HVAC Zoning: Bypass Dampers & Dump Zones

HVAC Zoning Basics - Bypass Dampers Dump Zones

HVAC Zoning: What to Do with That Extra Air

Last week we did a zoning basics blog post on zoning for residential homes.  This week on the Fox Family Heating and Air Conditioning blog I want to touch on a little more technical side of the HVAC zoning setup: bypass dampers and dump zones.

Some HVAC installers say you can’t truly set up a unitary ducted HVAC system like the ones most of us in the United States have set up in our homes.  Remember, zoning is for homes that have two thermostats, one upstairs and one downstairs.  They typically allow one HVAC system to heat or cool one zone or the other, but not the whole house at one time.

If you’re an HVAC technician, let me know in the comments down below how you like to set up bypasses and dump zones to get rid of the extra air zoning creates.  I’m sure it’s a little different all around the world, and we’d love to hear about it!

Bypass Dampers on High-End Equipment

Trane and Carrier have some nice setups when it comes to their variable speed systems and modulating dampers that open and close strategically, allowing you to really dial in the rooms you want to condition and when.  But buying one of those systems is no joke.  Currently, I’d say only about 7% of the market is buying this high-end equipment.  They really are advanced technology compared to the traditional zoning equipment Americans are used to in their homes today.  But I’m sure this technology will be mainstream soon enough!

Traditional zoning uses two thermostats.  These thermostats can be smart Wi-Fi stats or standard digital programmable stats.  And those two stats talk to a main zone board at the furnace or air handler.  That main zone board then tells the air handler when to come on.  It will trigger air conditioning or heating mode as well as which floor to have come on.

Zoned systems are purposely designed to be about half a ton larger than the largest zone in the house.  Last week’s example of a home with two floors, one at 1150 sq. ft. and one at 800 sq. ft., would be sized at 2.5 to 3 tons depending on insulation levels and other load characteristics.  A system that large can produce 1000 to 1200 cfms.

HVAC Zoning: Directing Extra Air

That smaller 800 sq. ft. zone cools the bedrooms and bathrooms upstairs as well as the laundry room.  But 1000 to 1200 cfms is way too big for 800 sq. ft.  So, what do we do with the extra air?  It should be bled off to another area of the house.

There are a few choices as to where to disperse that extra air:

  • We can create a barometric bypass back to the return plenum or return grille.
  • A bypass dump zone can be created in another portion of the house.
  • Or my favorite, bypass the air to the other zone through dampers set up properly for this.

Option #1 – A barometric bypass straight back to the return plenum

In my opinion, this is the worst way to get rid of the extra air because it sends it immediately back to the return through an 8 to 10” duct with a barometric damper that cracks open with the “extra” air pushing against it.  The more “extra air” there is, the more the damper opens allowing air back to the return plenum.

This superheats the return air in heating mode, and supercools the return air in cooling mode.  How does that affect the system?  In the heating mode, if we have 65-degree air initially entering the return side of the furnace or air handler, it goes through the furnace and gets heated up about 40 degrees to a supply air temperature of about 105 degrees, where that air exits the registers in each room.

If one zone is open and the other closed, the extra air gets sent through an 8 to 12” inch duct immediately back to the return plenum and mixes with that 65-degree air, essentially raising the return air temperature to 70 to 75-degrees.  This air then gets heated up to 115 degrees which now heats up the air in the return plenum to 80 to 90 degrees.

High Temps

On and on this goes, until the system has superheated the return air so high the high limit switch turns off the burners because the supply air is too hot.  And that’s hot because those high limits usually shut the burners off at 165 to 200 degrees.  What does that mean the return air rose to?  125 to 160 degrees!  I see it all the time.

The same thing happens to the evaporator coil.  When the cool supply air gets sent back to the return plenum and recycles over and over, that air gets so cool the evaporator coil eventually freezes.  This blocks the airflow, causing even more problems.

Option #2 – A dump zone

In this scenario we send the extra air through a duct about 8 to 12” to a dump zone, or another section of the house.  I’ve worked on crews that chose to dump the air into a living room, and others that dumped it into the foyer with a 25-foot ceiling!  I’ll admit, that was pretty scary installing that one.  Trusting those ceiling joists to hold as was I was cutting into that 20×20 can was a little intimidating.

I wasn’t the lead installer on those jobs.  In fact, I was just a helper at that time.  Those jobs taught us that the air being dumped in that living area was making those rooms uncomfortably warm or cold depending on the season.

Having learned our lesson, we started dumping that air to the end of the return duct to either a “Y” where the duct meets the can, or a collar cut into the return air can itself, at the ceiling.  I like cutting it into the can because the cold or hot air gets to mix a little more with the return air before being drawn through the furnace or evaporator coil again.  This way the superheating or supercooling doesn’t happen as fast or as easily.

Option #3 – Bleed off to the other zone through dampers

The option that we take at Fox Family is to bleed off the air to the other zone through a small gap left as the damper closes.  We don’t let zone 1 or zone 2’s damper close all the way.  And there are settings on the Honeywell AR Dampers that meter the correct amount the installer decides.

Let’s returning to the house that has 1150 and 800 sq. ft. zones.  If the smaller zone is calling for cooling, the other 400 cfms is redirected to the bigger zone.  This way it won’t be dumped into one single room.  Instead it will get distributed evenly throughout the larger zone through several registers.

The great thing is, this air won’t over-cool or overheat that unused zone.  This allows the system’s static pressure to be regulated at a level that’s closer to manufacturer specs.  This extends the life of the system.

