|
My ordered procedure that must be followed
to achieve an optimally charged
efficient operating air conditioner.
Do not leave out any of the
steps and always do these procedures in the
order sequence illustrated.
*Important; Go to my
blog
for the required data to get on paper for effective trouble shooting:
http://udarrell.com/udarrell_hvac_blog/
First,
Check to see that there are NO air leaks in the Supply and Return Air
duct system.
Next, Check to see if Indoor Squirrel Cage
Blower wheel blades
are free of lint or other build-up & Filter.
Check for a dirty lint
clogged Evaporator Coil fins then check the Condenser Coil fins, check
both coils on the air entering sides as well as between the fins, -- clean if needed.
Take a
look at the ductwork for proper sizing and for leaks, Check
the External Static Pressure (ESP), check the indoor Cubic Feet per Minute
(CFM) Airflow, then outdoor
condenser discharge air
Temperature split (delta-T), then indoor
Delta-T, then after
15 minutes of run time before any charging
adjustments are made. On smaller tonnage equipment & in most
climates that are not overly humid, I like 425 to 450-CFM per/ton of
cooling
on a wet coil.
Formula
for finding CFM Airflow
If you can
measure the air velocity coming from a duct, here is a rough
ballpark formula to get the CFM:
CFM
=
(velocity in (FPM) Feet per Minute times the square footage
of the duct area)
Example, 16" Rd duct
201-sq.ins. X's 0.00694 = 1.39494-sq.ft. X's Velocity
of
800-fpm = 1,116-CFM
Times 1000-FPM = 1395-CFM.
Branch ducts: 7" Rd duct 38.48-sq. ins. X's
0.00694 =
0.2670512-sq.ft. X's 500-fpm=133.5-cfm
However, times a velocity of 600-FPM X's 0.00694 = 160-CFM, the velocity is a big room CFM &
BTUH number changer.
WARNING:
on units with a Thermostatic Expansion Valve (TXV), you cannot use the
suction pressure to check the charge; many appear to be doing this; it
tells you nothing.
Only after you have verified that all the coils are clean & the
airflow is right-on, you can begin to check the system's charge.
* There
is a TXV system that has very low airflow, approximately only 300-cfm
per-ton of cooling, they're
only checking the suction pressure & saying the charge &
everything is okay! * That system has a TXV & shows; 98-F
condenser saturation temp & 97-F liquid line temp near E-Coil, a mere 1-F Subcooling for
10 & 12-SEER genl-rule is 10-F Subcooling, it's
undercharged even with a mere less than 300-cfm per-ton cooling load!
Unbelievable, but it's happening out there...
Check the
Superheat & the Subcooling as outlined below and always
compare to the charging
instructions that are with the equipment as some use the Approach
Method
& other methods may vary the operating figures & Target figures
vary somewhat from Super Heat & Sub Cooling
methods!
Those varied methods will usually be close to Super-Heat (SH) &
Sub-Cooling (SC) results. I would always use the SH & SC method in
conjunction with the mfg'ers method to trouble
shoot the refrigerant system.
Let's say with a TXV according to the Target Super Heat &
your collected data indicates a starved evaporator coil & a
normal or slightly off Subcooling, even if you are using a Mfg'ers
Approach Method do NOT automatically believe that it is undercharged.
One company is reportedly having problems with TXVs starving Evaporator
Coils,
or it could be a partially plugged TXV strainer/screen or other
restriction.
-----------------------------------------------------------------------
Quick
Check for Sizing Units to enough Airflow
Actually, even on service calls where there are cooling
problems the ductwork should have a quick Manual D performed.
Then take the
ESP
static pressure & compare to blower graph or chart, also take the
FPM duct velocity.
Then do a quick
estimate of airflow
per equipment tonnage.
