Home Page link

ac size

HVAC Discussions - Heating, ventilation and air conditioning. 

Page 1 of 6       1 2 3 > last >> Bookmark this page:  YahooMyWeb Yahoo!  Google Google  Windows Live Favorites Windows Live  del.icio.us del.icio.us  digg digg  Add to Netscape Netscape
Subject Author Date
ac size Jon Clark 06-07-2007
---> Re: ac size HVAC fella06-14-2007
`--> Re: ac size geothermaljones06-14-2007
If you were  Registered and logged in, you could reply and use other advanced thread options
Posted by Jon Clark on June 7, 2007, 12:05 am
Greetings,
I am badly in need of opinions. Although I have seen this issue discussed in
several threads, I still am uncertain as to which direction to head.
I recently replaced our AC. At the time of the quoting process, my house was
calced at 31/2 ton (1800sf, ss, 100+ summers). Upon selecting the
contractor, I asked for the 16 seer. I was told it only came in 4 ton, but
since it was 2 stage, it would not be oversized for my house. I went with
it. 2 weeks after install, I was on the manufactures web site and saw that
the unit was not 2 stage. I presented this to the rep and he got back to me
admitting he had made a mistake and that brand did not have a 4 ton 2 stage.
Although, he claims they will make it right, he feels that the 4 ton single
stage will be OK for our house/area (of course). So far we have not had
enough hot weather to heavily test the unit. We have had a few warm days
where we ran it for a few hours. I did notice it being slightly humid, as
far as what constitutes a short run cycle, I am uncertain. It didn't seem to
start/stop excessively.
So, should I press for a change out now, wait for hotter weather before
deciding, or is the difference between 3.5-4 ton so marginal that there is
likely no problem? Thanks in advance for any advice.
Posted by udarrell on June 7, 2007, 11:26 am
Jon Clark wrote:
show/hide quoted text
Concerning the condenser, it is unthinkable that he could have made such
an error in claiming he was installing a two stage unit!
I need to know what major city you live near to get the Summer Design
Conditions there!
Here in SW WI with Heat Indexes up to 104, there are 2400-sq.ft. homes
with 2-ton units cooling them perfectly.
You need a manual J (heatload sizing) done, also manual D (duct sizing),
& then a manual S (unit Sizing) done, even then both tend to oversize to
some degree.
http://www.udarrell.com/proper_cfm_btuh_duct_sizing_air_conditioning_systems.html
At the top Click On: Basic AC Overview - "Specifications vs. Reality" -
udarrell
--
WISDOM PRINCIPLE DIRECTED EMPOWERMENT COMMUNICATIONS -
THE REAL POLITICAL ISSUES and WISDOM BASED PEOPLE EMPOWERMENT
http://www.udarrell.com/
http://www.udarrell.com/my_pages2.htm
http://www.udarrell.com/recognizing_real_enemies.html ***
http://jesuschristsavior.net/Beatitudes.html
Reality Is Not An Easy Thing To Be Confronted With, or to Accept!
Posted by Jon Clark on June 7, 2007, 8:52 pm
show/hide quoted text
http://www.udarrell.com/proper_cfm_btuh_duct_sizing_air_conditioning_systems.html
show/hide quoted text
Thanks for the response. I live near Sacramento CA though we are typically
3-5 degrees warmer. I had 3 different calcs down showing 3.5 ton, but of
course that doesn't mean any of them were correct. I am leaning towards
having them put a 3.5 ton in, but I was hoping that someone would show
reason as to why it would be pointless. Do you know if he was full of crap
in his opinion that a 2 stage 4 ton would indeed be a good fit? He basically
explianed that most of the time the AC would be running at a 2 ton level
except for the middle of the summer where the 4 ton would be needed. Thanks.
Posted by udarrell on June 7, 2007, 11:37 pm
Jon Clark wrote:
show/hide quoted text
udarrell
show/hide quoted text
Sacramento, CA Summer Design 98-F dry bulb 70-F wet bulb around only
25% Relative Humidity.
Even if it is 3-5 degrees hotter with that low a humidity the system
should bring the sensible temp down with ease unless you have extreme
heatload conditions.
We cannot do a manual J from here, however the experts claim the manual
J and S tend to oversize the systems.
I know nothing about your system ductwork, airflow, etc. Therefore, I'm
simply whistling dixie.
I use a mere half ton 6,000-BTUH room AC that cools perfectly the first