HVAC Zoning Basics can be Complex

Ductless systems are becoming more and more popular in America.  They’re great for zoning individual rooms one at a time.  For those of us who already have supply registers and ducts leading to every room in the house, zoning is still a complicated issue.  Taking care of the HVAC system is the main priority for an HVAC installer.  There are some folks who will just hack it in, and others who try to do it right.

Weigh In

As always, I would love to hear your strategies and comments about how you incorporate HVAC zoning into a house.  All of us are a little different because we work in different parts of the world.  So let me hear from you below in the comments section.

Thanks so much for stopping by, and we’ll see you on the next blog post!

Four Reasons Why Your AC Circuit Breaker Keeps Tripping

circuit breaker tripping

Why Does My Air Conditioner’s Circuit Breaker Keep Tripping?

Have you had an issue with your air conditioner lately where the circuit breaker at the main panel keeps tripping?  Have you gone over to the side of the house and tried to flip that breaker back on only to have it flip right back off?  In this blog, I’ll go over what could be going wrong with your AC system when this happens.

It’s not fun to come home and realize that your house, which should be a cool 75 degrees right now, is sitting at a balmy 85 degrees.  So, you go over to the side of your house and open the main electrical panel.  There you find the air conditioner circuit breaker tripped.  This means no high voltage power is getting to your AC to let it run.  Not cool.

You flip the breaker back to the on position only to have it trip again either immediately or after a few minutes or even seconds.  Now what?  So you call your local AC guy.  He comes out the next day.  Now that the system has been sitting idle for several hours, it doesn’t surprise me when the technician who comes over for a $ 100-weekend service call flips the switch on the breaker, and the system starts working again.  Hey! Someone’s got the magic touch!

You pay the smart technician the diagnostic fee, and they head out to their next call.  Meanwhile, after 30 minutes of the system running fine, the breaker trips again.  The technician is long gone, and likely can’t be back to fix it until Monday when they re-open.

How Do You Know What’s Going on with the Circuit Breaker?

If the breaker repeatedly trips after a while, there’s a problem with one of the parts inside the AC.  If the breaker trips immediately after turning it back on, there something going in the wiring.

You can’t just flip the breaker back on and hope it stays that way.  It might! But most likely, there is a reason it tripped, and that problem will come back around.  When this comes up with my technicians at Fox Family, I tell them to slow down and ask themselves, WHY did the breaker trip?  Sure, the breaker reset when you flipped it back on, but a technician finds out why it tripped.

Danger!

I want to reiterate that I’m only giving homeowners and technicians some reasons why the breaker may be tripping.  Working with high voltage can cause severe injury and even death to even the most experienced technicians.  I read about it all the time in the mechanical chat groups I’m in.

Why Do Breakers Trip?

A breaker trips when there is too much power consumption or current at any given time.  The wire from the AC to the panel heats up enough that it trips.  This stops a potentially hazardous situation from happening.  Here are some reasons your AC will cause circuit breaker tripping:

  1. The breaker could be bad
  2. The compressor or fan is drawing too many amps
  3. A short circuit
  4. Refrigerant pressure issues

The Breaker Could Be Bad

This doesn’t happen a lot.  Breakers are sturdy switches that, when heated up enough that they’re repeatedly tripping, can become weaker and trip more easily.  A new breaker can fix this problem.

The Compressor or Fan is Tripping the Circuit Breaker By Drawing Too Many Amps

Although I can’t cover every situation that might happen, I can give you a couple of common scenarios.  If a motor gets stuck and can’t turn over when the proper voltage is applied, the motor will pull a higher number of amps.  So much so that the heat builds up in the wiring and trips the breaker.  This won’t trip the breaker immediately.  But after a while (and there is no specified amount of time), the breaker can trip whenever the thermostat is calling for the AC to be on.

At the start of the cooling season, this pattern often happens with the compressor, that black cylinder at the bottom of your outdoor unit.  It pumps the refrigerant back and forth through the copper lines, much like the heart does in the body.

Assuming the capacitor is good, sometimes adding a hard-start capacitor to the circuit will help give it that boost needed to turn the motor over.  If it does, count your blessings and start saving up for a new compressor or AC unit altogether.  It’s running on borrowed time. It’s just a matter of time before your AC gives out.

A Short Circuit

Another reason for a circuit breaker to trip is because of an electrical short.  When two normally sheathed wires like a hot wire and a neutral wire touch each other when voltage is applied, it causes a major event.

The AC uses 240 volts.  This means the two or three wires leading to your motor carry at least 120 volts.  A third one can carry even more.  If two bare wires touch each other when the system is supposed to be on, a high current situation can occur, causing the breaker to trip.  As soon as the voltage is applied, the breaker will trip immediately.

Touching Wires

Another way the breaker will trip immediately is if one of the motor’s wires touch the inside wall of the compressor.  Remember, these motors have windings inside of them that help spin the motor shaft.  The windings are covered with sheathing to protect the wiring.  But it still happens, especially on older systems that have been running for ten to 20 years or longer.

Check below for a link to my video that talks about how to diagnose a bad compressor.

Refrigerant Pressure Issues

One last reason a compressor could trip the AC breaker is refrigerant pressure.  If the pressure is too high in the system, meaning there is too much refrigerant, the compressor is once again having to strain too hard to do its work.  The breaker won’t trip immediately, but over time.

This scenario doesn’t happen as often as the other events above but can look like a bad compressor. Removing a pound of refrigerant will tell you if it’s a pressure issue because you’ll see both sides of your gauges go down a little.  If this happens and the temperature split stays between 18 and 22 degrees, I would try removing refrigerant until you get the compressor amps to get back down to below the RLA, and the temp split stays within range.

