Upgrading Blower Fan / Motor.....More Power! = More Flow

[@HODGEPODGEDODGEGARAGE]

Nice work Andy! 😎👍

[@FlatThunder]

Thanks Zane! This isn't my favorite content, but all in all part of what consumes my time. I had Margaret out the other day cutting a lap around the block. Thanks for watching! 👍😁

[@ToIsleOfView]

The BTUs are the same for heating and cooling. You are pushing more air, so the cooling air temp will be several degrees warmer and the heating air temperature will be several degrees colder. The room temperatures will be better controlled in the distant rooms if the duct work is sized for the extra CFM supply. Some duct work has too much restriction for the extra air to reach the end of the duct rooms. Instead, more air will come out of the vents close to the blower. Depending on where the tstat is, the extra air may satisfy the tstat quicker.

[@marstedt]

More flow = more thermal transfer ie. More heat from the furnace, more cool from the AC

[@billygilbert7911]

But can your heater to heat the air at the higher CFM?

[@FlatThunder]

Good question! I will test the higher air flow when we switch from cooling to heat mode. I'll have a smaller pulley and the shorter belt prepared if a change is required. Thanks for watching! 👍😁

[@marstedt]

The answer is yes. The more airflow the more thermal transfer.

[@billygilbert7911]

@@marstedt My concern was a reduction in rise and causing it to take longer to heat causing longer run cycles.

[@marstedt]

@@billygilbert7911 A "reduction in rise"?

[@billygilbert7911]

@@marstedt With the increased air flow across the element if it was rated for a 10 degree temperature increase at 400 cfm, and the cfm was increased to 500 the rise should be less than 10 right? I'm probably using the wrong terminology.

[@Steve-sg3uz]

I live in a very humid state and lowered the direct drive blower motor speed in order to make the A/C dehumidify the house. Now I am under 50% RH. Also keep in mind that when you raise the fan speed it's like running your hand across a candle flame quickly. Less heat is removed.

[@FlatThunder]

Good points! The CFM increase / blower speed increase was required for this unit to push the cold air out the registers more. It worked before the swap, but the thermostat could barely make temp. The unit would run too much and the cool air was trickling out of the vents and settling at floor level. The increased flow pushes the cool air up and then it settles down. Heat mode might require a speed adjustment..... Thanks for watching and sharing! 👍😁

[@marstedt]

More flow = more thermal transfer ie. More heat from the furnace, more cool from the AC

[@Steve-sg3uz]

@@marstedt Take your hand and move it quickly across a candle flame and then slowly. Which is going to transfer the most heat to your hand? In my area there are a lot of older water to air AC units. If the water coming out is too hot the flow is too low. If the water is not even warm the flow is too high. Rule of thumb is a nice warm water coming out is taking away the most heat efficiently.

[@PaulPassarelli]

you wrote: "...it's like running your hand across a candle flame quickly. Less heat is removed." That's not true or correct. The _HEAT_ flow is the same. The *TEMPERATURE* change is less.

[@Steve-sg3uz]

@@PaulPassarelli Correct. The air will have less temperature change.