HVAC 098 ΔT Delta T Delta Temperature 

ACCA Manual D and ACCA Manual T are all too often overlooked and misunderstood. Bad ductwork and airflow is a massive problem across the nation.

Tell me about it!… :) I’ve completely re-done several commercial and several residential projects this year only… people are alway very surprised with BEFORE and AFTER differences. Most of the times convenience store and small restaurants report $400/$500 drop in monthly electric bill…

It give a better more accurate temperature reading. The dirt, scale,, corrosion and derriere work like insulators not reading the temperature of the copper as well.. you may end up with more air temperature the. Copper/fefregerant temperature. Some of the new clamps use the copper itself as part of the temperature so conductivity is a must. They even send sand cloth with those clamps.

I will see if I can do that.

@@love2hvac Thank you! 🙏

you only have one manifold? I use one for r22 and one for r410A. for AC checks I use digital probes.

The problem is looking at pressure. You need to be looking at superheat and subcooling. Also delta t and TD

Externally with dirt preventing proper airflow. I will go into more detail when I get to condensors fans. A propeller style blade is not great at moving air under pressure. Once the air is restricted the blade struggles to move air. The reduced volume of air ends up being slung to the edges of the blade and out the top side.

No one example I cave the delta T was 15 and a other example it was 30.

Yes sir

ru-vid.com Has some great videos on ductless units.

18k BTU is 1.5 ton (12k BTU per ton).

@@Elisummit845 that is correct but what size of motor ,if I put to large of motor the suction pressure will be to low, and to small the head pressure to high or maybe the motor will stop ,running to high

That gets challenging. I open the back of the motor and count the number of windings. There will be 2 sets outer and inner. Go with one and count the number of poles (loops) it will either be 6 or 8. 6 pole motor will be 1075 rpm 8 pole motor will be 850 rpm Next will be horse power Pull the rotor out and measure the stack. The darker gray bars on the rotor, look like angles bars. 6 pole motor 1.25" = 1/4 hp 1.75" = 1/3 hp 2.50" = 1/2hp 8 pole motor 1.25 "= 1/8 HP 1.38"= 1/6 HP 1.75" = 1/4 HP 1/3" = 1/3 HP a universal motor will be reversible. Set it so it turns as the blade catches air. Concave curve cuts into towards the airflow.

@@love2hvac this is some massive information I will definitely write down 😊. I could have used this many times. Thank you

It's not entirely accurate way but it's something when you have nothing.