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!

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:

Why are my AC Registers Sweating?

Low Dew Point

During the summer of 2013, I got a service call about some supply AC registers sweating or forming condensation on them. It caught me off guard because the Sacramento Valley summertime conditions don’t usually allow for sweating ducts and registers. In this blog, let’s go over some facts, opinions, diagnoses, and solutions to sweating ducts and registers.

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A quick explanation of what causes sweat or condensation on ducts and registers:

It all comes down to the dew point of the air surrounding the surface forming condensation on it.

 Facts

Air is a gas. And that air needs to be cooled to a certain point to achieve 100% humidity. At 100% humidity, air cannot hold more moisture in the gas form, so it becomes liquid…condensation. What is the temperature of the air in that room, supply duct, or the ceiling register that 100% humidity occurs? That’s the “dew point.”

Photo posted on Energy Vanguard
Photo posted on Energy Vanguard

The National Weather Service says, “The higher the dew point
rises, the greater the amount of moisture in the air. That directly affects how
comfortable it will feel”.

 

http://www.dpcalc.org/

“Many times, relative humidity can be misleading. For example, a temperature of 30°F and a dew point of 30°F will give you a relative humidity of 100%. Still, a temperature of 80°F and a dew point of 60°F produces a relative humidity of 50%. It would feel much more “humid” on the 80-degree day with 50% relative humidity than on the 30-degree day with 100% relative humidity. That’s because of the higher dew point.”

We are more “comfortable” during the summer when the dew point is 55°F and less. At 55° to 65°F, the air in your house starts to feel “sticky” or “muggy.” And a dew point above 65°F becomes downright oppressive. The higher the dew point, the less comfortable the conditions are.

So now we can talk about your sweaty ducts and registers.

The house cools down when the air conditioning has been on for a while. But the duct that the air travels through gets cold too. The metal register that the air comes out of gets cold too. There’s even a metal box sometimes called a boot, c-box, b-box, or just a can, that connects the air duct to the metal register that the air comes out of in your room.

Water vapor loves cold metal and other surfaces because the dew point of the surrounding air allows condensation to develop on them. Like a cold glass of water does.

And the longer the air conditioner pushes cold air out of the ducts in an environment where the surrounding dew point is higher, the more sweat will form on the surface of it.

And just to add to the nuisance of condensation, water on those cold surfaces can start to grow mold and bacteria. It can also cause the paint on the metal registers to rust and chip. And if this is going on inside your ducts in the attic or basement, you may not even recognize it because you can see inside them without tearing into the duct or running a camera scope inside them.

Diagnosing

A lot of contractors and their salespeople will suggest adding more insulation to the attic. Or, they’ll say getting new ducts with thicker insulation will solve the problem. But you could add several feet of insulation, but if the outer lining of the duct is cooler than the air around it and it reaches the dew point, condensation is still going to form on the duct. So, adding insulation isn’t always the solution.

Allison Bailes at Energy Vanguard wrote a great article that asked, “How do you tell which is the culprit? Is the dew point too high or the supply vent too cold? The special number here is 55° F.  Well, it’s special if you keep your house a 75° F for the indoor temperature and 50% relative humidity. Those conditions correspond to a dew point of 55° F, our special number.”

The higher the relative humidity surrounding your problem surface (the duct or the register), “the higher the dew point is at a given temperature. That means you’re more likely to get condensation because the supply vent doesn’t have to be as cold. For example, at a temperature of 75° F and relative humidity of 60%, the dew point will be 60° F.  A supply vent at a temperature of 60° F or below will sweat in that case.”

There’s a Dew Point Calculator website that lets you play around with temperatures and humidity levels to determine the dew point. Like in my house, it’s not unusual to keep my house at 70°. And because the humidity level in my Sacramento house is usually around the 40% area, my AC registers won’t start forming water until the temperature of the metal register goes below 44 degrees…the dew point.

Solutions

The obvious solution to this is buying a ventilating dehumidifier. This helps even when the AC is not running! Whether the AC is operating or not, running a dehumidifier is great for when the AC cools the house fine but doesn’t reduce the humidity enough.