Starting Over

If removing the refrigerant isn’t working as well as you’d like, it might be smart to tell the customer you’d like to remove all the refrigerant and start over with virgin refrigerant and a factory charge.  You don’t know this system’s history, and you’re not expected to, especially if the homeowner doesn’t know it or have invoices showing what previous techs have done to repair the AC in the past. It’s a fair solution for both of you.  If you do this and the compressor is still pulling high amps, and you’ve checked everything else on the system, you have a bad compressor.

Summary

These are just a few reasons why the circuit breaker in your home could trip the breaker in the main electrical panel.  If it trips immediately after turning it back on, you likely have a problem in the wiring.  If your breaker trips after a certain amount of time, something is going on with a part in the AC system.

Let a Professional Do the Fixing

I can’t tell you anybody can fix these problems by themselves.  In fact, you might not even be able to order the parts you need as it takes a licensed contractor to purchase them from a local distributor.  Let a professional come out and diagnose the exact problem and then fix the system so you can have peace of mind.

Thanks so much for stopping by and we’ll see you next time.

Don’t miss my videos about or related to this topic:

11 Ways to Avoid Hot and Cold Spots in Your Home

Avoid Hot & Cold Spots

Delivering the right amount of air to each room at the same time is key to being comfortable.  And not just in one or two rooms.  A properly set up HVAC system will comfort your whole home or business simultaneously.

Of course, the goal is to have the same even temperatures throughout each room so when you walk through your house, you don’t feel warmer in one room than another.  Today at Fox Family Heating and Air, we’re taking a look at 11 ways to avoid hot and cold spots in your Sacramento Valley home or business.

1. Is your system sized correctly?

First and foremost, is your system sized correctly?  This means the original installer of the system did a proper load calculation of your home.  If they didn’t, then it’s not pushing enough air to your rooms regardless of whether the rest of our checklist is perfect.

2. Return air and supply air unity

Having the right amount of return air to supply air unity means you’ll be delivering the same amount of air out of your system as you are bringing to the system.  You have a return air grille or stand where your filter goes.  That’s where the system draws its air in.  On the other side of that air handler, the system supplies your conditioned air.  Systems are designed to supply about 400 to 500 cfms of air per ton.  But if your system is breathing in enough air from the return, how is it going to supply enough air to keep your home evenly comforted?

3. Adding returns will mix hot and cold air

This brings me to the option of adding more returns to strategic rooms around your house.  That return air grille in the main hallway doesn’t have to be the only return in the home or office.  For example, master bedrooms in newer homes have a return air grille installed in them.  This mixes the air in the room so warm air in the summer gets removed from the room, while colder supply air is being delivered into the room.  You’ll really notice a difference by adding a return to these pesky rooms that are warmer or cooler than others, depending on the season.

4. Closing air registers will force hot and cold air elsewhere

Not one of my favorites, but some folks will start closing down their adjustable supply registers in various room that get too much air.  They’re hoping to force the air somewhere else in the house that isn’t getting enough air.  The only thing I don’t like about this is that those registers that you start shutting down can do a couple things.  One is really annoying and the other can actually shorten the lifespan of the system.  Closing down “strategic” registers in the home or office can make those registers start whizzing.  This makes it louder in that room because we are creating a restriction that speeds up the airflow as it leaves the supply register.

The other reason has to do with the static pressure of the system.  Much like blood flow in the body, we wouldn’t want to pinch a blood vessel in hopes to deliver more blood elsewhere right, this could cause big problems with the body.  The same goes for aerodynamics in your ductwork.

5. Change those filters to eliminate hot and cold spots

Changing your filters quarterly will not only help keep your system clean, but it will allow airflow into the system.  If the filter gets too dirty, you’re creating a restriction if the system can’t breathe in properly, it won’t be able to breathe out the appropriate amount of air.  It’s like breathing in through a straw and exhaling out of your open mouth.  Eventually you’re going to hyperventilate.  So, let’s keep those passages open so the HVAC system can eliminate hot and cold spots in your home or office.

6. Keep Heat at Bay with Window Coverings

The sun’s radiant energy can warm up a room quickly.  A room with sun-drenched walls or windows allow this heat into those rooms and will warm up more quickly.  Installing window coverings will keep this radiant heat at bay.  These come in the form of screens or tinting that can be attached to the outside of windows, or curtains and blinds affixed to the inside of the windows.  Either way you choose, you’re going to enjoy having a more comfortable room if you can reduce the chance of that heat coming in this way.

7. Electronics in Rooms will Increase Warmth

It’s so popular now to have gaming systems or high-tech computer systems in a room or office.  The heat these devices put out is enough to warm up a room, making it less comfortable than other rooms in your house.  Adding more supply air by using a larger duct will help to deliver more air to that room.  Just like I mentioned above, a better solution may be adding a return to this room as it will remove the warm air while cold air is being supplied to the room.  This will make your room more comfortable, faster.

8. Ceiling Fans will Mix Hot and Cold Air

Another way to mix the air in your room is to turn on that ceiling fan.  When it’s hot outside, have the fan blowing straight down towards the floor.  The warmer it is, the higher the fan speed should be.  Conversely, in the wintertime, turn the fan so it blows upwards.  Both ways will mix the air more effectively and make those rooms more evenly comforted.

9. Keep Hot and Cold Air Moving by Preventing Airflow Restrictions

Remove hot and cold air spots by taking a look at your ductwork.  It might be under the house or in the attic.  If you can see your ductwork, you will be able to determine if it’s delivering the air efficiently.  If the ductwork is sagging or kinked, it won’t deliver the air properly.  Each duct has a finite amount of air it can deliver appropriately.  Making sure it is installed correctly is a great way to keep your house evenly conditioned.

