This video is about fan, efficacy and fan. Efficacy is simply CFM, / watts, I'm gon na give it to you right off. The top vana efficacy is CFM divided by what's just a very simple ratio of watts to CFM. California requires that you must have at least a point: 5/8 fan efficacy.

Now, when we say fan efficacy, we're talking specifically about the blower, so the fan then moves the air around the inside of the building, not the condenser fan. So it's fan efficacy of the blower motor and so in measure quick, for example, they show fan efficacy as part of the measurements you can take if you are using a power meter such as the redfish idv m5 50, which is the meter that I'm using in My demonstration here you use that to measure the wattage, which is simply volts times, amps times power factor in order to get that those watts and that's actually very important when doing this. The power factor piece, because many of these blower motors have very low power factors. That's just the nature of a lot of ECM motors, so you have to take that into account if you're gon na get a true wattage number.

So again you take the CFM that the blower is producing, and then you divide it by the watts, measured with a power quality meter, like the redfish meter shown now. That's one piece of the equation, but the most challenging piece of the equation is actually figuring out. What CFM is the equipment producing? Maybe if the equipment is new - and you know exactly how it's set up - you can go to the fan tables for this piece of equipment, like the one shown for the unit that I'm working on and you can go across, find the static pressure and figure out What the CFM is, and generally that's going to be quite accurate, so long as the system is set up exactly as specified in the fan tables, and then you also have to take into account if the thing has gotten dirty or anything exchanged with the operation of The equipment you've got to take that into account. If you don't have that ability, then you have to use something like the true flow grid from the energy conservatory or you have to do a duct Traverse or maybe use an airflow hood.

All of these things can be quite challenging to get your CFM measurement. Some people will talk about using the temperature rise equation with electric heat or gas furnish those have their own challenges, which I've talked about a lot on the podcast. We're not going to go into that, but, ultimately, in order to do this properly, you have to both have correct wattage, which requires being able to measure what is directly and also taking into account power factor. You can't just do volts times, amps on a motor that does not equal wattage on a motor, because you also have to do that volts times, amps times power factor, and then you have to know your CFM once you have.

Those fan. Efficacy is quite easy to do, but that's challenging to get in the first place, which is where measure quick does make it a lot easier because it brings it all together and gives you that fan efficacy and again, like we mentioned a point, five eight or better Fan, efficacy is really what you're looking for and that just simply means that you're moving a thousand CFM for five hundred and eighty watts. If that's what you were moving so very simple math in that way, and so, if you put in less wattage to get the same CFM, that is a more efficient or effective, which is really what efficacy comes from. It's a more effective blower in both the case of PSC afirmative, split capacitor and ECM electronically commutated motors, in both cases when that blower wheel gets dirty or when that of Aperta coil gets dirtier in both cases.

They're going to it's going to affect the efficacy of that motor in the case of the ECM motors that we see more often today, the way that it's going to affect it is because, as that motor attempts to maintain that constant torque or airflow output. So as it becomes more restrictive and it's ramping up in order to attempt to produce the same airflow, it's gon na, do it at a cost of higher wattage. So as that wattage increases in order to do the same amount of work, that fan efficacy is going to decrease. So it is a useful thing to look at and it is going to tell you you know.

Is this: how hard is this thing working from a wattage standpoint in order to produce the desired CFM? So this is the easiest way on a new system to find the airflow, as I'm just gon na enter the product number go down to the product data all right, so we've got our airflow delivery chart. This is just the basic one, and you'd really need to check the static pressure to make sure you were in the right zone. So we have the zero zero two and it's the o2 four. So if you go over, you see nominal AC cooling, 700 CFM.

If you want to get more advanced, you can go down into the fan. Charts you can see. The acceptable range is from point two, zero. Two point: four.

You can look down at the fan curves here. This is for the zero zero two and if you have the o2 four, you can see that we maintain pretty much the same. If you look at the look at the cooling airflow, it's that solid line you can see it stays pretty pretty much right at 700. All the way up to 0.6, and then it starts to drop off this system here generally learns about 0.3 external static as measured before.

So if you, if you want to use your fan, charts, that's the way to do it. Otherwise, you can do a duct reverse or something like that. Nice, I'm gon na pull up measure quick connect, so we are connected here. We've got a hundred and eleven watts, like I said, we've already calculated on this unit that it moves when it's in full speed, non dehumidifier mode.

It moves about seven or CFM right there about, since I've already manually entered that so 1.1 amps. If you just took amps times the volts you'd, be about double that wattage, but because it's multiplied by this power factor which is very low on ECMs 0.46. That's where we come up with that 110 watts. So if you were to just do volts times, amps that would be VA, not wattage.

You can see here. This is milliamps, so it's 1.1 3 amps, I'm interested Rumi accurately, and this is a 208 building. So that's where we have the 213 volts so now all we have to do we'll clear it and just can't recapture it capture that data. So now this data is captured.

Now, if we go back see our fan efficacy, it's a point 1 6, which is very efficient so for the seven hundred CFM it's running, it's doing it very efficiently. Now that power factor does factor into total circuit load because the amperage is still higher. But if you were to just have measured this with a non power quality meter, you would have thought that your wattage was significantly higher than this because of not taking into account the power factor. So it's important that you measure your airflow accurately and you measure your wattage utilizing volts times, amps times power factor in real time.

So that's fan efficacy, thanks for watching.