Photo courtesy of thermastor.com

Energy Recovery Ventilators (ERVs), Heat Recovery Ventilators (HRVs), and whole-house fans actually bring in humidity from the outdoors.

Running bathroom fans or laundry fans is a common thought to remove moisture from the room. Some people say these fans remove the humidity, while others say (like a whole house fan does) they bring in air from the outside, which carries humidity with it. 

Blower Fan speed – When your installer sets the blower speed on your fancy new system, they’re doing their job right. Not every installer does this. They take a temp split and call it good. But every air handler manual has specific blower settings for each ductwork and static pressure situation. 

If you have humidity issues in the house and the tech is waffling on setting the speed one dipswitch higher or lower to match the compressor speed and static pressure, always choose a little lower. While cooling the house faster, high airflow doesn’t allow the evaporator coil to collect enough condensation. A wet evaporator coil means better humidity removal.

Some other issues could be:

One duct laying on top of another can increase the potential for sweating, so separating the ducts will help. 

If you routinely keep it like a meat locker in your house, say 62°F, but the relative humidity inside your home is in the high 50s, you will start to have registers that form moisture on them because it’s very likely that your registers will get colder than 46°F which is the dew point at that time

Remember, air conditioning systems usually blow air out of your registers 18 to 22 degrees colder than the air going in. Of course, keeping the house at 62° can cause more issues than that. Evaporator coil freezing is very likely at that point too. And then you start to have mechanical problems that gets really expensive.

Manual Zr says supply air should not drop below 45 degrees for compressor reliability but also influences duct condensation. Besides setting your thermostat too low, other reasons for low supply air temperature are dirty filters, dirty coils, closed registers, kinks in the ductwork, restricted ducting with high static pressure, and improper airflow commissioning where the installer didn’t set the blower to the right speed.

Even the way the duct is attached to the boot/c-box can influence the air stream as it leaves the registers. A duct that heads straight into the boot will likely flow evenly through all the vanes of the registers. But a duct that kinks in sideways or doesn’t have an (insulated) hard 90-degree elbow to direct the air stream properly can cause eddies making that particular part of the boot colder than other edges of it. 

Negative pressures within these eddies can even pull warmer room air into the can, intensifying the potential of forming that condensation. That’s why this can happen in more humid rooms of the house like bathrooms and laundry rooms.

When you have registers or the cans they’re attached to, sweating, you have to start eliminating air leaks:

Tape and seal the c-boxes to the sheetrock (or wood flooring if the registers are on the ground.)  The ducts that take off from the plenum at the furnace should be sealed around the start collar. There’s duct sealant that is great for that.

CCWI-181There are a couple of trains of thought here, but I agree with this one. Adding more insulation around the outside of the can with blown-in insulation may not fix the problem. You can still end up with the ideal temperatures for the can to get colder than the surrounding air because there’s no vapor barrier on top of the added insulation. However, if you were to use closed cell spray foam, you would have the insulation and the vapor barrier needed.

The reason behind this is, again, trying to keep the boot or register from getting colder than the dew point surrounding the metal.

Another way to prevent AC registers sweating or from condensation from forming on the registers and ducts is by insulating the inside of the can. This way, you’re keeping the metal of the can from getting too cold.

I’m hoping this helps with your question about why ducts and supply registers in the home form condensation on them. It all comes down to the dew point of the air surrounding the surface, forming the moisture.

References used:

National Weather Service quote https://www.weather.gov/arx/why_dewpoint_vs_humidity

Allison Bailes https://www.energyvanguard.com/blog/why-do-air-conditioning-vents-sweat/

Air Duct Photo posted on Energy Vanguard
Air Duct Photo posted on Energy Vanguard
Dew Point Calculator

That’s Not How Zoning Works!

how zoning works

How Heating and Air Zoning is Supposed to be Used

I find that some technicians don’t know how to explain to their customers how to properly use their zoned heating and air conditioning system. They tell their customers to just set the temperature to 75 on both floors and leave it. That’s not how zoning works! If you wanted to have both floors or both zones at 75 degrees, why not just cool the whole house at once? Why do we even need zoning at that point? On today’s blog we’re talking about the do’s and don’ts of zoning.