10. Prevent Hot and Cold Spots by Checking Insulation Levels

You can also control hot and cold spots by paying attention to insulation.  Attic insulations levels can greatly impact how quickly that hot or cold air infiltrates through the ceiling into your room.  Sometimes various service professionals will need to work up there.  In the process, they may matte down some of your insulation, making it less effective.  If there is not enough insulation over one room or the other, this will create hot or cold spots.  These reduce your comfort level in those rooms.  By blowing in some more insulation, you can make your whole house more comfortable to be in.

11. Properly Sized Ductwork Improves HVAC Efficiency

The size of your HVAC system as well as the right size duct system to deliver that air evenly are both crucial to your comfort.  This isn’t the easiest thing to figure for most DIY’ers.  An hvac professional can help you determine what size duct is needed for each room.  A system of supply and return ducts running every which way can be confusing.  Making the right decisions with your ductwork will make your HVAC system more efficient and comfortable for your home.  This will eliminate hot and cold spots in your home

Summary

Let Fox Family come out and take a look at what can be done to make your home more comfortable if you’re experiencing hot or cold spots.  Making your system as efficient and effective as possible will certainly add to your quality of life.

Thanks so much for stopping by, and we’ll see you on the next blog post!

Don’t miss our videos on related topics:

How I Add Refrigerant to a Central Air Conditioner

How I add refrigerant

Hey HVAC techs! I’m Greg Fox, and today we’re going to talk about adding more refrigerant to an air conditioner.  I wanted to expand on our recent AC troubleshooting series by going into each part of its sequence of operations.  This week, it’s the refrigerant.

Now, I’m not going to get into the legalities and moral issues here of refilling refrigerant on a system that is leaking, but you should know a few things:

  • Refrigerant is expensive for the customer – If you have to keep refilling their refrigerant, which we do not know how often that will be, it can add up quickly.
  • They know their air conditioner better than us.  If we’ve never been to their home to refill their refrigerant before, there’s no reference for knowing how BIG their refrigerant leak is or WHERE the leak is.
  • The customer could lose all of their refrigerant tomorrow if they have a significant leak… or if it is a small leak, the refrigerant could last them all year or longer.   

Let’s go over some basics to charging an air conditioner on your average 90-degree day in the middle of summer.  Upon arrival at the house, your customer tells you the air conditioner worked just fine last year, but this year the system seems to run non-stop, especially as the summer days get hotter and hotter.  You ask the customer, “Have any other technicians been out to make repairs on your system since last year?” It’s very likely the customer will say no.  

There’s a lot of things that can affect the refrigerant charge.  Just remember, for the sake of time, we’re keeping this dialogue short, so we can get to the point of charging the system up.  

I like what Bryan Orr mentioned in an article I read.  He said,

“We need to set up equipment so that it won’t freeze during normal operating conditions.   At the very least, the typical residential A/C system should be set up so that the return air temp can get all the way down to 68° and still be just above freezing at the evaporator coil.

Let’s say it’s 78° in a house on an R410a system, and your suction pressure is 108 PSI.  That means your suction saturation (coil temperature) is 35°… so the coil won’t freeze.

However, the coil temperature will drop approximately 1° for every degree the return temperature drops. 

Remember, at 78° inside, the evap coil was at 35°, So if the customer sets it down to 74°, the saturation would get down to 31°, and the will start to freeze.

Knowing this, let’s grab your temperature probe and check the return air and the supply air.  Here you notice the difference between the two is about 8 degrees.  As a tech, you know the split should be around 18 to 22 degrees.  

Next, you head outside and feel the suction line to see if it’s cold. Now, there is some validity to the old term, “beer can cold” but it should not be the measure you go by to check the refrigerant charge. It can, however, give you a clue as to the condition of the system.  In this case, the suction line at the AC is barely cold.  Now, I’m not always a huge proponent of hooking my gauges up to a system every time I go out to diagnose a system, but in this case, we can tell something’s not right with the cooling system, so in this case, I want to see what is going on inside of it.

Hook your hoses up to the liquid and suction lines.  Be careful of blowback so you don’t freeze your hands.  Follow all safety precautions. 

Now, what do you see on your suction side?  I like my techs to talk to me about the evaporator coil’s TEMPERATURE and the TEMPERATURE of the condenser coil.  When I’m on the phone trying to help a tech out in the field, it’s hard for me to remember all the pressure-temperature ratios between the different refrigerants we use. 

So if someone tells me the evaporator coil is 40 degrees, I can immediately tell the coil is not freezing.  If someone tells me the temperature of the condenser coil is 140 degrees, I can immediately translate that to an outdoor coil that is under some seriously high pressure.

On the refrigerant gauge, the outer circle and those numbers are the pressures.  The inner rings of numbers reflect the temperature.  This is how I want my techs to communicate pressures to each other. It’s more efficient this way.  Most gauges these days have a green ring for R22 and a pink ring for R410.  The pink ring’s numbers are what we are using for evap and condenser coil temperatures on a 410 system.

Here we see that the evaporator coil is at about 20° F.  For proper refrigerant levels, the image I want you to project in your mind is this.  Our end-goal here is to have liquid refrigerant reach all the way to the TXV at the evaporator coil to meter the refrigerant appropriately.  Right now, there’s not enough liquid in the system to do that.  This means vapor is making its way to the metering device, and we’re not giving the coil enough refrigerant to interact with the speed of the blower air moving across it.

We need the perfect balance of airflow and refrigerant pressures to create that 18 to 22-degree temperature split we are looking for.

