ACFM vs SCFM 3D

Рет қаралды 30,736

Күн бұрын

In this 3D video, we show the differences between ACFM vs SCFM, also known as actual cubic feet per minute and standard cubic feet per minute, respectively. Both are means of quantifying airflow, but they show the difference between mass flow rate and volume flow rate.
CFM represents cubic feet per minute, which can represent a 1’ x 1’ x 1’ box of air. The blower moves hundreds of these boxes per minute. That air may have varying temperature or humidity levels. The standard CFM (SCFM) conditions consist of air at 68.3 degrees Fahrenheit and 0% humidity at atmospheric pressure. A cubic foot of air will weigh 0.075 pounds under these conditions, but this weight will change when there are changes in temperature, pressure, and humidity. HVAC systems also move several boxes of air, with each one exerting force on the others.
The air we breathe primarily consists of nitrogen (78%) and oxygen (21%), plus some trace substances. These molecules move faster when we apply heat, making them more spaced out and less dense, which reduces the weight of a cubic foot of air. Water vapor (humidity) weighs less than diatomic nitrogen and oxygen in the atmosphere, so higher humidity levels will reduce the weight of a cubic foot of air. Lower pressures, such as at high elevations, will make the air less dense, which will also decrease the weight of a cubic foot of air.
For those reasons, the 400 CFM per ton rule of thumb is not applicable to all climates. We want to focus on maintaining a fixed mass flow rate, which accounts for the weight of each cubic foot of air. ACFM accounts for the weight of the air we’re moving to account for variations in humidity, altitude (pressure), and temperature. Arid climates are likely to have higher target ACFM rates, and humid climates are likely to have lower target ACFM rates. SCFM is a common reference point during the commissioning and testing of equipment, and ACFM is more likely to give us a nuanced idea of the pounds of air our systems are moving.
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Пікірлер: 30

@johnstonecg Жыл бұрын

Should be taught in every class

@bikerbobcat Жыл бұрын

I know these animated videos cost more in time and production, but for visual learners like me they are super useful Top notch work as always y'all.

@christopherbarrett6408 Ай бұрын

Your teaching is so important and exciting. I have been learning so much from you. Thank you

@AARONJL92 Жыл бұрын

Really enjoying these animations. Thank you for all that you're constantly teaching me.

@raymondjatta9673 9 ай бұрын

I can't thank you enough for this well narrated 3D video which gave me the opportunity to understand the refrigeration side of the trade.

@ldero9520 Жыл бұрын

As a retired AC tech and former teacher, I m giving a 10/10 for this presentation

@chekelley6861 Жыл бұрын

I’m not in the HVAC industry but I learn so much watching your videos. Great job.

@briantagg2678 7 ай бұрын

Another fabulous video on this new format! To coin the old phrase... You've come a long way, baby!😊 Thanks for your untiring efforts, Mr. Orr! We will all be better as a result of your energy. Thank You.

@swank1975 Жыл бұрын

I love the new graphics package for these videos. Top notch!!! Keep up the great training info.

@dakotab825 Жыл бұрын

I am very much a visual learner and struggle with text book studying. Thank you for taking the time to make such a great video.

@texture6 Жыл бұрын

The automation is out of control 👍🏻🤘

@HvacRooster Жыл бұрын

Thanks so much for the video really helps understand this a lot better

@abdolkarimmehrparvar6583 Жыл бұрын

Was amazing. Thanks for the informative contents.

@dnaheatingcooling8157 Жыл бұрын

Great content as always. Thanks for all of your hard work on behalf of the hvac-r industry.

@lucasrodrigueseng 9 ай бұрын

Best explanation ever! Thanks

@jcstutorials3090 7 ай бұрын

Great work! Thank You!

@brianmcdermott1718 Жыл бұрын

Great science info. Thank you Bryan.👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍

@Noel-pz9zc Жыл бұрын

Air distribution was a very boring class when I was in school , But it's a very very important part of our trade . It can make you or break you as a Technician .

@kyleswim99 Жыл бұрын

Fantastic video and explanation

@jleonardoperez5402 Жыл бұрын

These videos are awsome🎉

@Nikdas147 Жыл бұрын

What a presentation 😮

@MundoHVAC Жыл бұрын

*EXCELENTE* Gracias y saludos

@chevydavidson9220 8 ай бұрын

So why don't companies make a variable unit that senses the humidity of the incoming air, the elevation of the unit, and temperature of the incoming air and adjust to hit the same pounds of air per the programmed inputs. Takes the human factor out of the equation. Great Video!