Heating and air zoned houses, or houses with two or more thermostats, are usually found in homes that have two floors, or in sprawling ranch style homes. In this blog we’re going to talk about older homes that have had zoning added to their now oversized system. We’ll also talk about what kind of lifestyle fits best with a zoned system. And finally, we’ll be discussing how to use zoning to save you money, which is really why zoning in a home is even a thing.

Many homes in the Sacramento area are big enough to support families of 2 to 6 people. Such a home will have a designated living area that includes the kitchen, dining, family rooms, common area restrooms, entryway and other common areas. The other part of the house consists of the master bedroom, master bathroom, larger closets, the kids’ bedrooms, their bathrooms and sink areas, and the laundry room. You could easily break this home down into two “zones” with a thermostat to control each one.

The System is Oversized

To illustrate my point, let’s just say you have a typical 1950 sq. ft. home of conditioned space. This doesn’t include areas of the house like the closets, pantry, and other rooms that don’t have registers supplying air to them. This hypothetical house is two stories and originally came with a big 4-ton air conditioner that would satisfy the whole house at one time.

Ten years later, the owner adds a thermostat to the upstairs area, so they’ll have two zones; one for upstairs, one for downstairs. Another 10 years goes by and the system is now 20 years old.  Because it no longer cools as it should, the new owner is ready for a new system.  He doesn’t understand why he’s being told the new system should be smaller — much smaller! Because that’s not how to use zoning.

Heating and air zoning is an excellent idea!  But keeping that big, old 4-ton system there is a big mistake. If a 1950 sq. ft. home is divided into fairly similar sizes — 1150 sq. ft. downstairs and 800 sq. ft. upstairs, for example — then only one zone is calling for cooling.  That big 4-ton system (which remember, was designed to cool the whole house at one time) is overwhelming the temperature change in that one zone.  That’s half of the house!  It’s over pressurizing the ducts for that zone.  It’s sending a high velocity of air through the registers of that one zone. This is generally putting a big strain on the entire system, with the exception of the unused zone.

High Blood-Pressure Isn’t Good, Right?

This strain is similar to high blood pressure for the human body. You can run on high blood pressure for a while, but if it’s not regulated, the body can suffer and fail earlier than usual. The same goes for the compressor which is a lot like the heart of the human body. It pumps refrigerant to and from the indoor coil and outdoor coil. Too much short cycling, turning on and off quickly, makes the motor see an enormous amount of damaging heat and energy on every start-up, time after time after time.

When your system is twice the capacity that it needs to be, because only one zone is needing air, it’s going to satisfy that one zone way too fast. On/Off, On/Off, all day long. See, your AC wants to run for longer periods of time at less amperage to cool your house effectively. One to two degrees change for every 15 minutes is not unusual according to Honeywell. But 2 to 3 degrees in five minutes is too fast. I won’t get into this too much as I have several YouTube videos for customers on this topic, but we want to condition the whole room, not just the human. This is how we keep proper humidity levels and prevent wide temperature swings in the room.

What Is the Right Size Unit, Then?

If we were just conditioning that first floor at 1150 sq. ft., what size would we need? Without getting too technical, we would need about a 2.5-ton system. There are factors that would make it smaller or larger, but again I’m trying to keep this short and simple. And what if we were trying to cool just the upstairs bedroom areas at 800 sq. ft? We would need about a 2-ton system. Now, what if both zones happen to be calling for air at the same time? This is where it can get tricky, but for God’s sake, we are NOT doubling the size of the system.

When it comes to heating and air zoning , my rule for our technicians is to size the system a half-ton larger than the largest zone in the house.  In this case it’s 2.5 tons, so we will size the whole system at 3 tons. This is a full ton smaller than the original one installed, which surprises some prospective buyers.  But it’s correct. Because of sizing issues already mentioned in this blog, I can stomach a 3-ton system blowing through the smaller 800 sq. ft. zone without doing major damage to the new system over time, especially if some bleed off dampers like the new Honeywell ARD dampers are installed. This allows the correct amount of air to get to the small zone and any extra bleed-off to the other zone in very small amounts.

Proper Heating and Air Zoning

What happens when both zones reach a point in the day when they are both calling at the same time? That extra half-ton will satisfy one zone or the other first. When that happens, that’s zone closes its damper and allows the other zone to continue until it’s satisfied.