Let’s suppose this system holds 10lbs or R-410a.  In my mind, I’m thinking the system is about halfway charged. It’s an approximation, but we have to let the customer know about how many pounds we want to add, so they give you the okay to move forward.  Of course, you don’t know for sure, but they should be aware it could be around 5 lbs, and that will cost (whatever, $100 a pound). We need to let them know it could be a couple of pounds more or a couple of pounds less, but either way, we need permission to move forward.

Using a scale is the only way we can know for sure how many pounds of refrigerant we are adding. And it’s cool to let the customer know you’ll be using this too. It’s reassuring to them. This is great for preventing you from overcharging the system too.

My service hoses are already hooked up.  I’m going to start by putting my charging hose on the tank of refrigerant.  Next, I open the refrigerant tank valve and place it upside down on the scale. With the gauges closed on the manifold, I crack open the connection where the charging hose meets the manifold.  Not too much, though.  We just want the refrigerant to prime itself up to that point so we get rid of excess moisture and air in the hoses.

Reset the scale back to zero, so we know how much we are adding as the refrigerant enters the system.

I recommend you put an amp clamp on one of the wires leading to the compressor.  If you’ve seen my video on diagnosing a bad compressor, you know that the compressor’s amp draw correlates with the refrigerant pressures inside the system.  The healthiest compressors will run at around 60 percent of their RLA.  When you’re charging up the system, you’ll see the amp draws fluctuate as the refrigerant goes in and settles down.  Use your knowledge about the compressor amp draws to monitor your charging process.

Okay! We’re ready to charge!  With the charging hose valve open, we’ll start opening the suction side valve.  A quarter to half of a turn is enough.  There is no approximate amount of time it’ll take to insert 1 lb. of refrigerant.  Each situation is different.  To know for sure, use your scale.  

In this situation where we think the system is about 4 or 5 lbs low, let about 2 lbs flow into the system and wait for 5 to 10 minutes for the system to equalize.  Question.  How long does it take for the refrigerant to cycle through a typical residential split system? I’d say about 3 or 4 minutes.  If you have a different answer, let me know in the comments.

So we see now the low side has come up to about 27 degrees or 92 psi.  Our evaporator coil is still freezing.  Let’s add two more pounds and wait.  I know there’s a lot of pressure on techs to get their calls done quickly so they can get to the next one, but it’s essential to let the system stabilize before adding more refrigerant.  If you add too much, too soon, you could see the pressures skyrocket insanely fast.  And now you have to recover some refrigerant into a separate tank which takes even more time!

Now we are getting close to 32 degrees or about 100 psi on the suction side.  From here, we want to start dialing our subcool to whatever it is the manufacturer recommends.  This system says 10 degrees subcooling on a 95-degree day.  Let’s get a temperature probe on the liquid line and start getting our reading from it. We’re going to be subtracting the high side’s temperature and the liquid line’s temperature to come up with our subcooling.  

Add refrigerant a little at a time until the difference between those two numbers is 10 degrees. There’s nothing tricky about this.  Just don’t add too much too fast.  Add refrigerant and wait for the numbers to stabilize. 

You’re going to be looking for the low side pressure to be around 40 to 42 degrees or 125 psi.  The high side pressure/temperature will likely settle around 15 degrees above the outdoor temperature.  So on a 90-degree day, you may end up with a high side temperature around 105 degrees.  If you can get your numbers around this area, you’re close!  But let’s really get it dialed in.  Get that subcool to 10, plus or minus 2 degrees.

I will tell you; it takes longer to move the needle on your gauges when there’s less refrigerant in the system.  As the system starts getting close to the proper subcool, you’ll want to finesse the time you keep the manifold open, allowing refrigerant into the system.  Overcharging can happen quickly, especially on a hot day.  

Getting close to your 10 degrees subcool?  Cool!

Once you get it to this point, check your temperature split inside.  Is it around 18 to 22 degrees?  Great! You’ll notice the liquid line is a little bit warmer than the outdoor temperature.  Also, the suction line will be damn near “beer can cold!”

Test the system while it’s running.  Get your amp draws on the condenser fan motor and compressor.  Cycle the system on and off at the thermostat to make sure the system is operating correctly.  If it is, you’re good to go.

Well, I hope this has helped you when it comes to the charging process.  I make my videos for my technicians to reference when they are in a bind out in the field.  But if this can help anyone else, that’s great.

Thanks so much for reading, and we’ll see you on the next blog.

https://youtu.be/plTCLJF_zQk
 
 

Do I Need an AC Tune-Up or a Diagnostic Service Call?

how to handle a refrigerant leak at my home

Our administrative staff has gotten very good at being intuitive about what a potential customer really needs from a Fox Family Heating and Air Conditioning service technician.  With all that fancy HVAC jargon like AC tune-up, diagnostic service call, HVAC inspection, or safety inspection, how are you supposed to know what it is that you should be asking for when you call in?

In this blog post we’re going to narrow it down to our most needed services.  Let’s talk about how to tell if you need an AC tune-up or a diagnostic service call.

Intro

I’m really not trying to bag on anyone here, but it’s true that some people will call in to Fox Family and say they need us to come out and do a tune-up on their system.  So, we’ll ask them something like, “Is your system currently working okay?”  or, “Are you having any problems with your system right now?” and they’ll say, “Yeah, but I notice a burnt smell coming from the registers and not as much air seems to be coming out.” Or, “Yeah, but it’s not as cool in here as it used to be, so I just thought you could come out and add some freon.”

Tune-Up Service Calls

So, here’s a chance for me to clarify the difference between a diagnostic service call and an AC tune-up. What we’re trying to  identify when you call in to Fox Family is whether your AC is running just fine or if you think something just isn’t right.  Folks who call us for a tune-up think their system is running just fine.  But they just believe getting preventive maintenance will make their system run cleaner and last longer.