To find area of
a
round duct; Duct diam is 7"; 7"X7"= 49-sq.ins., X's .7854 =
38.04845-sq.ins divided/ by 144= 0.2672541-sq.ft. area X's FPM Velocity
600-FPM = 160.35246-CFM X30 = 4,810.5738
each 7" run X's 6 branch runs
= 28,863-BTUH, or airflow for 2.4-ton.
(12,000-BTUH
/400-cfm per-ton = 30-BTU per cfm ratio | / 450 = 26.666-BTUH per-cfm)
That would also
be
good for 2-ton; at 550-FPM velocity X's 0.2672541= 147-CFM X 30 =
4,410-BTUH each run X 6-runs = airflow for 26,460-BTUH.
*Never sell
units requiring more airflow than the duct system will support! - Darrell udarrell
--------------------------------------------------------------------------------------------------------------
To Determine Super Heat
(SH): *** First, the airflow through
the evaporator has to be absolutely correct!
1. Take the Suction Saturation Temperature (SST) reading from
your manifold gauge.
2. Then take the Suction Line Temperature (SLT) as close to the
condensing section just before the serve valve.
3. Take the difference between the above readings (Suction Line
Temp 'minus' Gauge Saturation temp reading) = Superheat
4. When ambient air temperature (Outside air temperature) is 85
degrees or above the Superheat should be 8-12
degrees. Thermostatic Expansion Valves (TEV
/ TXV) should be set for a minimum 8-F Degrees Superheat.
Some Heat Pumps with TXV's are set at 7 to 9-F Super Heat
because they have Suction Line
Accumulators to store any spill-over liquid, which protects the
compressor.
Superheat should be checked as
close to
the inlet of the evaporator refrigerant metering device as possible.
For TXV Subcooling, take the pressure of the liquid line note the gauge
saturation
temperature. Compare it to the actual temperature obtained near the
same point the pressure was obtained. Thermostatic Expansion Valves (TEV
/ TXV) should be set for a minimum 10-Degrees Superheat.
This linked page is strictly a SUPERHEAT TABLE
Print these Tables & use them!
Print this Two linked pdf pages:
Target
Super Heat Chart and this Target Temperature Split for Airflow Chart
Here is a formula for getting
the Super Heat Target - Within normal
perimeters:
((IWB) Indoor Wet Bulb X's 3 -
80 - (OAT) Outdoor Ambient Temp) /
divided by 2 = Superheat Target
5. If Superheat is low then the evaporator is flooding.
Note: Do NOT adjust charge YET.
6. If Superheat is high then the evaporator is starving.
Note: Do NOT adjust charge YET!
7. Do not adjust charge UNTIL Sub-Cooling is checked.
Note: When charging a system using Superheat, you are charging
the unit to the amount of air (CFM) and total heat load that is
crossing the evaporator coil (Thus, the amount of latent and sensible
heat load being absorbed by the evaporator coil).
Note: Do not adjust charge based on Superheat on systems
with Thermal Expansion Valves (TXV, TEV's), (use Liquid Line
Sub-Cooling. TEV’s control the superheat; you should check the
superheat to see if the TEV is working properly. Thermostatic
Expansion Valves (TEV / TXV) should be set for a minimum 8-Degrees
Superheat.
To Determine Liquid Line Sub-Cooling (SC): *** First, the airflow through the
evaporator has to be absolutely correct!
1. Take the high side pressure and
convert it to temperature
using chart or gauge.
2. Then take the temperature of the liquid line as close to
the condenser as possible..
3. Take the difference between the above readings. (Saturation
Temp – Liquid Line Temp.). Note: liquid line temperature at the
evaporator should be within 2 degrees of liquid line temperature at
condensing unit. If not, could be a restriction or line set too long.
4. Sub-Cooling with a TXV, should be around 9 to 15-F degrees,
always check
with the mfg’ers for correct SC
5. Then using the information from Superheat and Sub-Cooling we
can have some idea where to look for a problem.
