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Air Ducts and Registers; Why They are Important

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What Are Air Ducts and Registers?

Air Ducts and Registers

Air ducts are the intricate system of tubes and related parts that distributes the airflow of your air conditioner (and HVAC system at large) throughout your home or commercial building.

Registers at the end of each air duct direct the airflow within a room or space. Supply air registers are not returns; they do not bring air back into an HVAC system. A return will have a permanent, unmovable grille. In addition, supply air registers and returns are also called “vents”.

Where Are Air Ducts & Registers Located?

Air ducts are located behind walls and floors and are visible in crawlspaces, attics, and basements or cellars. Some split-system air conditioners do not use conventional ducting, though ductless air conditioning may not be right for all homes or businesses.

Registers are installed on metal cans in the opening of a wall. For example, either up high toward the ceiling or near the base of a wall. Also registers are found in floors in older homes .

How Do They Each Work?

Apart from the air ducts themselves, ducting includes other crucial components:

  • Vibration isolators, which minimize an operating HVAC system’s vibration
  • Metal cans allow the flow of air to move from the ducts to the registers
  • Dampers, which adjust the volume of air
  • Vanes, which smooth out air flow around turns

in order to have a balanced, comfortable home, careful sizing and placement of return and supply air ducts and registers is important.

Registers have bars that you can control with an adjustable damper (a lever, knob, or another movable part on one side of the register) to reduce or direct airflow.

What Makes Them Important?

Ducting acts as the arteries and veins of your air conditioning system. They deliver the right amount of cool air to each room in your home or commercial space.

Registers help control the comfort level of a space by providing a way to direct airflow at the point it enters a room.

Different Types of Air Ducts and Registers

Flexible Ducting

Ducts come in many, many styles and shapes, including oval, round, and rectangular, and they are formed from materials as varied as fiberglass, galvanized steel, aluminum, polyurethane panels, and plastic. Don’t be confused by pipes that transfer refrigerant or other vapors and liquids; air only moves thru ducts.

Registers come in various materials, including aluminum, steel, and even wood. Many people buy registers and returns with custom-designed slats or decorative covers.

(Note: for a list of outdated ductwork in the Southern California, check out this blog post.)

Maintenance and Repairs

Do you smell a faint, musty scent of dirty laundry? That could indicate mold is growing in your ducting. You may want to call a professional technician to inspect your ductwork. They can detect the presence of mold and accumulated dust, which can make you sick.

Despite the name, duct tape is not suitable for sealing up ducts. Instead, to ensure ducts don’t leak, heat and uv resistant tape is used .

Though vents are not the typical cause of an HVAC malfunction, they can contribute to one. Check registers for any debris that builds up. Or for loose, cracked, or broken vent covers. When switching out vent covers, be sure to take accurate measurements to purchase the correct replacements. Occasionally wipe your registers with a damp cloth to remove any accumulated dust and debris.

Save Energy, Improve Efficiency With A Ductless Mini-Split

What is a Ductless Mini-Split System?

Unless your heating and air conditioning system has been recently updated, chances are your home is using a ducted system for heating and cooling. Did you know there are more efficient and quiet options available? Ductless systems are a great choice because they don’t waste the energy typically lost through cracks and leaks in ducts.

If you’re looking for an eco-friendly heating and cooling system that will provide comfortable temperatures in your home year-round, perhaps it’s time to consider a ductless system. Check out what options are available to you below.

Overview of Mini-Split Systems

The concept of a ductless mini-split system is simple. Each system includes an outdoor compressor along with indoor air-handling units connected to the outdoor unit by a refrigerant line.

Installation is simple and unobtrusive since there’s no need for ductwork. Ductless systems also require less energy to run than traditional units. These systems usually only require a small three-inch hole in the wall to run the conduits between the indoor and outdoor units.

In general, there are three types of mini-split systems:

Single Zone

A single zone system consists of only one indoor and one outdoor unit. This is ideal for a single-zone space, such as a one-room addition to your home or if you’re installing heating and cooling for a garage or outbuilding.

Multi Zone

A multi-split system connects several indoor units to a single outdoor unit. Unlike the single split system, the multi-split system allows you to create multiple zones in your house where each one can be controlled independently.
You can choose a different style and capacity unit for each zone in the home, providing a customized experience for each room. These different styles include:

  • Wall mounted unit
  • Ceiling unit
  • Hidden unit

Each outdoor unit can usually accommodate 4 zones.

Flex Zone

A flex zone system gets a bit more complicated. Like a multi-split system, you can connect many indoor units to the same outdoor unit, but the flex zone system allows for more indoor units.

The difference is that in a multi-split system, each of the units has a line running back to the outdoor unit. That’s not the case with a flex zone system. Instead, you might have only two lines running back to the outdoor unit, and then each one “branches” so the system can accommodate up to 8 zones.

While the multi-split system must be controlled via each indoor unit, you can control your entire home’s temperature through a single control with a flex system, which allows for better management.

Heating and Cooling Options

Before you jump on buying and installing one of the above systems, it’s important to note that there are different options for each. The most common is an air conditioning only system. These systems function like your typical air conditioning unit—only without the ductwork. In other words, it only functions to cool your home.

If you live in a climate where heating and cooling are equally important, then you’ll want to consider a heat pump. The heat pump system not only cools your home, but it can reverse the functions and heat your home by reversing the refrigerant flow.