We’re not talking about the laws of thermodynamics to the letter, here. And nothing I say is absolute. Of course, there are variables that your technician will have to take into consideration when it comes to your home, but an experienced installer will know what is right and what’s not when it comes to zoning your house.

For a deeper dive, you may want to view our videos:  What Temperature Should I Set the Thermostat in My House? and What’s the Best Way to Cool My Two-Story House?  Both have a lot of good information you may not have known about your AC system, so I hope you enjoy them.

When Two Zones Don’t Make Sense

Let’s talk about certain lifestyles where it doesn’t make sense to have a two-zone air duct system. I just had a customer who has a nursery and kids’ playroom upstairs while the caregiver and other relatives occupy the downstairs portion of the house throughout most of the day. What’s more is their demand for cooling is considerable given that they like it to be 72 degrees upstairs during the day for the kids and would like it to be 70 to 72 degrees downstairs at the same time of the day for those downstairs. And they expect those temps even on the hottest days of the year. That’s not the way zoning works.

Here’s How Heating and Air Zoning Works

As I mentioned in the video about How to Cool Your Two-Story Home, the typical home we work on is one where a parent stays home with a child, or retirees that don’t have to go to work anymore, so there is usually someone home most of the day. I tell people in these homes to focus on running the AC downstairs where they typically are throughout the day. So, if you like it 75 degrees in your normal living areas, make it 82 upstairs, in the area you’re not using. Run the AC primarily throughout the day downstairs at whatever temperature you’d like, until about 6 or 7 pm. Then, shut the thermostat off for downstairs and have the upstairs start cooling off so that by the time you get to bed, it’s cool enough upstairs to sleep for the whole family.

It’s already 75 degrees downstairs when it shuts off, so it won’t quickly warm up and make it uncomfortable for you.  Set the downstairs to be 82 degrees, where no one needs the AC running. It won’t get there overnight, but at least the system doesn’t come on downstairs, so the AC can focus its efforts on cooling down your second story as quickly as possible.

Saving Money with a Smaller System

You can set it up however you’d like on your thermostat’s schedule. If you need help with that, call or text us and we’ll get out to you and set it up. The main reason for having two thermostats is simple.  The system is not sized big enough to cool the whole house at once.  Because it’s designed to cool one floor, or one zone at a time, your home’s two-thermostat AC system is designed a little smaller.  We save money with smaller systems.  Efficiency is a huge concern for lots of people around the Sacramento Valley.  The smaller the system, the less we pay for the electricity used to run the AC.  When we don’t try to cool the entire house at once, we also save money and energy.

Summary

I hope this helps explain a little more about heating and air zoning, and how to use it properly. The intent was to enlighten folks that running both zones at 73 degrees all day isn’t the way zoning works. Think of it as two separate zones that we are conditioning at two separate times of the day. If both zones happen to call for cooling at the same time, a properly sized air conditioner will manage its way through it.  It will satisfy one or the other zone first, and then give the full system to the lagging zone.

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

HVAC Zoning: What You Should Know Before Retrofitting Your Home

 

Are you dissatisfied with the level of comfort provided by the HVAC system in your Sacramento home or business premises? Let’s review some helpful information to determine if HVAC zoning will fix your problem.

What Is HVAC Zoning?

HVAC zoning refers to the creation of different sections/zones within a building so that the settings of the HVAC system can be customized for each of those zones. For example, you can divide your home into three zones. You can use different heating or cooling settings in different zones even if one HVAC system serves the entire building.

Think about zoning as the installation of different light switches for each room in the home. You don’t have to switch on the lights in the entire house because you want to read late at night. Similarly, you don’t have to lower the temperature of the entire house just because your bedroom is too hot for your liking.

What Are the Required Zoning Components?

The zone control panel.

This is the “brain” of the entire zoned HVAC system. This control panel receives the requests made by the different thermostats and triggers the execution of those requests.

For example, the thermostat in the kitchen may call for extra cooling while someone is cooking. The zone control panel receives that request and widens the damper to the kitchen so more conditioned air is directed to the area. The zone control panel is like a choir director who ensures that everything is working seamlessly.