Example:
Suction Line Temp is ------- 60 degrees @ condenser
Gauge Suction Pressure is ------76-psig ---- 45 degrees, Read Gauge
Suction Saturation Temperature (SST)
60 degrees – 45 degrees = 15 degree Superheat - Adjust charge to the
mfg'ers Super Heat settings
Liquid Pressure is ------------226-psig --------110 degrees, Read
Gauge - Liquid Saturation Temperature (LST)
Liquid Line Temp (LLT) is -------------95 degrees
110 degrees – 95 degrees = 15 degree Sub-Cooling - Adjust Refrigerant charge to the mfg'ers SC
settings
No
mfg'ering specs available > General Subcooling specifications for
TXV systems:
13-SEER
& above 3 to 11-F; Subcooling > need mfg'ers data
10 to 12-SEER; 10-F Subcooling
8.5 to 9.5-SEER; 15-F Subcooling
Pre- 1985, 8-SEER or less; 20-F Subcooling
======================================================
*You could ballpark the CFM
using the static test & a air handler graph. You could measure
the CFM delivered to each room with a hood Alnor Balometer, it's
usually the best instrument to use, but not cheap. Measuring the air
velocity is a bit tricky because you have to use the
diffuser data which you don't always have available.
A rough ballpark formula to get the CFM: CFM = (velocity in (FPM) Feet
per Minute times the square footage of the duct area, you have to have
& use the diffuser data & get velocity there -for operating
conditions.) Taking the manifold gage head pressure & gage
condensing temp, is important data. Coupled with a TH condenser
temp-reading, if the condenser gage
pres/temp is too high compared to the TH reading, there may be
non-condensibles in the system.
Also,
there is a legitimate formula I use to determine the operating BTUH it
is delivering at all the data taken. All the mfg'ers ought to list the
condenser temp-split (it varies with EER & SEER) just like they
list the indoor split, it is valuable trouble shooting info.
You can also use the condenser temp-split (it contains both Latent
& sensible heat) combined with the indoor data to plot the indoor CFM. I
was never good at math, but those
equations have to balance, & they do work!
--------------------------
An Affordable Test
Instrument You Need!
All I had was the
Sling Psychrometer & spinning it was a bit time consuming, but I
used it religiously, it is information you need.
The Testo 605-H2 Humidity Stick
(wet
bulb), displays relative humidity,
air temperature and wet bulb temperature.
It is very affordable & because of its potential to help deliver
tons of other data everyone should have one!
For more information on it:
http://www.amazon.com/Testo-605-H2-H.../dp/B000774B6A
The other test data you need is the system's CFM airflow through the
evaporator coil, then with software I have you can peg the BTUH the
operating unit is delivering under those conditions.
Add to that a low cost Magnehelic gauge to read static pressures to
compare with mfg'ers blower performance charts; plus a velocity meter
& you have a ballparked CFM to plug into for the BTUH.
We could easily provide a detailed psychrometric print out of
exactly what the operating system is delivering including condensate
lbs/hr, & actual sensible & latent cooling BTUH & Ratio,
every data
detail imaginable.
============================
It is
important to understand that "equipment ratings are only the
'potential efficiency' of that component of the system under perfect
conditions." Over half of the system’s efficiency depends on
correct equipment sizing run-time,
on the duct system sizing, i.e., on the quality of the complete
field-installation!
Especially
if your system is oversized or there are a lot of low AC load days use
an adjustable differential room TH.
TH
Differential: Differential is defined as
the difference between the cut-in and cut-out
points as measured at the thermostat
under specified operating conditions. For example, if the thermostat
turns the
COOLING EQUIPMENT on at 78-F & OFF at 76-F that is a 2 degree
differential setting; one has a 4-F adjustable differential. This is a
good way to control high humidity problems & also improve SEER
performance.
What you want & need is right sized equipment operating
at
its
optimal ratings within varying conditions, for your optimal comfort
and
savings.
