I have approximately a 4,000 sqft loft and not sure what size AC/
Furnace Unit I will need. Just trying to get a general idea. I was
looking at the following and not sure if it will be able to handle the
size of the room.
Goodman Air Conditioner/Furnace Package Unit
GOODMAN
Model: GPG13360901AB
13 SEER (cooling)
Cooling capacity: 35,400 BTU
80% AFUE (heating)
208 / 230 Volts
60 Hz
1 Phase
In other discussions like this, people have said the Goodman equipment is
"contractor grade", which is the same comment I got from the people who
inspected my home before purchase. The vague definition is "sorta kinda good
enough, but look at other brands".
As far as the size, a competent contractor will survey the space and make a
recommendation based on more factors than just square footage. Another
factor would be the number and sizes of windows, for instance. You should
consult a contractor.
Hi,
Why don't you get an extimate by a competent pro.
Up here, rule of thumb for cooling need is 1 ton(12,000BTU)
per 600 sqf. I am no expert but looks like you need bigger one.
My cousin is a roughneck and likes his home kept at 65 and he wants
it to reach that temp very quick, even in 110 degree weather.
The 'experts' measured the house and checked the insulation and then
told him that the manual whatever showed that he required a 2 ton
(24,000 btu) system.
He ended up with a free 5 ton (60,000 btu) system that has kept him
very happy. The 'expert' hvac guy was not very happy, though.
.
Thanks for all the replies. I did have one guy come by and his
estimate was nuts, so I was trying to get a rough idea before I called
more. I think I will need bigger than the one I listed almost double
from what I have calculated.
I see the truth comes out.
You can have it done cheap or you can pay to have it done right the first
time.
I guaranty that you won't like the cheap price after you've had many
problems with a system that sacrifices your comfort!
The truth comes out give me a break. The guy gave me a very rough no
calculations estimate of 25 grand, so yeah I'm going to ask questions.
So don't jump to conclusions.
That's great if you like that "cave clammy" feeling. It will be a cold
house that still has all the humidity since the oversized unit won't
run long enough to pull the humidity out. That may work fine in
Arizona but here in Florida it will make it "rain" in your house as
the humidity condenses on things..
I would have used a 3 ton if the "experts" said to use a 2 ton. Having lived
in Las Vegas for 15 years, I learned early on that too many "experts" and
contractors use the one ton per ~400 sq ft rule, and you end up with an a/c
unit too small to cool your house when the temp tops 115 (which is does for
weeks on end in July and August in Vegas). I replaced my 3 ton unit with a 4
ton unit, and I was in a/c heaven! However, Vegas is quite dry and quite
hot, so we don't need much dehumidifying action - we need extra cooling.
My office needs a 5000 btu a/c according to btu/sq foot charts. A 5000 btu
a/c runs and runs and runs during the peak of the day, it doesn't cool that
well. I now have a 6000 btu unit in the window sill The extra 20% is all it
takes to make the difference between sitting here sweating during the heat
of the day, and enjoying a nice cool office.
Anyone else care to comment on whether you go with the recommend size, or
upsize 20% or so? IANAE, and my limited experiences are certainly not
representative of a/c installs in general.
Why? A competent estimator performing a manual J calculation will give
the proper size to use.
Having lived
Unfortunately a BTU/square foot chart is only an extremely course guide
and isn't really accurate enough to properly select equipment.
it doesn't cool that
Because I've spent too many years living in houses with a/c units that were
sized according to the house size, and most of them ineadequate. When it hit
110+ outside, we sweltered inside because the a/c just couldn't handle the
load. I've had several of my units inspected by repairmen, and all of them
told me that the unit was working fine but just wasn't big enough for the
house. I had a 1200 sq ft house in Vegas, and a 3 ton a/c. It didn't cool
worth squat when the temp exceeded about 105. A contractor told me to
replace it with a 3 ton unit. I told him that the current 3 ton unit was
fine mechanically, but would not cool when it got too hot, and then he
suggested that because it's hotter in Vegas I might need a bigger unit.
Well, duh, why don't they do that in the first place? There is a big
difference between the size of the a/c unit need to cool a house in 90
degree humid weather, and 118 degree arid weather.
I wonder if the problem is that the contractors use the smallest unit they
can get away with, instead of one that will cool the house even when the
weather hits 118? IOW, a competent estimator would indeed give the right
size to use, but those that build houses like to cut costs when they can,
including using small a/c units?