Thermostats.

You will need as many thermostats as there are zones in the building. The thermostat in a given space allows the occupants of that space to select their desired temperature settings.

Zone Dampers.

Think of zone dampers as “valves” which regulate the flow of conditioned air and heating into a zone/room. The damper executes the instructions sent by the zone control panel after getting information from the thermostat in a given zone/room. For example, the damper will close and reduce the flow of conditioned air if the room/zone has reached the desired temperature.

The dampers can be placed inside the ducts (in-line dampers) or they can be placed on the air registers. In-line dampers are usually preferred in case a new HVAC system is being installed. The dampers are usually placed on the air registers during retrofit applications in which access to the ductwork is difficult or expensive.

Bypass damper.

A bypass damper is a special kind of damper that releases excess pressure in the HVAC system. This happens when most zones have signaled (through the thermostat) that no heating or cooling is currently needed. The conditioned air of the HVAC system would overstrain the remaining zones which still require heating or cooling. The bypass damper deals with that excess pressure/conditioned air by channeling it to the return air register or directing it to a common section of the building, such as a hallway.

Is HVAC Zoning Recommended for All Sacramento Buildings?

HVAC zone control isn’t a requirement for all buildings even if every building can attain benefits from this upgrade. The situations below represent examples of those who would reap the greatest benefits from HVAC zoning.

Buildings with extensions.

HVAC zoning can be helpful if an extension, such as an additional bedroom or finished basement, was added and has unique heating, cooling, and air conditioning requirements. For example, a room added above the garage may be hotter than other bedrooms in a home. Zoning addresses the unique needs of such an extra room.

Multiple levels.

Buildings with multiple levels need HVAC zoning since each of those levels is unlikely to have the same HVAC needs. For instance, the ground floor may be cooler than the upper floor during the summer.

Different occupancy levels.

Buildings with sections that are rarely used can benefit from HVAC zoning. This is because the areas which aren’t used a lot can have their air conditioning turned off. Rooms with lots of occupants can also have their HVAC settings adjusted.  This will address the needs of that larger number of people who may feel hotter than those who are in a room with fewer occupants.

Single-level homes may not require zoning unless a Sacramento HVAC professional inspects the building and recommends that zoning is necessary.

How Is HVAC Zoning Done?

The way in which HVAC zoning is done in Sacramento depends on two key factors. First, what zoning system have you selected? Secondly, when is the zoning being done?

HVAC zoning can be done by installing different HVAC systems for the different “zones” created in the building. Zoning can also be done by redesigning an existing system so that different rooms/zones can be controlled independently from other zones. Ductless air conditioning systems can also be used to zone a building.

Project Timing

The timing of the project also impacts on how it can be done. For example, a new building can have the zones designed prior to the selection of an HVAC system. In such a case, the ductwork will be installed with the zones in mind. However, retrofit situations may dictate that the least intrusive method. Such as installing dampers on air registers instead of inside ducts. Your heating and air conditioning professional in Sacramento can assess your specific situation and advise on how zoning should be done.

HVAC zoning can deliver numerous benefits, such as increased equipment life and lower energy bills, to homeowners in Sacramento. Discuss your needs with an HVAC replacement technician so that the best approach can be designed to zone the system in your home.

Benefits of HVAC Zoning

Have you heard about HVAC zoning?  Wondering if it would be worth it to retrofit your heating and cooling system with a zone control system? Read on and discover some of the key benefits which technicians at Fox Family Heating and Air attribute to zoning the HVAC system in your residential or commercial property.

Enhanced Comfort

The primary reason why HVAC systems are installed is to give building occupants comfort. HVAC zoning takes this comfort to a higher level. This is because every zone or section of the building can have its temperature controlled independently. For example, the rooms upstairs may be warmer than those on the ground floor. HVAC zoning allows the people upstairs to lower the thermostat settings without causing any inconveniences to those downstairs who don’t want that lower temperature.

Reduced Energy Consumption

HVAC zoning also reduces the amount of energy which is used to cool or heat the premises. These energy savings arise due to the adjustments made for each zone based on the needs of the occupants. For example, you can increase the heating to the bedrooms upstairs during the cold months while reducing the heating downstairs since no one will be in the living room or kitchen at night. You’ll get energy savings by not heating unoccupied rooms downstairs.