====================================================
TROUBLE
SHOOTING TXV VALVE SYSTEMS
Bulb location:
Some Mfg’s have there preferences, but a good rule of thumb is 10 or 2
O’Clock,
away from headers and heat exchangers, on a smooth clean surface.
Also, make sure the
cap tube is on top (horizontal
or vertical and never upside down).
Pressure drop:
TXVs like to have at least 100-psi
pressure drop across them to operate correctly. A
solid column of liquid (at the valve) is also a requirement.
Flood back:
Always make sure you have "the correct CFM airflow"
(clean coils," Clean fan blades
& fans running on correct speeds
and in the right direction) before you try adjusting a valve.
No flow: A plugged
screen is rare in air
conditioning, but happens often in refrigeration. I have
seen the external
equalizer tube leak through in liquid
form and give the bulb a false reading (which causes hunting more so than no flow).
-------------------------------
TXV Partially
plugged, downstream from service port, filter-dryer or screen at
Compressor Inlet, therefore TXV is Wide Open flashing some vapor & cooling coil is starved of
liquid refrigerant:
Suction
Low-Side
Suction-PSIG -
Normal to High
|
SUCTION
Super-Heat -
HIGH
|
High-Side
Head-Pres. -
LOW
|
Liquid-Line
SUB-Cooling
-
NORMAL
|
Cond.-Unit
Amp-Draw -
LOW
|
In
HVAC-TALK These Posts Illustrate and Discuss these Test Results
Lennox TXV Subcooling -
Approach Method - pdf P- 8
http://www.davelennox.com/pdfs/installation_maintenance/Lennox-12ACB-IOM.pdf
Always check both SH & SC for trouble shooting
comparison to normal
parameters!
---------------------
There is a concern that we need more accurate means to achieve an
accurate target sub-cooling temperature under varying conditions.
First, before any operating
performance feedback data is recorded, the
following tests & corrections must be performed. We need to make
certain that the airflow is checked to be within the proper parameters
and that the ductwork is properly sized and sealed with return air
grilles in every room at the ceiling level. In addition, if possible
for the cooling mode, Supply Air Diffusers should also be at the
ceiling level.
Accurate tests should also be made, to determine whether proper airflow
CFM is being delivered, as well as into each room.
The manufacturers could be of great help in this respect, if they would
list the Delta-T of the condensing unit at different BTUH load output
levels, also at various outdoor ambient temperatures.
I believe that with adequate test data feedback the subcooling could be
targeted within plus or minus 1 or 2 degrees Fahrenheit, which would be
a two to four degree differential.
That would be more accurate & concise a temperature target than
present subcooling temperature targeting methodologies.
Additionally, I would consider using the Lennox Approach Method to help
select the Subcooling Method.
The Lennox Approach Method subtracts
the Outdoor
Ambient Temperature from the Liquid Line Temperature (LLT), whereas,
the subcooling temperature targeting method subtracts the Liquid Line
Temperature near the evaporator from the Condenser Saturation
Temperature (CST). I do not see why the Lennox Approach Method would
not help pinpoint the subcooling target on other systems. The Indoor
Heatload has to be part of the equation; there are other factors to
incorporate as well.
Possible
Diagnosis
using Super-Heat and Sub-Cooling:
If Superheat is high and
Sub-Cooling is low:
Charge must be adjusted. System is Undercharged.
If superheat is low and sub-cooling is high:
Charge must be adjusted. System
is Overcharged.
If Superheat is very high
and
Sub-Cooling is a little high:
Could have blockage in
coil, TXV strainer screen - settings, etc., orifice, filter dryers etc.
If Super-Heat is low
and Sub-Cooling is low:
Piston orifice could be
too big, or some, in backwards, there is no orifice in the unit or the
orifice is stuck and refrigerant is bypassing it.
To Determine Delta T (Td) (Temperature difference across the
coil):
1. While unit is running take the temperature of the air in the
supply plenum near the coil (approx. 12 inches.)
