Looking for a good A/C installer (Manual J) - Denver Metro
 

I am looking for an A/C installer that uses the Manual J method to
correctly size the new unit. Someone who is thorough, will use correct
inputs, and won't cut corners on the formulas.

In Denver Metro, Colorado

TIA

Looking for a good A/C installer (Manual J) - Denver Metro
 

wrote in message
ups.com...
I am looking for an A/C installer that uses the Manual J method to
correctly size the new unit. Someone who is thorough, will use correct
inputs, and won't cut corners on the formulas.

In Denver Metro, Colorado

Give Alex a call, tell him I sent you.

Alex Walter
Furnaces, A/C & More
12255 E Harvard Dr
Aurora CO 80014-1919
USA

Voice: 303-695-1465
Fax: 303-695-4543
email:

Looking for a good A/C installer (Manual J) - Denver Metro
 

On Mon, 11 Jun 2007 08:20:55 -0700, someone wrote:

...Someone who is thorough, will use correct
inputs, and won't cut corners on the formulas.

To what end is the need to be that precise? They will just size it to
the nearest ton (or maybe half ton) anyway. It's not like it's going
to make much difference if it comes out 38,052 btu/hr for the anal
retentive guy, or 41,019 btu/hr for the good enough for government
work guy.


Reply to NG only - this e.mail address goes to a kill file.

Looking for a good A/C installer (Manual J) - Denver Metro
 

"v" wrote in message
...
On Mon, 11 Jun 2007 08:20:55 -0700, someone wrote:

...Someone who is thorough, will use correct
inputs, and won't cut corners on the formulas.

To what end is the need to be that precise? They will just size it to
the nearest ton (or maybe half ton) anyway. It's not like it's going
to make much difference if it comes out 38,052 btu/hr for the anal
retentive guy, or 41,019 btu/hr for the good enough for government
work guy.


Reply to NG only - this e.mail address goes to a kill file.


Might as well guess on everything, Eh?

Looking for a good A/C installer (Manual J) - Denver Metro
 

On Jun 12, 4:07 pm, (v) wrote:
On Mon, 11 Jun 2007 08:20:55 -0700, someone wrote:
...Someone who is thorough, will use correct
inputs, and won't cut corners on the formulas.

To what end is the need to be that precise? They will just size it to
the nearest ton (or maybe half ton) anyway. It's not like it's going
to make much difference if it comes out 38,052 btu/hr for the anal
retentive guy, or 41,019 btu/hr for the good enough for government
work guy.

And what if it's more like borderline - "back of napkin" calc will
suggest 2-ton, but Manual J suggests 1.5-ton.

Looking for a good A/C installer (Manual J) - Denver Metro
 

Looking for a good A/C installer (Manual J) - Denver Metro
 

wrote in message
oups.com...
On Jun 12, 4:07 pm, (v) wrote:
On Mon, 11 Jun 2007 08:20:55 -0700, someone wrote:
...Someone who is thorough, will use correct
inputs, and won't cut corners on the formulas.

To what end is the need to be that precise? They will just size it to
the nearest ton (or maybe half ton) anyway. It's not like it's going
to make much difference if it comes out 38,052 btu/hr for the anal
retentive guy, or 41,019 btu/hr for the good enough for government
work guy.

And what if it's more like borderline - "back of napkin" calc will
suggest 2-ton, but Manual J suggests 1.5-ton.

The customer gets a complete print-out of the Manual J and Manual D
calculations that tell exactly what is required. Unless you do the math and
run the calculations, your doing nothing but guessing.
Do *you* want to base that kind of investment and cash outlay on a guess??

Looking for a good A/C installer (Manual J) - Denver Metro
 

wrote in message
oups.com...
On Jun 12, 4:07 pm, (v) wrote:
On Mon, 11 Jun 2007 08:20:55 -0700, someone wrote:
...Someone who is thorough, will use correct
inputs, and won't cut corners on the formulas.

To what end is the need to be that precise? They will just size it to
the nearest ton (or maybe half ton) anyway. It's not like it's going
to make much difference if it comes out 38,052 btu/hr for the anal
retentive guy, or 41,019 btu/hr for the good enough for government
work guy.

And what if it's more like borderline - "back of napkin" calc will
suggest 2-ton, but Manual J suggests 1.5-ton.


v would probably suggest a 3-ton unit in that example. rolleyes

Looking for a good A/C installer (Manual J) - Denver Metro
 

On Tue, 12 Jun 2007 20:11:54 -0500, someone wrote:


The customer gets a complete print-out of the Manual J and Manual D
calculations that tell exactly what is required. Unless you do the math and
run the calculations, your doing nothing but guessing.
Do *you* want to base that kind of investment and cash outlay on a guess??