If all the lights in your home were controlled by one switch, you’d get similar results. Such a situation forces you to leave lights on in the unoccupied rooms, wasting energy. Zoning prevents such wastage. These energy savings can even offset the investment you made to your Sacramento heating and air conditioning company to install HVAC zoning in your premises.

Convenience

More convenience is another benefit of HVAC zoning.  You may need to walk downstairs in the middle of the night to adjust the settings of the thermostat. With heating, cooling and air conditioning controlled from a central location, buildings without HVAC zoning will come with such inconveniences.

Zoning brings convenience since the thermostats of the different zones will be located within those zones. Consequently, you will take a shorter walk to adjust the settings on the thermostat regulating the conditions in the affected room.

Prolonged Equipment Life

Your HVAC equipment is likely to experience less wear and tear if you installed a zoning system. This is because there will be few occasions when the system will be operating at full capacity. For example, the bedrooms may require less heating or cooling during the day.  This is when most activities in the home take place in the living room and the kitchen. Similarly, the living room and kitchen will require less heating or cooling at night while you sleep. This phased demand for heating or cooling allows the HVAC system to operate at less than full capacity during most hours of the day. You will, therefore, have a reduced need to pay for air conditioner repair (Sacramento).

As you can see, HVAC zoning will enhance the value you get from your heating or cooling system. However, those benefits can only come if the zoning system is installed correctly by an experienced professional, such as those at Fox Family Heating and Air.  Get a professional assessment of your requirements before choosing the best HVAC zoning system for your home.

What’s the Best Way to Cool My Two-Story House?

cool your house with Fox Family HVAC

Making the Most of Your Air Conditioner This Summer in Sacramento

As an HVAC technician, I have the comfort in my two-story home dialed in.  The upstairs is just as big as the downstairs for the most part.  But in the summer, the heat rises so dramatically to the second floor it seems I’ll never get the second floor to cool down by the time we go to bed.  Knowing how to control the summertime temperatures in your Sacramento area home can be a bit of a mystery for some.  That’s what we’re going to talk about today on Fox Family Heating Air and Solar!

Intro

As the typical 100° day begins, you have a nice cool attic and rooms throughout the house are at the nicest temperature they’ll be at all day.  If we could just keep our homes at this summer morning temperature, we’d literally be in paradise.

But by 9 am you can feel the warmth already pouring in through the sliding glass door.  If you don’t turn your AC on soon, it’s going to start warming up in the house.

Do you have one thermostat in your home or more than one?

If you only have one thermostat but your home has two levels, an upstairs and downstairs, then your AC system is intended to cool the whole house at one time.  It’s a “single-zone” air conditioning system.  If you have two thermostats, whoever installed your home’s HVAC system set it up to have “two zones”, upstairs… and downstairs.

If you have one thermostat that turns on the air conditioning system, you may notice the upstairs is still warmer than the downstairs, or vice versa, even when the system is supposed to be cooling.  Downstairs where the thermostat is it says 75 degrees and it feels like 75 degrees.  But upstairs you know it’s 80 degrees because the meat thermometer you got from your kitchen accurately reads 79 to 80 degrees upstairs.

Yes, change your filters, yes check the batteries in your thermostat, but we know that’s not the issue here.  The issue here is that downstairs gets more air than upstairs.  So how are we going to fix that?

A Weekend Project

Getting a thick blanket of insulation in the attic is critical to keeping your cool air in your home.  So, if your insulation levels are low, this is a low-cost weekend DIY project for that certain handyman in your home, or you can hire a contractor like us to come out and do it for you.

Whole House Fans

A whole house fan is a great idea for mornings and late evenings, but any time after 10 am, you’ll just be bringing in the hot outside air, so most people are going to resort to their AC system.  If you want to know what a whole house fan is and what it can do for you check out my video on installing a Quiet Cool whole house fan.