When we come out on a tune-up, we have a checklist of things we are looking at.  The main components of the system — your thermostat, your filters, and the ductwork.  We’re also checking things like the temperature of the air coming out of the registers in your rooms versus the temperature of the air going into where your filter is in the hallway.  Then we start really looking into the major motors and devices in the system that make your machine work.  With our meters and other testing equipment, we can see what’s going on inside the motor.  Is it working too hard, and is the right voltage being applied to it?  Is there enough refrigerant in the system?

On top of the mechanical components of the system we look at the drainage system, refrigerant metering devices, and high voltage wiring and tighten connections as needed.  We can also check for shrubs around the AC that might prevent proper heat transfer, make sure the unit is level, and of course clean the AC as well.  Your utility company and Fox Family thinks a clean air conditioner will last longer than a dirty one.

Diagnostic Service Call

You might also call us if your system isn’t running quite the way you think it should be.  Meaning the Friday before you went camping for the weekend, the AC was working just fine.  But now the air coming out doesn’t seem to be as cold.  This means you’re calling for a diagnostic service call.  Some people just call it a service call.

Here, your technician will ask you a few questions about your system and go straight for the problem so you can begin cooling as soon as possible.  They won’t really be interested in combing over the entire system with a fine brush.  But they will make sure the rest of your AC is functioning properly, so you won’t have any foreseeable problems.  Having said that, you technician is probably not going to replace your capacitor in the outdoor unit and discover that your drain line isn’t functioning properly since you didn’t give us any reason to check on it’s performance.

Another example would be something like discovering your compressor was bad but two weeks later your control board goes out because of a fractured solder connection.  That’s something we’d likely see and tell you about on a furnace tune-up in the winter but not really look for when we are just trying to get your system cooling again on a 100-degree day.

I know there are some weird nuances I’m talking about here, but hopefully I’m making sense.  On tune-ups, we are looking for anything that’s running well as well as what’s running poorly or could potentially break down soon. We’re also there to clear the condensate drainpipes and clean the system.

The Goal of a Diagnostic Service Call

Getting you back up and running as soon as possible is the main goal on a Fox Family diagnostic service call.  Technicians will typically look around the unit they are working on.  For example, if the AC outside has a capacitor fail and you thought the system was working just fine until yesterday when you called us, they’ll likely just change the capacitor and maybe even forego climbing in the attic to do a thorough analysis of anything that might be going wrong with it.

We’re damned if we do and damned if we don’t sometimes.  Some folks want to pay as little as possible to get their system back up and running, and almost find it offensive if we recommend other repairs.  These repairs might not actually prevent the system from running today, but could go out soon.  Others say, “Well, why didn’t you bring that up last time you were here two months ago?”

Providing Sound Advice on a Service Call

All in all, I think technicians are just trying to do right by their customer.  But you do need to beware of some companies that pay their technicians primarily based off what they sell.  Some of these technicians don’t care about being practical with you or your money.  This is called “performance-based pay.”  They’re going to bring up every possible flaw with your system and perhaps try to sell you things you don’t need.  If they don’t, they can’t put food on the table for their family.

The company doesn’t pay them unless they sell something to you.  I personally don’t believe in this philosophy practiced by some of the HVAC companies around the Sacramento area.  They’re the companies giving the HVAC industry a bad name around here.  They have greedy company owners and highly sales-oriented technicians motivated only by money.

We pay our techs a good salary with some commissions here and there.  We count on them to treat our customers with practical, sound advice for their AC system.  This creates a good relationship with our customers for the long run, and an honest company to do business with.

Service Call Pricing

Whether you need a simple tune-up or a diagnostic service call, it’s going to be the same price at Fox Family.  So there’s no better call to have us come out on.  Knowing the difference means you’re better prepared.  You can make the phone call to your HVAC company and tell them exactly which service you need.

A tune-up won’t correct a broken system, much like a tune-up or oil change on a car isn’t going to fix your transmission problem.  Tune-ups may identify some issues with your system that you didn’t know existed.  But a diagnostic service call may identify the need for regular preventive maintenance in the form of a tune-up.

Thanks so much for stopping by and we’ll see you at the next blog post!

When Should a Technician Recommend a Leak Search on my HVAC System?

how does an hvac unit work

Every spring and early summer we get what’s called the “first wave” of worried homeowners and rental tenants who realize there is something wrong with their AC system. Sometimes it’s a mechanical part like a capacitor or a motor, but other times it’s a refrigerant issue. This week we’re going to talk about refrigerant leaks, what the laws are and moral obligations you and your technician may have when it comes to refilling your HVAC system with refrigerant year after year.

As a technician who goes to hundreds of homes every summer in the hot Sacramento valley, I go out on these calls all time. Sometimes customers will call into the office and tell us another company told them they have to get a new system because they’re not allowed to fix older systems anymore. Other excuses I hear is, they don’t make R-22 anymore so there is no refrigerant to add back into their system. Unsuspecting homeowners will believe these technicians and fall for their unethical tactics. Other homeowners will call Fox Family Heating, Air Conditioning and Solar where we will offer a free second opinion to come out and verify a leak that supposedly exists and give them proper solutions to remedy the leaky system.
Let’s talk about the obligations we as decent human beings have to this great planet we live on. The government regulates and monitors our usage and consumption of refrigerant in this country. In other parts of the world, not so much! It’s crazy to think of the irresponsibility technicians in other parts of the world have when it comes to just pouring pounds and pounds of damaging refrigerant to earth’s ozone layer. You see, the refrigerant in our older systems now is R-22, a mix of chemicals that contains chlorine which degrades the ozone layer quickly if it were to get out into the open. The systems in our homes hold anywhere from 3 to 20 lbs. of refrigerant. Just two lbs. of refrigerant leaking into the atmosphere causes as much environmental damage as a van driving 10,000 miles down the road. The damaging result is global warming and accelerated environmental weather extremes.