What I'm getting at is, how does one "cut corners on the formulas"
when the contractor is using a commercial spreadsheet package where he
puts in the parameters and the "formulas" are built in. I used to do
these calcs "by hand". I doubt most contractors could, they just use
their computer package and the answer is whatever it says. So what
that they give a copy of the printout to the homeowner. Don't confuse
accuracy with precision.

If a window is 4'-8" by 3'-4" but the contractor figured it as 3 x 5
feet, is it going to matter that he took a shortcut with the formula?

So you get an "exact" calc, but the units are not made in that "exact"
size. Then you ask the contractor to use his experience, judgment and
understanding of principles to tell you that you are better off with
the one that is a little undersized even though the one that is a very
little bit oversized is closer to the "exact" figure.

I'm not impressed with people who toss around an "exact" figure that
just came out of a computer as if that means the person holding it
knows something.



Reply to NG only - this e.mail address goes to a kill file.

Looking for a good A/C installer (Manual J) - Denver Metro
 

On Tue, 12 Jun 2007 21:01:56 -0500, someone wrote:


v would probably suggest a 3-ton unit in that example. rolleyes

The contractor can't "cut corners on the formula" because he likely
doesn't have and doesn't know the formula anyway. He just punches the
numbers in to something that he bought and then tries to impress you
with the resultant printout.

I used to do these "by hand" (okay, pocket calculator) back in the
day. Don't confuse precision with accuracy. Garbage in garbage out.
You are better off with someone who can make a reasoned estimate here
and there, than with someone who laboriously inputs precise fractions
but uses the wrong conditions and assumptions because he is just doing
data entry and not understanding principles.





Reply to NG only - this e.mail address goes to a kill file.

Looking for a good A/C installer (Manual J) - Denver Metro
 

"v" wrote in message
...
On Tue, 12 Jun 2007 21:01:56 -0500, someone wrote:


v would probably suggest a 3-ton unit in that example. rolleyes

The contractor can't "cut corners on the formula" because he likely
doesn't have and doesn't know the formula anyway. He just punches the
numbers in to something that he bought and then tries to impress you
with the resultant printout.

I used to do these "by hand" (okay, pocket calculator) back in the
day. Don't confuse precision with accuracy. Garbage in garbage out.
You are better off with someone who can make a reasoned estimate here
and there, than with someone who laboriously inputs precise fractions
but uses the wrong conditions and assumptions because he is just doing
data entry and not understanding principles.


Yeah, well, we don't send out a rookie with a computer to perform a load
calc.

If you'd send someone out that has HVAC knowledge, you would understand that
a load calc *is* worthwhile.

Might as well install that 5-ton unit, Eh?

Looking for a good A/C installer (Manual J) - Denver Metro
 

"v" wrote in message
...
On Tue, 12 Jun 2007 20:11:54 -0500, someone wrote:


The customer gets a complete print-out of the Manual J and Manual D
calculations that tell exactly what is required. Unless you do the math
and
run the calculations, your doing nothing but guessing.
Do *you* want to base that kind of investment and cash outlay on a guess??

What I'm getting at is, how does one "cut corners on the formulas"
when the contractor is using a commercial spreadsheet package where he
puts in the parameters and the "formulas" are built in. I used to do
these calcs "by hand". I doubt most contractors could, they just use
their computer package and the answer is whatever it says. So what
that they give a copy of the printout to the homeowner. Don't confuse
accuracy with precision.

I used to be able to manually do load calcs, but that was before I had a
computer and the software to do it with more precission, and a bit faster
too.
Without precission, you don't have accuracy.

If a window is 4'-8" by 3'-4" but the contractor figured it as 3 x 5
feet, is it going to matter that he took a shortcut with the formula?

In the grand scheme of things, probably not, or not enough to make a
difference. FWIW, I *DO* use the exact measurements.

So you get an "exact" calc, but the units are not made in that "exact"
size. Then you ask the contractor to use his experience, judgment and
understanding of principles to tell you that you are better off with
the one that is a little undersized even though the one that is a very
little bit oversized is closer to the "exact" figure.

The load calc will tell you what btu capacity you need, and the
manufacturers specs will tell you whats available. Somewhere you have to
come to a happy medium.

I'm not impressed with people who toss around an "exact" figure that
just came out of a computer as if that means the person holding it
knows something.

Nobody asked if you were impressed or not....I just do the very best I know
how to do. so why are you here trying to stir the pot??

Looking for a good A/C installer (Manual J) - Denver Metro
 

On Wed, 13 Jun 2007 16:03:36 -0500, kjpro @ usenet.com wrote:


"v" wrote in message
...
On Tue, 12 Jun 2007 21:01:56 -0500, someone wrote:


v would probably suggest a 3-ton unit in that example. rolleyes

The contractor can't "cut corners on the formula" because he likely
doesn't have and doesn't know the formula anyway. He just punches the
numbers in to something that he bought and then tries to impress you
with the resultant printout.

