Charging a Heat Pump in Heat Mode
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- čas přidán 1. 06. 2024
- Do you need to know how to charge a heat pump in the winter? This video about charging a heat pump in heat mode is just a quick demonstration of what to do when the weather is below 65 degrees outside.
We show a Carrier chart for checking the charge in heat mode; manufacturer information will always be one of your most helpful tools when checking the charge in heat mode. In this case, we check the indoor dry-bulb and outdoor (wet-bulb preferred) temperatures to find the corresponding suction and head pressure ranges. Note that lower outdoor relative humidity also results in less defrost.
Many times, it's best to weigh the charge and then use the manufacturer's chart, especially if the system has a known leak or long lines. When charging from scratch, ALWAYS try to weigh in and then use the chart.
When connecting gauges, connect to the always-suction port on the low side. On quite a few systems, you can get your head pressure on the liquid line, but some systems may require you to connect to the discharge line to check the head pressure.
A common rule of thumb is the 100-degrees over ambient rule; the temperature of the discharge line on a running system should be 100-110 degrees above the outdoor air temperature. Higher temperatures may indicate an insufficient charge or a restriction. There is also an evaporator DTD rule of thumb that states that your suction saturation temperature should be 20-25 degrees below the outdoor ambient temperature. The CTOA rule of thumb states that the CTOA should be 30-40 degrees above the indoor dry-bulb temperature. You can also check the system without gauges; using non-invasive temperature clamps on the suction line takes DTD and superheat into account. Indoor delta T values will vary wildly.
Overall, the design conditions in heat mode vary a lot more than they do in cool mode, so you'll see those wider ranges of variations reflected in your readings.
To learn more, go to hvacrschool.com/checking-char....
Read all the tech tips, take the quizzes, and find our handy calculators at www.hvacrschool.com/
Really enjoy the podcast, I’m traffic for 3/4 hours a day love being able to hear different perspectives and theory in the trade while wasting time driving, thanks for everything you do and congrats on getting Eric m lol
Thank you so much for your two different rules of thumb the 110 over outside ambient as well as the 20 to 25 under outside ambient....8 years of not really having a real thumb for a heat pump and you gave it to me in 10 minutes thank you very much
That was a lot of info to digest.
Thanks for the video. here is what I've got: 1- probably just enough knowledge to be dangerous. 2- A 17 year old 3T 410A Carrier HP. 2 yrs ago, and with some help, I replaced the blown out evap coil and added a new charge. 3- I've been checking pressures and temps on darn near every section and subsection including Suction and discharge pressures and temps as well as return and supply air temps at the air handler. 4- during the summer I believed (and still do) that the unit was low on charge. I added small amounts 2X without having a scale. each time the temp differentials across the coil got much better. 5- Outdoor ambient is currently about 35 deg. with the digital thermometer on the discharge side I am reading up to 114 deg. I checked the suction side and got about 80 deg. 6- pressure for the discharge side read about 350 chart from unit shows it should be about 320. at this point I truly can't figure out if the unit is over charged or undercharged. In that the only tools I do not have are a proper scale and vacuum pump, I've been hoping that my research would reveal this mystery but no such luck, yet Thoughts?
Hi Bryan, great video! Would this procedure still apply on a Modulating (inverter comp) Split System Heat Pump? If not, what would you change in your procedure?
You guys are the S$@T!!!!! CONSTANTLY LEARNING
Hard to get a suction temp in the heat mode?
Do you have a video on how to charge a 410a mini split heat pump in cold weather.
Looks more like 10~15 psig over ambient temperature on the suction pressure, according to the chart.
How often do you have to adjust the TXV or the charge based on superheat after using the weigh in method on a new install?
Never adjust a TXV
Love the info, can you send this to me or where can I get this information
Where do we obtain the paperwork you're referring to here? Thank you!
Good question ,
Oh, do you ever rest?
I thought this was going to be how to add refrigerant on a cold day with the unit running in heat mode and where to hook up and where it’s going in at but it was technical 😕
Zach Wood yes this one is for people who already know the basics
Bro do u work on units are u a paper guy
I would like to see a non advasive heat pump check video.
too fast for me
I thought I was going to see a system get charged... ???
This guy is a moron!!
You talk to Fast.
As a new technician, hearing things like, "obviously" and "goes without saying" is not helpful. The trainer in this video is WAY too fast. Throwing information in like everyone should understand is demeaning and useless. I have to pause this video 100 times to get the general idea. Not impressed and moving on.
Agreed. Lots of good information, but it's glazed over so quickly that I wonder if I'm even a competent service tech haha
ENTRIFICE if you know the basics it’s common sense dudes
Totally agree. Presenter goes way to fast. Bet no novices were consulted in making of video. Too hard to follow.
These videos are geared towards the experience tech, not a newbie training video.
Talks way too fast to really understand. Not really one of his best instructions.