2. Then, while the unit is still running, take the temperature of
the air in the return plenum near the unit.
3. Then take the difference between the above readings.
4. Should be around 15-18 degrees. Use
linked Chart above!
5. If to low then coil might not be seated in pan correctly - air
bypassing cooling coil. (Assuming superheat and Sub-Cooling are OK.)
6. A TXV's normal Superheat setting is
between 8-F to 12-F. There must be a full
liquid stream to the TXV!
With a TXV metering device
if Superheat is too high
say, 20-F or above — look for, suction line restriction, plugged
cap tube/orifice./liquid line, hot gas discharge line restriction,
filter dyer, downstream of suction service port, or compressor screen
restriction or
inefficient compressor.
-------
What are the proper methods to determine operating superheat,
sub-cooling?
Superheat at the evaporator should be
checked as close to the end of the coil as possible (preferably near
the expansion valve thermal bulb). Convert this to saturation
temperature and compare it to the actual temperature obtained near the
thermal bulb. Take the suction
pressure at the
service valve and convert it to saturation temperature. Compare this to
the actual temperature obtained approximately six inches out on the
suction line.
Subcooling should be
checked as close to the condenser as possible & then as close to
the TXV as possible noting the difference.
============
Carl Bergt, Principle
Engineer at Rheem writes:
Mr. Wolok: Your inquiry concerning subcooling as been forwarded
to me. From the information that has been provided to me,
it appears that you are searching for a recommended subcooling level
for residential products. As you can tell from the variety
of responses you have received, subcooling, at the outdoor condensing
unit cannot be clearly defined. Simply, subcooling is a
function of many factors that includes; the outdoor unit, line size
between the outdoor condenser and indoor coil, total refrigerant line
lengths, number of bends in the refrigerant lines, refrigerant
utilized, ambient, vertical separation between the outdoor and indoor
components, and flow control.
To my knowledge, all split residential products require subcooling at
the outdoor unit. This includes systems that utilize TXV,
capillary tube, or fixed orifice indoor flow controls. If
you are looking for a simple solution, I would suggest you measure the
subcooling level at the indoor coil before the expansion device.
Assure you have at least 4-6 deg F
subcooling and you should find
proper operation for any given installation. This assumes
that
you will measure subcooling at ambients or operating conditions that
are somewhat close to your normal operating conditions and your
refrigerant line sizes and lengths are within the manufacturer's
recommendations. (Use my SC temps
above.)
Measuring subcooling "at
the
indoor coil" takes into account many of the
variables noted above. The ultimate goal is to assure you have
liquid refrigerant at the expansion device using reasonable subcooling
levels that allow for efficient unit operation. What you
will
discover is that the subcooling at the outdoor unit will vary
depending on the installation and application. If subcooling is
measured at the outdoor unit, you will have to account for the
variables noted earlier to determine the correct level.
-----------------------
My response to an
HVAC Forum question on BTU & Tonnage Ratings:
Three ton is 36,000 BTUs.
The units are Rated in Nominal Tons per hour.
However, the nominal BTU/hr rating of some range from 36,000
down to around 34,000-BTU/hr.
Additionally,
with high indoor temperatures & very high humidity a nominal
36,000-BTU/hr could go considerably higher.
Example, Goodman Expanded Data: a 3-ton condenser 13-SEER
GSC130363A, with a 4-ton evaporator coil:
1434-cfm or 478-cfm per ton of cooling
85 OAT Outdoor Ambient Temp
80 IDB Indoor Dry Bulb
71 IWB Indoor Wet Bulb or 63% Relative Humidity
Nominal BTU/hr of 39,500
At 75 OAT outdoor Ambient Temp
other figures the same, nominal listed @ 40,500-BTU/hr. (At ARI
Conditions)
Moderate
outdoor temps coupled with high indoor temps results in a high latent
humidity
heatload through the evaporator coil which boils refrigerant at its
fastest
rate, which transfers more heat outdoors per unit of time.
