First Responder, Military, and Senior Discounts.
First Responder, Military, and Senior Discounts.
The new system is installed.
The brazing is finished.
The vacuum held.
The electrical is connected.
The drain is built.
The thermostat is on the wall.
Someone turns the system on.
The condenser starts.
Cold air begins coming from the vents.
And everybody immediately starts putting tools in the truck.
Absolutely not.
The system starting is not the end of the installation.
It’s the beginning of commissioning.
This is where we prove that everything we just spent the day installing actually works.
Not:
“It runs.”
Not:
“It’s blowing cold.”
Not:
“Pressures look good.”
Not:
“We’re good.”
Show us.
Think about what just happened.
We disconnected and replaced major pieces of equipment.
We opened the refrigeration circuit.
We brazed refrigerant lines.
We changed electrical connections.
We connected ductwork.
We built or modified a condensate drain.
We installed safeties.
We wired controls.
We configured a thermostat.
We may have changed airflow settings.
We may have added refrigerant.
We touched nearly every system required for that air conditioner to operate.
Now we test everything we touched.
Our installation SOP requires commissioning after evacuation, including checking refrigerant operation and charge, drain operation, temperature split, float switches, and heat mode.
Commissioning isn’t an optional final flourish.
It is part of the installation.
Don’t make startup dramatic.
Before energizing the equipment, stop for a minute and look at your work.
Are the electrical connections complete?
Are panels installed where they need to be?
Are the correct breakers and disconnects in place?
Are the low-voltage connections correct?
Are the refrigerant valves ready to be opened?
Has evacuation been completed and verified?
Is the condensate system ready?
Are tools, screws, rags, wire clippings, or anything else somewhere they absolutely should not be?
Has the air handler been configured?
Has the thermostat been configured for the equipment?
Do a visual inspection.
Then start it.
Five minutes spent looking before applying power can save a control board.
We covered this in Installation Standards, and we’re going to say it again because it matters.
Our SOP requires:
500 microns.
And a:
10-minute hold.
Not:
“Pump ran for an hour.”
Not:
“Gauge went negative.”
Not:
“I left it on while we ate lunch.”
Time does not prove dehydration.
Microns do.
And reaching 500 microns isn’t enough by itself.
The hold matters.
If it doesn’t hold, figure out why.
Don’t release the charge because everyone is getting tired and we’re already late.
A problem does not become less of a problem because it’s 4:30.
Once evacuation has been completed and verified, release the factory refrigerant charge.
Then allow the system to operate and stabilize before deciding anything about refrigerant charge.
Our SOP requires refrigerant operation to be checked against the condenser manufacturer’s guidance and calls for adding or recovering refrigerant as necessary.
This is where measurements begin.
We do not commission systems by pressure alone.
Pressure is information.
It is not the entire refrigeration system.
Our SOP calls for checking system charge according to the condenser guide and includes target commissioning values of approximately:
Subcooling: 10–15°F
Superheat: 8–12°F
with adjustments made as necessary.
The important words there are:
According to the condenser guide.
Different equipment may require different procedures.
So use the manufacturer’s charging procedure for the equipment you’re standing in front of.
Not what the last unit needed.
Not what you remember from another model.
Not what somebody told you eight years ago.
And definitely not:
“Beer can cold.”
Don’t collect numbers just so there are numbers on the paperwork.
Understand what they are telling you.
If something doesn’t make sense, investigate it.
If the refrigerant readings don’t agree with the air temperatures, don’t simply choose the number you like better.
If the system doesn’t stabilize where expected, don’t immediately start adding refrigerant.
The entire point of commissioning is to catch problems before the customer does.
Slow down.
Think.
Measure.
Verify.
Our SOP requires a supply-to-return temperature measurement during commissioning, with a target split of approximately 15–20°F.
Use temperature probes.
Take an actual measurement.
Your hand is not a temperature probe.
Neither is your face.
“Feels cold.”
is not an acceptable commissioning result.
Record the return temperature.
Record the supply temperature.
Calculate the difference.
Does it make sense?
Good.
If it doesn’t:
Find out why.
A refrigeration system cannot be properly evaluated without proper airflow.
We already configured the air handler during installation.
Now verify the result.
Listen to the blower.
Listen for abnormal noise or vibration.
Check the supply air.
Look for obvious airflow problems.
Make sure the system isn’t telling you something is wrong.
A perfectly charged refrigeration circuit cannot fix bad airflow.
And refrigerant should never be used to compensate for an airflow problem.
Fix the airflow problem.
Remember the temporary cap we installed while treating the existing drain?
Remove it.
Our SOP requires us to remove the outside drain cap, prime the trap with water, and verify condensate flow during commissioning.
Do not forget the cap.
