I'm looking for the most accurate and informational charts in order to obtain correct Subcooling, Superheat, static pressure, and Delta Ts for R-22, 410-a, orifice and TXV type systems. Do calculations differ if it is an Air Handler or A-Coil atop a furnace? Any good info out there that I could carry around with me during these PMs? Thanks!
most of that stuff is gonna change depending on the environment....ie superheat will relate to your IndoorWetBulb and OutDoorDryAir. Your Delta T will depend on humidity. The Subcooling will usually be defined by the manufacturer. Static pressure is gonna be affected by a few factors, but will again be dictated by the manufacturer (approx .5")
get the digital gauge like fieldpiece sman3. I just got mine and I am starting to forget how to calculate superheat and subcool. :-). J/K. typically you can buy the chart at the supply houses or try searching online. To determine the values, you have to refer to the manufacture spec.
Most of that list is going to be provided for you by the manufacturer....but you can become a pro member and learn a lot on the Educational forums here.
Originally Posted by bostonB
HVAC Buddy on Android market
Bitzers is a great pt chart also on Android market
Sent from my ADR6350 using Tapatalk 2
I don't think the poster is trying to learn how to figure superheat, he's trying to get schooled on knowing what numbers to shoot for when testing or charging a unit...
and I agree, it's all in the installation instructions of the equipment.
The TRUE highest cost system is the system not installed properly...
Do you go to a boat repairman with a sinking boat, and tell him to put in a bigger motor when he tells you to fix the holes?
I am yourmrfixit
My son the plumber asked me what the A/C gauges should read.
I asked him
What type of metering device?
How much load?
... after about the tenth question he walked away in disgust.
Your gauges and meters are your eyes into the system, experience will determine how much you can know from what you see. I just got a set of digital gauges with the super and sub cooling clamp on probes ... still find myself pulling out the PT chart .. especially when I put the subcooling probe on the suction line and vice-versa.
Rules of thumb .. you want evaporating temp 15-20 degrees below the temp in the conditioned space and the condensing temp 15-20 degrees over entering outside air.
Subcooling tells you how much liquid is stacking in the condenser.
Superheat tells you how far away the liquid is from your sensing point.
Actual numbers will vary due to operating conditions and type of installation.
You can download this book it has a superheat, supcooling and TEET charts, its FREE
FREE articles on Superheat, Subcooling and A/C Troubleshooting. For the FREE downloading of the articles go to Book and Papers on HVAC on the main page, put them in to the cart then, you must click on the PRINT AND CALL button for payment at check out. This method allows me to process your downloading at NO CHARGE
Actually want a evap temp 25-40 below ID DB.
Cond temp 10seer 20-30 over ambient.
13 seer up 10-20