Agreed. A couple of computers, other electrical equipment, a souther
exposure, etc. can make big differences in the size of the a/c you need.
"Ook" <Ook Don't send me any freakin' spam at zootal dot com delete the
Don't send me any freakin' spam> wrote
Wonder no more. Builders use as cheap as they can get away with.
The manual J is a very good method of determining the size AC you need, but,
it is dependent on proper input. If you design for a 20 degree differential,
but want a 30 degree differential, it is not going to work.
What works for me so far, is not to live in a place where the temperature
reaches 118 degrees.
"Ook" <Ook Don't send me any freakin' spam at zootal dot com delete the
Don't send me any freakin' spam> wrote in message
were
hit
That's the difference between a COMPETENT HVAC technician and a hack.
One knows that you sized the unit based on the "design temperature" for the
area in which it gets installed!
You just answered your own question. The calculations can't be correct
when the correct design conditions aren't used.
You get similar results in an area where heating is the predominant
issue. If the builder is trying to cheap out they use a higher outside
low temperature with the result being if there is a sustained cold snap
the inside design temperature cannot be reached.
There is a big
Sure, and manual J accounts for that. But if the right conditions aren't
used then the calculations are useless.
"Ook" <Ook Don't send me any freakin' spam at zootal dot com delete the
Don't send me any freakin' spam> wrote in message
Just another couple of pennies from a Las Vegan ......
I'm waiting as I type for a company to come install a compressor in one of
my vacation rentals. Seems like the morons renting it have been having
problems for a couple of weeks, "but the temperature was bearable." The
house has a five and a four ton unit. I can't say 100% sure that it
wouldn't have gone out anyway, so I can't charge them. Grrrrrrrrrrr.
Anyway, I always heard that ......... go with a bigger unit, and then it
doesn't have to work as hard. I know that this, too, has its logical
limitations, as you would not want to put a ten ton unit where you need
three. But I do consider putting an extra ton on there to be a reasonable
thing to do.
We're replacing this compressor with another five, as the house has nine
tons for 2800 sf. And yes, the units don't run that much of the time and it
doesn't take long to cool it down. Plus, for a few months a year, two swamp
coolers blow plenty of cool air.
Things people can do, but don't, include adding shades and awnings,
installing window tint, stopping up holes, having someone go into the attic
and retape all the places that have come loose or weren't taped in the first
place, closing the doors when you go outside, having the unit serviced once
a year, clearing leaves and crud from around air conditioner, not setting
the unit at 47 degrees and leaving for ten hours so it will be cool when you
return, and about eighteen other logical things that many people consider to
be incomprehensible.
Supposed to be 116 here today. Wonder if it will make it.
Steve
Ahhh, Las Vegas, home sweet home. 116 this early in July? Niiicceee. I have
fond memories of painting the eaves of my house in early August when it was
118 outside. I had no choice, as the house was selling and I had to get it
done. I thought I was going to die up on that roof....
"Ook" <Ook Don't send me any freakin' spam at zootal dot com delete the
Don't send me any freakin' spam> wrote in message
On the good side, the paint dries so fast when you're painting the eaves, if
you drip some, it just bounces off the concrete.
We're 98% moved to Utah, and are just waiting for the houses here to sell.
I also have lots of fond memories of Las Vegas. Lately, it's just turned
into a crowded cesspool.
I liked it better when "The Boys" ran things.
Steve
I moved there in 1984, and left at the end of the year 2000. When I moved
there, there was no Green Valley, and US95 dead ended at the spaghetti bowl.
Lake Mead Drive (not to be confused with Lake Mead Blvd in NLV) went from
the old part of Henderson all the way to I-15 with only one traffic light,
and there was a couple of miles of empty desert along Boulder Highway
between Vegas and Henderson. There was also an empty mile or two of Las
Vegas Blvd at Nellis AFB. You could actually drive across the dam, and the
tours took you down the looong elevator to the bottom platform. When I left,
the road to Lake Mead had a toll station, the city was complete from Vegas
all they way along Boulder Highway to Henderson, and Green Valley stretched
from I-15 to Water Street, civilization stretched all the way to the air
base and beyond, traffic was insane, and it was beginning to get very
crowded. Real Estate had not yet exploded upwards, and I sold my house for
$99,500. Today that house is worth about $250,000. I walked away $150,000 -
all I had to do was stay there for five more years <cries>.
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