That would be—
how should we put this—
counterproductive.
This seems to offend some technicians.
They build a drain.
They look at the drain.
They admire the drain.
Then they announce:
“It’ll drain.”
Wonderful.
Prove it.
Prime the trap.
Run water through it.
Watch where the water goes.
Check the pan.
Check the fittings.
Check for leaks.
Check the outside termination.
Make sure water actually exits.
Gravity is free.
Testing it is also free.
Use both.
Our installation SOP specifically requires float switches to be tested during commissioning.
Notice the word:
TESTED.
Not:
Installed.
Not:
Wired.
Not:
Looks good.
Tested.
Activate the float.
Verify that the system shuts down the way it is supposed to.
Then reset it and verify normal operation returns.
A float switch that doesn’t stop the system is not a safety device.
It’s an ornament.
And we don’t install decorative float switches.
While testing the drain, look around the air handler.
Look underneath it.
Look at the secondary pan.
Look around the drain fittings.
Look at the coil cabinet.
Look at the penetrations.
Look for sweating.
Look for leaks.
Look for anything that doesn’t make sense.
Water problems have a wonderful habit of starting small and becoming extremely expensive after we leave.
Catch them now.
Yes.
Heat.
Yes, even if it’s August.
Yes, even if it’s 96°F outside.
Our installation SOP requires heat mode to be tested before the installation is considered complete.
The first cold morning of the year should not be our commissioning procedure.
Turn the thermostat to heat.
Verify the system responds correctly.
Verify the controls operate correctly.
Verify the heat source operates.
Then return the thermostat to the appropriate setting.
“We’ll know in December.”
is not an acceptable test.
The thermostat is the customer’s primary interface with the system.
Make sure it actually controls the equipment correctly.
Cooling.
Heating.
Fan.
Stages where applicable.
Our installation SOP requires the thermostat to be configured for the equipment and calibrated within approximately ±1°F of a reference thermometer.
If it’s a smart thermostat, make sure the setup is completed.
If it’s communicating equipment, make sure the equipment is recognized and configured correctly.
If something is wrong:
Fix it now.
Do not teach the customer how to work around something we installed incorrectly.
Startup is a good time to verify the settings you made during installation.
Our SOP requires AHU dip switches and control-board settings to be configured according to the manufacturer’s manual.
Verify them.
If the equipment isn’t behaving the way you expected, don’t immediately assume the equipment is defective.
Go back through your work.
Settings.
Wiring.
Airflow.
Thermostat configuration.
Connections.
Then start diagnosing.
New does not mean defective.
And new definitely does not mean we couldn’t have made a mistake.
Once the equipment is running, pay attention to electrical operation.
Listen.
Look.
Measure where required.
Make sure components are operating normally.
Nothing should be buzzing, chattering, overheating, vibrating strangely, or doing anything that makes you say:
“That’s probably fine.”
If something catches your attention, investigate it.
Your instincts are useful.
Your meter is better.
Do not turn the system on for 90 seconds and declare victory.
Let it operate.
Give temperatures time to stabilize.
Give refrigerant operation time to stabilize.
Give the drain an opportunity to prove itself.
Listen to the system.
Watch it.
This is the first time the entire installation has operated together.
Pay attention.
You’re not waiting for it.
You’re observing it.
This is one of the best times to inspect your work.
Start inside.
Air handler.
Duct connections.
Drain.
Electrical.
Panels.
Noise.
Vibration.
Airflow.
Then go outside.
Condenser.
Refrigerant lines.
Electrical.
Lineset penetration.
Noise.
Vibration.
Drain termination.
Look at everything while the system is actually operating.
Things behave differently when they’re running.
That’s why we test them running.
Commissioning isn’t just filling in boxes.
If the numbers look good but something sounds wrong:
Investigate it.
If the system is cooling but the blower is vibrating:
Investigate it.
If the refrigerant readings look reasonable but the airflow seems terrible:
Investigate it.
If the drain works but water is appearing somewhere else:
Investigate it.
If something doesn’t look right:
Investigate it.
You are standing at the best possible moment to fix it.
The tools are already there.
The equipment is already open.
The installers are already on site.
Tomorrow it becomes a callback.
Today it’s simply part of the installation.
Sometimes commissioning finds a problem.
Good.
That’s what commissioning is for.
Maybe there’s a refrigerant issue.
Maybe there’s an electrical fault.
Maybe the drain isn’t working correctly.
Maybe a component isn’t responding.
Maybe something was wired incorrectly.
Maybe we made a mistake.
Maybe the equipment itself has a problem.
Our SOP requires problems discovered during startup to be addressed and reported to the office, with follow-up needs documented.
Don’t hide it.
Don’t hope it fixes itself.