floor 3 rooms & a hallway, over 900-sq.ft. at 104 Heat Indexes!
900 / .5 ton = 1800 Sq.Ft per a ton of cooling in an old 1930's home,
come here on our hottest days and I will prove it to you! (Airflow!)
show/hide quoted text
(It's True.)
Below is an outstanding PDF "Basic AC Overview - Specifications vs Reality"
by John Proctor, P.E., Proctor Engineering Group, LTD:
HVAC TECH PERFORMANCE RATINGS
show/hide quoted text
PDF - Few are done Right!
DISCLAIMER:
I assume NO responsibility for the USE of any information I post on any
of my Web pages or in any NGs.
All HVAC/R work should always be done by a licensed Contractor &
properly licensed Techs! This information is only placed on these pages
for your understanding & communication with contractors & techs. This
information is also for the edification of Contractors and Techs. I am
NOT liable for anyone's screw-ups! - udarrell
--
WISDOM PRINCIPLE DIRECTED EMPOWERMENT COMMUNICATIONS -
THE REAL POLITICAL ISSUES and WISDOM BASED PEOPLE EMPOWERMENT
http://www.udarrell.com/
http://www.udarrell.com/my_pages2.htm
http://www.udarrell.com/recognizing_real_enemies.html ***
http://jesuschristsavior.net/Beatitudes.html
http://www.antiwar.com/ ***
Reality Is Not An Easy Thing To Be Confronted With, or to Accept!
Posted by udarrell on June 8, 2007, 8:55 am
Jon Clark wrote:
show/hide quoted text
udarrell
show/hide quoted text
Sacramento, CA Summer Design 98-F dry bulb 70-F wet bulb around only
25% Relative Humidity, 75-F indoors at 50%-RH.
Even if it is 3-5 degrees hotter with that low a humidity the system
should bring the sensible temp down with ease unless you have extreme
heatload conditions.
We cannot do a manual J from here, however the experts claim the manual
J and S tend to oversize the systems.
I know nothing about your system ductwork, airflow, etc. Therefore, I'm
simply whistling dixie.
I use a mere half ton 6,000-BTUH room AC that cools perfectly the first
floor 3 rooms & a hallway, 900-sq.ft. at 104 Heat Indexes! Even if we
reduced it to 800-sq.ft. it would be 800 / .5 = 1600-sq.ft per ton of
cooling. At 900-sq.ft. / .5 ton = 1800 Sq.Ft per a ton of cooling in an
old 1930's home. It says "cools rooms up to 225-sq.ft., not with my
techniques; it cools over 7 times that area with NO other AC running
anywhere in my home.
Come here on our hottest days and I will prove it to you! My brother
knows it is true, but we both can't believe it, it is unreal.
(Air Circulation & putting an optimal heatload on the evaporator coil!)
show/hide quoted text
(It's True.)
Below is an outstanding PDF "Basic AC Overview - Specifications vs Reality"
by John Proctor, P.E., Proctor Engineering Group, LTD:
HVAC TECH PERFORMANCE RATINGS
show/hide quoted text
PDF - Few are done Right!
A majority of ACs are oversized. When a system does not cool
sufficiently it is 'usually' due to other factors other than unit sizing!
DISCLAIMER:
I assume NO responsibility for the USE of any information I post on any
of my Web pages or in any NGs.
All HVAC/R work should always be done by a licensed Contractor &
properly licensed Techs! This information is only placed on these pages
for your understanding & communication with contractors & techs. This
information is also for the edification of Contractors and Techs. I am
NOT liable for anyone's screw-ups! - udarrell
--
WISDOM PRINCIPLE DIRECTED EMPOWERMENT COMMUNICATIONS -
THE REAL POLITICAL ISSUES and WISDOM BASED PEOPLE EMPOWERMENT
http://www.udarrell.com/
http://www.udarrell.com/my_pages2.htm
http://www.udarrell.com/recognizing_real_enemies.html ***
http://jesuschristsavior.net/Beatitudes.html
http://www.antiwar.com/ ***
Reality Is Not An Easy Thing To Be Confronted With, or to Accept!
Page 1 of 6       1 2 3 > last >>
Similar ThreadsPosted
Grille Size vs Duct Size October 29, 2007, 9:55 am
What size AC do i need? August 7, 2006, 6:21 pm
Size of A/C Unit July 1, 2006, 3:22 pm
compressor size? August 7, 2006, 11:30 am
Gas pipe size February 21, 2008, 5:18 pm
calculating capillary size February 14, 2007, 5:19 am
how contractors really size aircon October 5, 2007, 1:00 pm
Re: What size is my Comfortmaker A/C unit? April 12, 2006, 3:09 pm
Re: What size is my Comfortmaker A/C unit? April 12, 2006, 8:04 pm
Re: What size is my Comfortmaker A/C unit? April 13, 2006, 9:01 pm

Contact Us | Privacy Policy

XML SitemapXML Sitemap