Heat Pumps and Electric Heating - cfm too high on air handler- speed control?

Has anyone ever added a speed control? I'd like to slow it down. 208-253v Ever seen 1 in a catalog?
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The quandry is, the new "efficient" AH's all seem to be much higher cfm.
I'm about to order a new system and would like to get this right.

The LOW on the aruf374316 is 17 to 27% higher. this will be windy and not suck out much moisture due to the warmer coil temp. And it will be a cold wind on heat.

Ideas so far:
1. add speed control- will this make it hum?

2. put old blower into new unit with new motor, assuming cage is smaller.

3. get weenie AH with less efficiency(still 11% higher cfm)
3a. find VS blower that goes real slow, they are 3/4 HP vs. 1/2 hp on the 3 speed. Could not find minimum speed cfm listed so far.

4. try it as is and see if it works ok

or?

thanks lots!

The quandry is, the new "efficient" AH's all seem to be much higher cfm.

All should be about 400 cfm per ton! Nothing new about this!

The quandry is, the new "efficient" AH's all seem to be much higher cfm.

All should be about 400 cfm per ton! Nothing new about this!

RIGHT! i hope!
now, who sells them?

this 3Ton is 1925cfm H,
1550 M,
1345 L

should be 1200 cfm!

What you should have there is a V/S blower coil unit. then you can play with the blower speed with the dip switch in it. Also you can cut the speed down more with a humidistat at the unit or with some of the new tstat. But like said you should have about 400cfm per ton. A 3 ton blower coil Trane is 1060 CFM at a 0.1 external static pressurel ow and 1370CFM on high at the same 0.1 static. So you have to check and see what staic pressure your duct was layed out for .

Thanks Ed!
i'm going to check into the VS blower. with 50% more hp, 3/4 hp, i kind of expect even more flow, LOL
But, hopefully not. A humidistat in the unit sounds needed for my high RH.
I'm using 0.3 sp on the chart to compare, but i don't know what mine is.

1 dealer did say he sells a VS control to fit on 3 spd motors. I would just set it around ~1000 cfm and hopefully forget about it.

A side note,
I don't like real dry air as i tend to get colds. no colds in years! old system seems just right; no colds, no mold

my old ruud is 1/4 hp 11x7" cage, 1151 cfm set on H, at 0.3
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The proposed goodman VS is 3/4hp, 1020-2100 cfm.
Seems way too big, but maybe it could be set on 1020 permantly? costs $300 extra, i'm not pleased about that.
Really i think i'd need 700-900 cfm as a min to make use of a humidstat, just a wild guess at this point

the aruf363616 looks GREAT!
med 1140 vs 1151 on my old ruud
low 955 17% less if slow speed is needed to lower RH with the larger 13 seer coil(ruud was seer9) If i understand you guys right, too much air will not dehumidify with my double size system.

i'm not sure what high 1645 could be used for?

i have 2 277v 20a relays that i could wire for L M H if needed. Might be a nice toy, but

I plan to set it on LOW and see how it works.
If this is not a good plan i haven't ordered anything yet.
So please speak now.......i sure appreciate the helpful advice

i don't like the VS AH because the VS circuit is INSIDE the motor. HARD to service! NO WAY i'll buy a $300 option that cant easiy be bypassed in an emergency.

I think you are taking a penny wise, pound foolish attitude. The variable speed motors ARE quite expensive compared to a standard three or four speed motor but they will slow down to a crawl. You will not be able to find any aftermarket device that will give you this kind of control for any less money.

I can set my VS on "fan only" and get a gentle air movement that is barely audible. I tried using a cheap fan speed controller on my old furnace and the motor growled so bad I thought it needed some Tums.

Nor do I think that the fact that it can't be bypassed in an emergency holds much weight. Heck, the motor on your three-speed can burn out and leave you in the same fix. There are thousands of these VS motors in service, maybe even tens of thousands and I suspect the failure rate is no greater than the failure rate of the three or four speed motors.

I will state that these solid state motors and furnace control boards are much more susceptible to failure when being run on electricity supplied by inexpensive (read: poorly controlled voltage and frequency) generators so if you want to run your system during a power outage, take heed.

the VS MINIMUM is 1020 cfm (2100 max)
fixed is 955
i want the crawl speed .
fixed wins the speed race.
Thanks for mentioning the growl!
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also frequent lightning strikes make me wary of hard to get to pc. But if the speed slowed to 750 cfm i'd at least THINK about it. 1020 is a joke. if the controller was easy to get to i'd just swap it out, but why bother with it in the first place? too fast. poor value.

Ed
i'm going to ask the ac guy to check the static pressure.
Since my old ruud ran 19 yrs on 1 speed, 1151cfm,
hopefully 2 useful speeds 1140 and 955 will be enough to choose from.
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I emailed scott @ that r22 vs r410 link. Hopefully he will add info about the extra $$$$ r410 costs to run.
Thanks Ed!

If you are getting a new AH go with a VS blower. My 3 speed AH was only 4 years old so I didn't want to junk it just for VS. Instead I installed 4 - 24vac relays to automatically select speed based on function as follows:

AC = high speed
Fan, heat = Med speed
Humidfy, dehumidify = low speed

Works like a champ.

got the new goodman aruf363616 in! set on low(955-1040cfm). works great 1st test! nice and quiet.
very nice quality!
164# vs 98# on my old ruud.
Had to change flow piston from 74 to 73 supplied with condensor.

for those that want VS, i've learned the vs has a trimmer to cut min 15%, so it could go down to ~867 cfm. BUT it is not a true VS! just a few extra fixed speeds and NOTHING between 867 and 1020 cfm! Very glad i didn't get it.

Check out the Evergreen VS replacement motor. I think this is what you are looking for,