Don’t reset something six times until it finally runs and then sprint toward the truck.
Find out why.
This deserves to live in the Operations Manual.
If equipment faults during commissioning and cycling power makes the fault disappear, you have learned one thing:
Cycling power made the fault disappear.
You have not necessarily fixed anything.
Look at the fault.
Look at the manual.
Check the wiring.
Check the configuration.
Understand what happened.
Then decide whether the system is actually ready to be handed over.
Commissioning also requires judgment.
A measurement being slightly different from an example target does not automatically mean something is wrong.
Conditions matter.
Equipment matters.
Manufacturer specifications matter.
That’s why we use the actual equipment documentation and look at the system as a whole.
We’re not trying to manipulate every number until the screen displays something aesthetically pleasing.
We’re trying to verify that the equipment is installed, configured, charged, draining, controlling, and operating correctly.
Know the difference.
If you measured it:
Record it.
Temperatures.
Refrigerant readings.
Anything required for the job record.
Our SOP requires job details and refrigerant information to be completed and the installation documented before completion.
The paperwork is not separate from commissioning.
It proves commissioning happened.
And it gives us a baseline.
Years from now, somebody may be standing in front of that same system trying to understand how it is performing.
Give them useful information.
Photograph the completed installation.
Not just the pretty condenser.
Air handler.
Drain.
Duct connections.
Electrical.
Thermostat.
Equipment labels.
Anything unusual.
Anything another technician might need to see later.
Our SOP requires completed-job photos to be sent to the office.
Take pictures before everything is closed up if they document something important.
The camera is part of the job.
Use it.
Notice when this happens.
After testing.
Not while the system is still pulling down.
Not while somebody is still trying to verify charge.
Not when the float switches haven’t been tested yet.
There is a psychological shift when everyone starts loading the truck.
The job feels finished.
People start mentally leaving.
That’s when things get missed.
Finish commissioning.
Then clean up.
Once we’re satisfied with the system, walk the customer through it.
Our SOP requires us to demonstrate operation, help connect the thermostat to Wi-Fi and download the app, provide the appropriate permit/warranty/maintenance information, and answer the customer’s questions.
This is another opportunity to notice something.
Operate the thermostat with them.
Show them the system.
Listen.
Look.
If something behaves strangely during the walkthrough, don’t ignore it because you already packed the gauges.
The customer hasn’t accepted the system yet.
We’re still commissioning.
Before pulling out of the driveway, verify the system is operating in the mode the customer expects.
Check the thermostat.
Check that panels are installed.
Check the drain one more time.
Look around the air handler.
Look around the condenser.
Listen.
Then ask yourself:
Do I have evidence that this system is operating correctly—or do I just know that it turned on?
Those are not the same thing.
Because installation mistakes happen.
Even to good installers.
A wire can land on the wrong terminal.
A switch can be set incorrectly.
A drain fitting can leak.
A float can be wired incorrectly.
A thermostat can be configured wrong.
A refrigerant charge can need adjustment.
A duct connection can leak.
Something can be missed.
Commissioning is not an insult to the installer.
Commissioning is how a good installer catches his own mistakes.
That’s professionalism.
This is really what the entire section comes down to.
The customer should not discover:
That heat doesn’t work.
That the drain leaks.
That the float switch doesn’t shut the system down.
That the thermostat was configured incorrectly.
That the system is making a strange noise.
That something wasn’t connected.
That the system isn’t performing correctly.
We should discover those things.
That’s why we’re still there.
We’ve already killed this phrase in maintenance.
Now we’re killing it in installation too.
Yep, it’s running.
Great.
Is it configured correctly?
Is airflow correct?
Is refrigerant operation correct?
Is the temperature split reasonable?
Does the drain work?
Do the safeties work?
Does heat work?
Does the thermostat control everything correctly?
Are there leaks?
Are there abnormal noises?
Did you document the readings?
Did you inspect your work while it was operating?
If the answer to those questions is yes:
Now we’re getting somewhere.
Startup is not the moment the system turns on.
Startup is the process of proving that the system we installed operates the way it should.
Testing is not something we do when we suspect a problem.
We test because we don’t want the customer to be the person who finds the problem.
And commissioning is not paperwork.
It’s the final quality-control process for the entire installation.
So:
Pull the vacuum.
Verify the hold.
Release the charge.
Start the system.
Let it stabilize.
Check refrigerant operation.
Measure temperatures.
Verify airflow.
Prime and test the drain.
Test every float switch.
Test cooling.
Test heat.
Verify the thermostat.
Verify the equipment settings.
Listen.
Look.
Measure.
Document.
Then walk the entire installation one more time.
Because the standard isn’t:
“It turned on.”
The standard is:
“We tested it, and we know it works.”