- udarrell
------
That is why we should NOT be upsizing equipment for latent heat
removal; because
the A/C system increaFirst, ses its latent capacity to handle that
load. When
the unit is upsized the run-time operating-cycles can be way too short
for effective latent heat
(humidity) removal.
---------------------------------------
Determining
which metering
device TXV or Fixed Orifice the system has without physically looking
If you do not absolutely know whether the metering device is a TXV, or a fixed orifice device or cap tube.
Hook up your manifold gauges, block off considerable condenser air intake for a short time. If suction pressure changes it's a fixed piston or cap tube If only the high-side goes up, you have a TXV.
Have things with you in your van or truck to block-off the condenser air for a short time. Check every time you are not certain what metering device it has. There may be a lot of guessing in the future.
Do this procedure on known metering devices to observe the difference. Report back to me how well it works for you.
In some situations, that could save you from cutting a hole in the plenum.
Squirrel cage wheels with forward curved blades on residential systems unload when discharge air is blocked off too much & will overload when there is no static pressure. There is a preferable ESP range for each Air Handler blower design, that ought to be listed on the blower; they vary at the point of serious unloading. If you amp-probe check enough of those blower motors, if the amp draw is too low according to its rating, you can begin to tell that the External Static Pressures (ESP) is too high. Additionally, mfg'ers could list the amp draw at various design ESP numbers, then we could amp-probe & know if it was too far above the amp rating, a duct maybe off, if amp reading is too low, it is time to check all static pressures & delivered CFM to each room.
I lot of us used to set a nearly empty R-22 cylinder on top of a condenser to warm it a little. Back then fan motors had more HP & higher amp draws, therefore it didn't seem to cause any harm, just more noise.
Back in the 1960's & 1970's there were a fair number of TXV metering devices & some table top condensers' that had the fan underneath blowing up through the coils. Well, where there were cottonwood trees, nearby clothes dryer lint vents, or a lot of leaves or other debris under the unit, the fan motors would be blocked overload & burnout.
I don't understand the engineering genius of that moronic design.
However, on hot days & a heat-loaded E-Coil, You could move your wrist over the condenser from outlet up to inlet, & tell if the liquid was taking up too much area of the coils; an overcharged system. - udarrell --------------------
Gurgling sounds at TEV: Low
evaporator heat-loads lead to reduced liquid line mass and increased
evaporator mass could be due to airflow problems. Eliminate low
evaporator heat-loads before looking into adjusting the refrigerant
charge. Gurgling -
pulsation noises in Liquid Line at the expansion device can
be
caused by low evaporator circuit heat-loads, low charge, and/or
non-condensibles and moisture in the system.
Unbalanced airflow
through
the various distributor circuits of the evaporator coil will cause the
TEV to close down refrigerant flow starving the coil.
Piston-flow-rators will make it impossible to properly charge the
system and cooling will be greatly compromised unless you eliminate the
cause! "Put your ear on the liquid line at the evaporator coil."
On
every Rheem
condenser cover it lists
"non-condensibles and or
moisture" as causes for a gurgling or pulsating noise at the expansion
device. The entire evaporator circuits, may not become active for
various reasons, - "the entire coil must become fully active for
efficient performance."
The
purpose of
these recommendations is to provide liquid refrigerant at the expansion
device and provide efficient operation. Hopefully, this will aid your
research. If I can be of additional assistance, contact me.
-----------------------------------------------------------
Too
many do not
properly
purge & evacuate contaminated
central air conditioning systems.
The
Triple Evacuation Method is normally done on refrigeration systems,
R-410a systems require it on central air
conditioning systems:
First,
remove any valve cores with a special valve core remover this
will
speed up the evacuation time. Back service valves two turns off their
back seat.
