Home Page link

Is Measuring Superheat at Compressor of Any Value?

Home| Search | About
Login Password
Register Now! Lost Password?

HVAC Discussions - Heating, ventilation and air conditioning. 

Page 4 of 5       < 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
Is Measuring Superheat at Compressor of Any Value? Ken Hall 07-24-2006
If you were  Registered and logged in, you could reply and use other advanced thread options
Posted by Ken Hall on July 25, 2006, 9:39 am
On Tue, 25 Jul 2006 02:13:24 GMT, "Stormin Mormon"

>Not a lot of difference in a 30 foot lineset, if the suction line is
>well insulated.

Thanks for your reply.

>How many tons?

3.5

>Which refrigerant?

R22

>Orifice, or TXV coil?

capillary tubes/orifice

>Liquid line temp and pressure at condensing unit?

Temp of line out of compressor (between compressor and condenser) 102F
Can't measure pressure because fitting is damaged/deformed

>Suction line temp and pressure?

Temp is about 45F
Pressure 61

>Good air flow through evaporator?

Yes

>Good air flow through conensor?

Yes

>Ourdoor temp?

79F

>Temp of hot air top of condensor fan?

91F

>Return air temp indoors?

55F

>High humidity indoors?

45%

>Supply air temp indoors?

73F


-- Ken

PexSupply Full Banner
Posted by Stormin Mormon on July 25, 2006, 5:10 pm
>How many tons?

3.5

>Which refrigerant?

R22
CY: Sounds like a typical residential system.

>Orifice, or TXV coil?

capillary tubes/orifice

>Liquid line temp and pressure at condensing unit?

Temp of line out of compressor (between compressor and condenser) 102F
Can't measure pressure because fitting is damaged/deformed
CY: 102 isn't that bad. I'd neglected to ask / mention. The liquid
line oughta be close to the outdoor air temp. If it's much hotter than
the outdoor air, it indicates dirty condensor.

>Suction line temp and pressure?

Temp is about 45F
Pressure 61
CY: Hmm. About ten degrees superheat. Should be more like 15 degrees.
That suggests the overcharge you were wondering about.

>Good air flow through evaporator?

Yes

>Good air flow through conensor?

Yes

>Ourdoor temp?

79F

>Temp of hot air top of condensor fan?

91F

>Return air temp indoors?

55F
CY: Wow, your house is 55F?

>High humidity indoors?

45%

>Supply air temp indoors?

73F
CY: And the furnace is on? Pumping hot air into the house?

-- Ken

CY: Well, seeing as how it's making 18F difference in indoor air,
something is right. But the sweat back does indicate overcharge.



Posted by Ken Hall on July 26, 2006, 1:45 pm
On Tue, 25 Jul 2006 21:10:37 GMT, "Stormin Mormon"

>55F
>CY: Wow, your house is 55F?

Yes, I got supply and return reversed in my head,

Thank you for your help.

-- Ken

Posted by Stormin Mormon on July 24, 2006, 10:08 pm
At the condensing unit is where I typically measure superheat. Tuck my
temp probe into the end of the black foam wrap.

Also check the amperage draw of the condensing unit. But, for the
moment it sure sounds like overcharge and flooding evaporator. Do you
have good air flow through the evaporator? And what kind of temps and
pressures are you showing?

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
.


The suction line sweats heavily at the compressor and the liquid line
leaving the compressor is barely warm. This suggests to me the system
is overcharged. It's easy for me to measure the superheat at the
compressor (split unit), but not at the evaporator. Will a reading at
the compressor tell me anything useful about the system charge?

Another way of asking this is how much is a typical difference in the
evaporator superheat and the condenser superheat in a split unit? The
suction line is about 30 feet long.

-- Ken



Posted by on July 24, 2006, 10:11 pm

>
>The suction line sweats heavily at the compressor and the liquid line
>leaving the compressor is barely warm. This suggests to me the system
>is overcharged. It's easy for me to measure the superheat at the
>compressor (split unit), but not at the evaporator. Will a reading at
>the compressor tell me anything useful about the system charge?
>
>Another way of asking this is how much is a typical difference in the
>evaporator superheat and the condenser superheat in a split unit? The
>suction line is about 30 feet long.
>
>-- Ken

In order to effectively troubleshoot your system over the internet we
will need from you the following:

air inlet & outlet temps at the evap
suction line pressure
suction line temp near the evap
suction line temp near the compressor

air inlet & outlet temps at the condenser
liquid line pressure
liquid line temp near the condenser outlet
liquid line temp near the metering device

make & model number of equipment and type of refrigerant.

suggest you learn a tad bit more before you start diagnosing things
you know jack-shit about.

Page 4 of 5       < 1 2 3 > last >>
Similar ThreadsPosted
Automotive Superheat ? August 3, 2006, 1:32 pm
how to base superheat August 25, 2007, 2:07 pm
Updated replacement Compressor Model Number for a 21 year old dead compressor(s) September 12, 2007, 12:34 am
Should AC compressor hum June 8, 2007, 11:06 am
Look Ma... No Compressor August 11, 2008, 5:55 am
Odd Terminals on AC Compressor July 18, 2006, 12:15 am
compressor size? August 7, 2006, 11:30 am
AC compressor shuts off after 20 min April 23, 2007, 3:52 pm
Compressor delay July 22, 2007, 8:29 pm
new coil or new compressor or both? June 20, 2008, 12:20 pm

Contact Us | Privacy Policy

XML SitemapXML Sitemap