You know the stories. You’ve seen it on TV. Al Gore told you this crazy weather is because of an accumulation of damaging practices we have as humans to this giant world. Refrigerant loss from our home HVAC systems don’t even have a definite requirement yet as to when we HAVE to perform a repair on the leak. The government right now, just says if the system holds over 50 lbs of refrigerant, then we have to fix the leak. Not only do we have to fix the leak on those systems but we have to come back and verify that leak is taken care of bi-annually until the EPA requirements for follow-up are satisfied. We as technicians are now responsible for logging any refrigerant coming in and out of any given system, not just commercial and industrial machines, but residential too.

how does an hvac unit work
When I get out on these calls with low refrigerant suspected, I will attach my gauges to the air conditioner outside and fire it up. The system will start but doesn’t sound normal. A light clanking noise quickly repeating itself in its own rhythm. After a few minutes of running, the gauges show me there is indeed very little refrigerant left in the system.

What does this mean? The HVAC system is separated into three lines for your refrigerant to stay in. The evaporator coil at your furnace, the condenser coil on the outside unit, and the copper line set that runs between the two coils. When the system was installed, these three sections were brazed together by the technician out at your house.

During the call, and at the very least, a technician should volunteer to visually go around and check all the brazed points in your lines. There are at least two points at the evaporator coil and two at the outdoor condenser coil that the installing technicians brazed together to complete your HVAC system’s refrigerant lines. The technician should be looking for oil around these connections. Why? Because the refrigerant in the system carries oil with it to lubricate the components inside the system, like the compressor. This means if the furnace and evaporator coil are up in the attic, the technician needs to get their ladder out and go up there to do this visual check. While they are up there, they should check the P-trap for oil in the condensate lines. A good technician knows that the majority of leaks happen at the evaporator coil or the condenser coil and very rarely at the line set that runs in between the two. If the evaporator coil is leaking badly enough, oil will drop down into the evaporator coil drain pan that the water usually goes down into. It then starts its way down the condensate drain line until the oil fills up in the P-trap. These are very easy checks the technician should include on the original diagnosis charge.

If they don’t see anything there and are sure they have checked all the easier points of access to the refrigerant lines at the evaporator coil, the tech should check the outdoor coil looking inside the top off the unit and all around it looking for darker stains of oil. Also, are the schrader cores where the gauges attach too loose or not sitting correctly within the service valve? If the tech is satisfied the leaks are not there, then he/she should start an investigation of sorts.

“Is there a history of leaking with this system?” is a question the technician should ask. The homeowner has some obligation to tell the truth here. If the owner deceives the tech, then we’re really not getting anywhere are we? I can say there have been very few owners that I didn’t believe when they told me, “No, never any leaks before,” or “Well we just moved in here two months ago.” At this point RIGHT HERE a technician should offer a strategy to the homeowner to help determine if it’s a leak and if so what will we do to try to find the hole and repair the system so it doesn’t leak anymore.
Our technicians at Fox Family ask if there is a history of leaking for this HVAC system because it helps us establish a base point for the rate in which this system is leaking. We want to know if there has been refrigerant added to this system before, and if so, when?

The main reason why I wrote this blog. If this is the first time the system has been “topped-off” to get you cooling again, then we should get you cooling and use this as a starting point to determine if this system is leaking and if so, how much and how often?

If the refrigerant was admittedly, “topped-off” last year, then I think it is a good time to introduce the idea of looking for the leak. This is mentioned whole heartedly in the best interest of the planet and its survival. We want to avoid being unethical here now that we know the system is being topped off every so often to maintain it’s cool air. R-22 has chlorine and R410 still has massive global warming potential. We need to stop that from getting out to the ozone! If we can find the leak then we can get the system back to factory specs.

When I want to introduce the leak search, I tell my customer, let’s get you back cooling today so your family is comfortable. The we should go ahead and start the leak search process which includes us going to the different parts of the AC system with our electronic sniffer looking for the leak. The majority of the time I can find the leak with this method. That cost $X amount and is good for the first hour of searching for the leak. If we can’t find the leak after the first hour, we bump it up a level to $X amount. This level of leak search includes us adding a fluorescent dye to the system so we can let it circulate in the system for a couple of weeks (while you are still staying cool). Then we come back out and look for the dye. If there is indeed a hole somewhere in that copper or aluminum line, the oil and the dye inside the lines will spew out of the hole and splash onto anything around it like the aluminum fins on the coil or the condensate drain pan and into the P-trap. We’ll take the dye kit which comes with some yellow glasses and a UV flashlight. When we shine the light onto the dye which has come out of the leak and we have our yellow glasses on we can plainly see the leak is coming from there. We shouldn’t stop looking though! Just because there is one leak doesn’t mean there aren’t two or more holes.

If the leak is in the fins of the evaporator or condenser coil, we can’t get in there to fix the leak without compromising the standards of the manufacturer. It’s possible yes but, the possibility of the repair causing a restriction or other repair if the brazing compound didn’t settle properly on the under side of the repair spot. Also, the copper or aluminum is a lot thinner on the coils than the copper line set that runs in between. This means when the leak is in the evaporator or condenser coil, and it’s not on a u-bend or other easily accessible spot, we’ll recommend you getting another coil from the manufacturer. We’ll get it ordered and replaced for you in no time.

