak for anybody else but i have never seen a recommended subcooling of 3. The general guideline I have always been taught was subcooling between 7 to 12 degrees, and from experience I can say manufacturers want their equipment to be in a range of 10 to 13. Also it is entirely too cold outside for him to be adjusting refrigerant. His liquid saturation is 100° so his outdoor dry bulb temperature is probably between 70-75 degrees.
