Yo Jeanius

[The King]

Lets plug your numbers into this and tell me what you get.

CFM = volts x amps x 3.412 / 1.08 x temperature rise

= 237 x 20 x3.412 / 1.08x 19

=16177 / 20.5

788 CFM

You need 400 CFM per ton so Id say your as good as it gets air flow wise. 12 CFM isn't going to mean jack shit in over all performance. You are more than welcome to look it up on a fan performance curve.

Air flow isn't causing your HP to be noisey while switching into and being in defrost.

Moving along..

3.412 BTUH = 1 watt.

To find BTUH using the temp rise across a electric heat element the formula is the Sensible Heat Equation.

BTUH = E x I x 3.412

Now that you know the BTUH you can find CFM by using the formula at top

To find BTUH in heat mode;

BTUH = CFM x TD (db) x 1.08

To find BTUH in cooling mode;

BTUH = CFM x HD x 4.5

HD = total heat difference ie. Enthalpy DT measured in wet bulb across the HX. You'll need a total heat chart to get those numbers unless you post accurate wet bulb numbers in cooling I cant help.

4.5 is a constant, once again at sea level which changes with altitude. A mute point in your case.

Now throw those shit equations in the trash and get to work.

Otherwise I will enjoy my morning bowl of Coco Puffs for breckfy and thank God you helped to make it possible. :)

Hope this helps.

[Jean]

Is your formula ordered as follows?

A) 237 x 20 x 3.412 / 19 x 1.08 = 919 which is the same as 237 x 20 x 3.412 x 1.08 / 19 = 919

or is it

B) 237 x 20 x 3.412 / (19 x 1.08) = 788

Remember your math rules from school?

Rule 1: First perform any calculations inside parentheses. Rule 2: Next perform all multiplications and divisions, working from left to right. Rule 3: Lastly, perform all additions and subtractions, working from left to right.

If your formula is right, then Goodman's printed installation & operating sheets are good for shit. (Their heating performance data sheet for my product is crap. It shows R22 data but labelled for R410. My HVAC guy says to throw them out. They are worthless.)

I know. I've had to "prove" my airflow. People keep pointing at other reasons for their problems. I have no choice. Goodman insists on knowing actual airflow. They have been picky about charge TO THE OUNCE.

CFM = BTUH / (TD x 1.08)

If this is correct, then Goodman's formula is shit. See my post in the other thread. I've given URL's to their data sheets.

Do you have a URL for your formula?

You REALLY don't want to know what actually goes into making Coco Puffs ;)

Yep.

[The King]

Neither. It's (237 x 20 x 3.412 ) / (19 x 1.08) = 788

Please don't lecture me on math rules. Thank you.

[Jean]

Which is identical to B)

Can you give me a URL that has your formula? I'll need it to back up your calculations. "Some guy on a newsgroup" won't hold much sway.

I do appreciate your help. And I realize this air flow business is not really consequential to solving my problem.

[The King]

Exactly.

Ahem.. some guy?? I'm the God damn KING here! You tell them I said so.

Try Googling Sensible Heat Equation and Total Heat Equation or some variable of such. I'm sure its out there somewhere. Check the Engineering Toolbox they may have something.

The problem is Goodman is just shit equipment. Its always been loud. That's why they say its normal. Wanna fix it. Junk it and get something better. I know you don't want to hear that and they will never say it but that's the facts Jack.

It's either that or engineer a Cone of Silence for it in your spare time. :)

[Jean]

Here's what I said in an earlier post:

"I'm beginning to think the only solution to the noisy machine is to sell tickets to a "heat pump bash". $100 for the first swing with a baseball bat at the thing $95 for the second $90 for the third etc etc The person who puts it completely out of it's misery will get their ticket money back.

Afterwords we'll take it out to the country and roast it on a huge bonfire."

I'll get out my cement calculator. Should it be 4 inches thick or do you think 6 would be better?

It's been a slice... I'm gonna toddle off now.

Have a good one.

[Jean]

I will ;)

After a quick google:

Q = 1.08 x cfm x deltaT Where: Q = Load in Btu/hr. 1.08 = Another one of those pesky units conversion constants that are dependent on the conditions of the fluid associated with the equation (in this case, air, and the constant is good for typical HVAC systems at or near sea level) cfm = System flow rate in cubic feet per minute deltaT = Temperature rise or drop in °F

Therefore: TR = BTUH / (CFM x 1.08)

which is NOT Goodman's TR = kW x 3412 x 1.08 / CFM

The King = 1 Goodman = -3

Thanks for input. I'm going to run another duct tomorrow and squeeze out a little more heat before the pump blows up.

[The King]

It's a good thing I don't get headaches... :)

Good luck dude.