1)
Re-claim unit charge (Recover all the refrigerant)
2) Charge
system to 150 PSIG with dry nitrogen and leak test
3) On
contaminated systems replace the filter dryers. Then Repair all
leak(s)
4)
Evacuate system to 500 microns valve off & see if it holds 500
microns for ten minutes, if it holds, break
the vacuum with
dry nitrogen
5)
Evacuate system to a deeper 400 microns, valve off vac pump, &
again break the vacuum with
dry
nitrogen
6)
Evacuate system to 400 microns and & then Check to see if it holds.
(Recharge with fresh
clean refrigerant)
7) Check
to see if the Supply and Return air ducts were correctly sized &
sealed by the original installer.
If a vacuum pump will not evacuate a system below 1500 microns there is
a problem with the pump itself, a leak in the system, or moisture in
the system. Moisture is most likely because water vaporizes at
1500 microns.
Many HVAC
contractors will consider this excessive time & effort
for contaminated
residential
air conditioning systems, however it is a must for low temp
applications.
The
“micron” is a metric unit of measure for
distance. The micron is a unit of linear measure; one micron equals
1/25,400ths
of an inch. Modern high capacity vacuum pumps help speed up the
evacuation process.
When
a system has been evacuated below 500 microns, the pump is valved-off
with the micron gauge connected, if the vacuum rises to 1500
microns and stops, there is moisture remaining in the system. If it
rises above 1500 microns & continues to rise there is a leak. You
should allow at least 15 minutes after the pump has been shut off an
accurate micron gauge reading. When a
system will not evacuate below 1500 microns there is either a lot of
water or there is a system leak.
===============================================================
Check
Return Air
(RA) at grille & at entry of blower for heat gain, due to hot
Return Air leaks.
Where airhandlers' set over Return Air Chambers check for
air leaks through the sheet rock & down the wall studs from
the
attic - this is a fairly common condition that will overload the AC
system!
Below
is an outstanding PDF "Basic AC Overview - Specifications VS. Reality"
by John Proctor, P.E., Proctor Engineering Group, LTD:
HVAC TECH
PERFORMANCE RATINGS "AC
Specs vs Reality" PDF
EFFICIENT
INDOOR COMFORT
FREE HVAC Resources
for Professionals
There
are a multiplicity of things that affect subcooling, first, airflow
must
be correct; Supply Air Return Air sealed & correctly sized!
I
would also add that we need effective ways to determine the BTUH that
the
system is delivering while we are recording superheat & subcooling
temperature
data. We need helpful condenser-temperature-split performance
data from from all of the mfg'ers to make this operating BTUH data more
accurate &
easy to acquire. See my other pages for this test method. -
Darrell
Study the Failure Rate
Graph in the pdf above!
It is a well-known fact in the industry that a large percentage of
compressors being replaced are replaced due to improper diagnosis, NOT
compressor failure!
Focus on Energy -
Efficient Heating & Cooling Initiative
- Target Temperature Split
for Airflow - PRINT Charts
On above linked page scroll down and Click - Airflow and Refrigerant Tables
- the Super Heat Table does NOT comport with other methods! - Darrell - udarrell
DISCLAIMER:
Any
of
the HVAC companies I list on any of my web pages have nothing to do
with the information I post on any of my Web pages nor do I assume any
responsibility for how anyone uses that information.
All HVAC/R work
should always be done by a licensed Contractor! This information is
only placed on these pages for your understanding & communication
with contractors & techs.
This
information is for the edification of contractors and techs. I
am NOT liable for your screw-ups, you are liable for what you do! -
Darrell Udelhoven (U-dl-hoven)
Darrell's Refrigeration Heating and Air Conditioning -
Federal
Refrigerant Licensed - Retired
HVAC Contractor
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PEOPLE EMPOWERMENT PAGES
Links to my pages
Darrell Udelhoven (U-dl-hoven) -
Empowerment Communications
Covering The Real Political
Issues
Darrell
Udelhoven |