Any time after 10 am, most homes in Sacramento are starting to run their AC’s and will continue cycling that AC on and off throughout the day until about 11 pm or later.  If you only have one thermostat, chances are that one floor cools better than the other.  The reality is just that.  The people who installed the system ran all the pipes and ducts where they were supposed to go.  But they just didn’t quite finish the project when they walked away with unbalanced airflow issues in the house.  This is really common in new homes where teams of install crews are literally just slamming these systems in so they can do the next one tomorrow and move on.

Installing a Manual Damper

What we try to do in these cases is find the part of the house that is blowing more air upstairs or downstairs.  Then we’ll cut into the ductwork and install a manual damper.  A manual damper is round like the ducts in your house.  It runs in line with the duct and has a paddle on it that opens and closes allowing more or less air through it and on to the rest of your house.  If we can adjust this manual damper or in a few cases, a series of manual dampers, we can adjust the airflow accordingly in your home.  This is the way we can balance the airflow in your two-story home if you only have one thermostat.

You might ask “why don’t we just shut off the registers around the house until we achieve that?” You can… but it’s not recommended as a practice by HVAC professionals because the registers can start whizzing and making noises.  The pressure of the air trying to enter the room can cause the registers to start vibrating and rattling, which causes other issues.

A Fine Balance

The air conditioning system has a sort of blood pressure to it.  When we start shutting down registers around the house it affects the system’s static pressure.  If the air can’t get out of the system, expensive compressors start failing, motors start seizing up, and your HVAC system gets to a point where it doesn’t want to cool the home anymore.  There is a fine balance point we are trying to achieve here with this static pressure, so letting an AC tech balance your ductwork is recommended for the longevity of your system.

If you have two thermostats, you have a zoned system which will let you decide whether you want the downstairs AC on or the upstairs AC on.  Does this sound enticing to you?  If you don’t have this setup currently, it can be done on any AC system in the Sacramento region.  It usually takes a good amount of labor for people to take a system that only has one zone and make it have two zones, but it can be done.

A Typical Sacramento Household

The typical home we work on is one where someone is home most of the day, like a parent staying home with a child or for retirees typically home most of the day.  I tell people in these homes to focus on running the AC downstairs where they typically are throughout the day.  If you like it 75 degrees in your normal living areas, set it to 82 upstairs, in the area you’re not using.  Run the AC primarily throughout the day downstairs at whatever temperature you’d like, until about 6 or 7 pm.  Then, shut the thermostat off for downstairs and have the upstairs start cooling off so that by the time you get to bed, it’s cool enough upstairs to sleep for the whole family.

It’s already 75 degrees downstairs when it shuts off, so it’s not likely to warm up super-fast and make it uncomfortable for you.  Nobody needs the AC downstairs during this time so set the downstairs to be 82 degrees.  It won’t get there overnight, but at least the system doesn’t come on downstairs, so the AC can focus its efforts on cooling your two-story home down as quickly as possible.

Master of Your Castle

You can set it up however you want on your thermostat’s schedule.  If you need help with that, call Fox Family or text us and we’ll get out to you and set it up.  Having two thermostats makes sense when the home’s system isn’t big enough to cool the whole house at once.  Your home’s AC system with two thermostats is designed a little smaller.  This is because it’s designed to cool just one floor or one zone at a time.  For many people in the Sacramento region, they can save money and maximize efficiency by using smaller systems.  The smaller the system, the less you’ll pay for the electricity it takes to run the AC.  We can also save money and energy when we don’t try to cool the entire house at one time.

Use Your Thermostat Effectively

If you have a one-thermostat, two-story home that is 1500 sq ft or more, you might have uneven temperatures.  If upstairs and downstairs are at different temperatures, balancing the ductwork will correct the issue.  This means upstairs and down receive the appropriate amount of air to cool the house more evenly.  If your house has two thermostats and still have uneven temperatures, learn how to use your thermostats more effectively.  Learn to control the temperatures in your home.  Have the AC on downstairs during the day, while upstairs stays off or is set higher, such as 82 degrees.

Summary

I hope this has given you some good information on how to cool your two-story home more effectively.  If you need any advice or help with this, let me know in the comments down below.  I’d love to start a conversation about homes with two zones.  How do those homeowners strategize their airflow throughout the day?

Thanks so much for watching and we’ll see you on the next video.

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