No matter where the leak is, the money you have paid for the leak search will go toward the cost of repair. Some of these repairs can be upwards of $2000 to replace parts, so it’s nice to know we can find the leak, and then put that money towards the cost of repair.

Our clients always appreciate knowing exactly what to expect during the leak search process. Simply explaining the repair in common terms that aren’t too “techie” for the customer are also appreciated. A leak search is not always needed just because you went out to a house for the first time and it has a leak. There is proper way of establishing knowledge and data about this particular unit. Starting at that first time out there and getting the customer cool is the most important thing. Next year if we have to add refrigerant again, then we should establish a plan for finding the leak. It’s our moral obligation as techs and as homeowners to find the leak and repair it. If there is a history of leaking refrigerant from your system, it’s on you as homeowners to let us know. I realize it’s going to cost some money to make the repair, but once it’s fixed, you won’t have to keep paying for refrigerant that just keeps getting more and more expensive every year.

Thanks for checking out this blog on leak search recommendations. If you are a homeowner and are concerned that what the other technician said doesn’t match I’m saying here, you might want to call a trusted HVAC company that will set you straight and actually give you options other than “You need to replace your system!”

How Long Can I Wait to Have My HVAC System Repaired?

Keep Your AC Running the Rest of the Summer

Today on the VLOG (Video Blog) I talk about what happens when you make quick-fix or band-aid repairs on your HVAC system.  If your system is operational but you know it needs a repair but you just don’t want to spend the cash, what can you do?

something else to consider, if your furnace or home air conditioner is more than 8-10 years old, and you are not having regular maintenance performed on it once or twice a year, you could be in for multiple repairs in the years to come. I share the details of what is under warranty and what is not.

We appreciate you tuning in and welcome your LIKES, COMMENTs or SHARES!

A Day in The Life of an HVAC Technician: Episode 4

Should I go to HVAC School

Fox Family Heating and Air wants to show you our team and what it is they go through on a regular basis to be an HVAC company.

Check out our latest video to see a day in the life of an HVAC Technician.

In this episode, Fox Family Heating and Air takes on a house that wants to convert from an all-electric heating pump to a gas furnace. The tricky part is, it’s under the house and the furnace and coil won’t fit. Check out this episode to see how we get the job done.

Liking our Day in The Life HVAC Technician episodes? Check out the other episodes here.  Contact us for all of your Sacramento area repairs.

 

 

FAQs about Replacing HVAC Systems

FAQs about replacing HVAC systems

How long should it take to decide which system or contractor I want?

If it’s an emergency you may decide still to think about it. Some people even go as far as nursing it with one of these mobile floor AC units. But when it’s 100 plus degrees outside and 92 inside, anything helps right? Absolutely!  Let’s review some FAQs about replacing HVAC systems and what you might consider.

Seriously though, you will need to pony up at some point for the sake of your health and comfort, and your family’s health and comfort. Contractors in California are required to give you a “3-day right to cancel.” It’s a little paragraph on the contract you sign acknowledging this right. Then the equipment can start to be installed on the fourth day after you sign the contract. You can waive that “Right to Cancel” if it’s an emergency and the system needs to be replaced right away for something like an elderly person or infant’s health. Whatever it is, the State says in order to waive the right to cancel, it has to be for an urgent reason. Can you imagine coming home from the hospital with your newborn and your compressor blew on your 20-year-old AC?

Do your research before replacing an HVAC system

If it’s not really an emergency you can take your time and really file through the right type of equipment for you and which contractor you want to hire. Systems come in all ranges. From the lower grade systems to the notable and trustworthy HVAC systems. Do your research and know what you really want in a system. You’re only going to have to make this purchase once or twice in your lifetime, so it’s not something most people really think about on an average day. HVAC contractors do think about this every day, but don’t believe everything you hear from these guys because it can be smoke and mirrors. You want to know the equipment model number and maybe do some research on the equipment. You can literally type in the model number in the search bar and find great information. Search about Trane, American Standard, Ruud, Rheem, Lennox, Carrier, Goodman, York, DayNight, Bryant, Payne, etc. Every brand out there is going to say they have the best home comfort system in the world, but can they prove it. Consumer Reports Magazine still puts out ratings for each brand every year. Consistently, Trane and American Standard are the brands at the top of the list.

HVAC system costs

Equipment alone can range anywhere from $6500 to $20,000. Depending on who you buy from and which SEER rating and technology you are looking for. We offer four different levels of systems. Bronze, Silver, Gold, and Platinum. This translates to 14, 16, 18, and 20 SEER systems. Basically, for a little more money you’re getting a more efficient system. Think of it like MPG on a car. The more efficient they are on the gas mileage, the more desirable they are. The higher the SEER rating, the higher efficiency they have to operate it, translating to lower utility bills.

The technology is unbelievable right now. We are seeing equipment that can hold the temperature of your house within a ½ degree all day long no matter the temperature outside. With these high-end variable speed systems, with Wi-Fi technology for your cell phone accessibility and communicating thermostats with the furnace and AC is really just amazing right now!

Fox Family Heating and Air Systems

Most people see our four options for systems and pick something in the middle. They see 14, 16, 18, and 20 SEER systems and typically pick the 16 or 18 SEER systems. Very rarely, do I see people choosing the 14 SEER system.

If you have the opportunity and it’s not a major emergency, take your time with these kinds of purchases. Find the right contractor for you, with good warranties, good thermostats, and other safety features for the system. For instance, a condensate safety switch, a compressor start kit, and a compressor sound blanket. This is a value purchase you’re not going to want to skimp on. If you have any questions about your new HVAC system please feel free to call me, Greg Fox at Fox Family Heating and Air Conditioning. I promise to give you great value for your next HVAC project.