I used to do these "by hand" (okay, pocket calculator) back in the
day. Don't confuse precision with accuracy. Garbage in garbage out.
You are better off with someone who can make a reasoned estimate here
and there, than with someone who laboriously inputs precise fractions
but uses the wrong conditions and assumptions because he is just doing
data entry and not understanding principles.


Yeah, well, we don't send out a rookie with a computer to perform a load
calc.

If you'd send someone out that has HVAC knowledge, you would understand that
a load calc *is* worthwhile.

Might as well install that 5-ton unit, Eh?


Where I come from, rule of thumb for average constructed homes is 1
ton/500 sq ft (8ft ceiling). Of course it's not calculated but I bet
it's close to accurate for the average home where I am.

Looking for a good A/C installer (Manual J) - Denver Metro
 

RT wrote in message ...
On Wed, 13 Jun 2007 16:03:36 -0500, kjpro @ usenet.com wrote:


"v" wrote in message
...
On Tue, 12 Jun 2007 21:01:56 -0500, someone wrote:


v would probably suggest a 3-ton unit in that example. rolleyes

The contractor can't "cut corners on the formula" because he likely
doesn't have and doesn't know the formula anyway. He just punches the
numbers in to something that he bought and then tries to impress you
with the resultant printout.

I used to do these "by hand" (okay, pocket calculator) back in the
day. Don't confuse precision with accuracy. Garbage in garbage out.
You are better off with someone who can make a reasoned estimate here
and there, than with someone who laboriously inputs precise fractions
but uses the wrong conditions and assumptions because he is just doing
data entry and not understanding principles.


Yeah, well, we don't send out a rookie with a computer to perform a load
calc.

If you'd send someone out that has HVAC knowledge, you would understand
that
a load calc *is* worthwhile.

Might as well install that 5-ton unit, Eh?


Where I come from, rule of thumb for average constructed homes is 1
ton/500 sq ft (8ft ceiling). Of course it's not calculated but I bet
it's close to accurate for the average home where I am.

Gee..... where I am at, there is no rule of thumb.... I have homes with
*correctly sized*(calculated) systems that range anywhere from 500sqft per
ton up to 1500sqft per ton, with an average being 700sqft/ton with design
temps of 98DB/77WB for cooling and 28DB for heating.

Looking for a good A/C installer (Manual J) - Denver Metro
 

RT wrote in message ...
On Wed, 13 Jun 2007 16:03:36 -0500, kjpro @ usenet.com wrote:


"v" wrote in message
...
On Tue, 12 Jun 2007 21:01:56 -0500, someone wrote:


v would probably suggest a 3-ton unit in that example. rolleyes

The contractor can't "cut corners on the formula" because he likely
doesn't have and doesn't know the formula anyway. He just punches the
numbers in to something that he bought and then tries to impress you
with the resultant printout.

I used to do these "by hand" (okay, pocket calculator) back in the
day. Don't confuse precision with accuracy. Garbage in garbage out.
You are better off with someone who can make a reasoned estimate here
and there, than with someone who laboriously inputs precise fractions
but uses the wrong conditions and assumptions because he is just doing
data entry and not understanding principles.


Yeah, well, we don't send out a rookie with a computer to perform a load
calc.

If you'd send someone out that has HVAC knowledge, you would understand
that
a load calc *is* worthwhile.

Might as well install that 5-ton unit, Eh?


Where I come from, rule of thumb for average constructed homes is 1
ton/500 sq ft (8ft ceiling). Of course it's not calculated but I bet
it's close to accurate for the average home where I am.


Where I come from, I do things correctly. That means the client gets a
Manual J to correctly size his or her new system. However, there are hacks
everywhere that use "rules of thumb" for just about everything. Their
clients are unhappy when they receive a quote to fix all the screw-ups.

Do it right, or do it twice. I garranty doing it right the first time is
cheaper in the long run!

Looking for a good A/C installer (Manual J) - Denver Metro
 

On Sun, 17 Jun 2007 17:00:10 -0500, RT wrote:

Where I come from, rule of thumb for average constructed homes is 1
ton/500 sq ft (8ft ceiling). Of course it's not calculated but I bet
it's close to accurate for the average home where I am.

Wow, that would make for a huge appliance, sounds oversized by quite a
bit. I have a 3 ton York AC for my 2,450 sf house, and it's pretty
good, except that the attic is noticeably warmer than the rest of the
house. Anything larger would be a waste as we don't have proper cold
air returns everywhere we should on the upper floors (built in 1930,
long before central air).