Which Option Is Best for Your Home?

Deciding which option is best for your home will depend on numerous factors. The size of your home, for instance, can help determine how many zones you need.

Also consider if you’d like to completely replace your heating and cooling system or if you can use your home’s current duct system to supplement temperatures changes throughout the home. For instance, you could place a single-split unit in the main living area of your house and then use your current system for the bedrooms when needed.

If you need to manage different areas of the home independently, then a single-split system isn’t going to cut it. For instance, upstairs bedrooms may need cooling power while the basement may need to be heated. In that case, a multi-split unit is ideal.

If you’re not sure which option is best for your home and needs, contact a professional in your area for personalized advice.

Out With the Old: Common Outdated Ducts in Southern California Homes

Different ducts in your home

If you have a home with old duct work, you are likely throwing money out the window. The California Energy Commission reports that the average duct system leaks 30 percent of the air that flows through it. Take a look at five older duct types that are common in Southern California and see if you can recognize your type in this list:

Rigid Round Duct

Ridged Round / Super Round Ducts

– These are round ducts made entirely from formed fiberglass. As the fiberglass is exposed to the airstream, it finds its way into the home when it deteriorates. The R-value (or the capacity of the insulating material to resist heat—the higher the R-value, the better) is medium to low and these ducts tend to have a lot of leakage at all connection points.

Unlined Flex Duct

Unlined Flex Ducts

– These are round flexible ducts with fiberglass insulation wrapped around a spiral metal wire core. The fiberglass is often fully or partially exposed to the air stream, which can cause problems as it deteriorates. Debris gathers on the inside walls easily. R-value is medium to high, and leakage occurs due to tearing and older duct tapes that break down in attic heat.

Insulated Tin Ducts

Tin Ducts

– These are usually smaller round metal ducts that lack galvanizing and tend to rust inside. R-value is very low due to poor, thin insulation wrapped around the outside, which gets torn or falls off the ducts. This type of duct work has high leakage due to rarely sealed connection points that are often just screws or welds.

Galvinized Duct

Galvanized Metal Ducts

– With these types of larger round metal ducts, there is actually efficient airflow from lack of friction. However, poorly hand-wrapped insulation on the outside lowers R-value to give it medium to high air leakage depending on the type of sealing at connection points. With this system, fiberglass is not exposed to the air stream.

Grey Duct

Flex Ducts (Grey)

– These are insulated flexible round ducts found in many tract homes. They are made of a metal spiraled core with a plastic inner liner wrapped in R-4.2 fiberglass insulation and covered in a grey plastic outer jacket. The outside jacket of these early flexible ducts easily deteriorates from the UV light and allows the insulation to fall apart, finally exposing the inner plastic liner to the heat and UV elements. Ultimately, this type of system breaks apart and the result is major air leakage, along with dust and debris infiltration.

So what can homeowners do to improve air flow efficiency once they’ve identified old and outdated materials? Take a look at just a few suggestions:

Modern Flex Duct

Upgrade to Flex Duct (Silver Metalized Jacket)

– These are the newest generation of flexible ducting that features upgraded materials to protect against UV and temperature damage. They have a higher R-value and, if installed properly, can produce as little as 6% leakage.

Seal ducts. If you can avoid it, do not use duct tape or any other temporary sealing fixes. You want your duct repairs and efficiency improvements to last as long as your ducts do. If there are leaks in your ductwork that are smaller than a quarter inch, you can apply a bead of mastic. If the leaks are wider than that, apply mastic that is at least 3 inches wide and runs the entire leak length. After that, apply a coat of fiberglass mesh, at least 2 inches in width, and then put another layer of mastic on top of that. The process is not especially difficult, but if you have never watched someone do it before, it can be tedious. You might fare better to ask a professional like Bob Jenson to help you with your sealing project.

Add duct wrap. Flexible ducts and duct board generally have strong R-values, but if you have sheet-metal ducts you may want to add some extra insulation with the help of duct wrap. This does not actually fix leaks but it will keep the air from completely escaping the duct system.

Imagine the savings over time on your utility bill if you were able to prevent the cost of duct leaks. If your home features duct work that could use a checkup and update, or if you’re interested in ditching the ducts altogether in favor of a ductless system, contact a professional HVAC technician like Bob Jenson Air Conditioning and Heating.

Dangerous Ducts: Are They In Your Home?

Is your ductwork a danger to your health?

Your home is filled with all manner of wires, cables, and pipes, all of which keep your home’s various utilities and appliances running smoothly. One of the most important but often under-appreciated elements in any home is the ducts. They keep air flowing thru your filter and into your home and help remove allergens and other unwelcome airborne debris. Ducts are also what bring us the wonder of climate-controlled rooms. They’re the lungs of your home.
But ducts—or at least those that aren’t well-maintained—present problems. They’re inefficient, raise your utility bills, and generally make your humble home a place of discomfort. Worse yet, bad ductwork can actually cost you your health and potentially your life! Here are some common culprits causing dangerous ducts.


Dust around the house is a fun mix of essentially everything drifting around your home—pet dander, bits of ash from your cigarettes, soil, pollen, insect bits, industrial pollution, and good ole human skin. Ducts that are storing a lot of dust will only blow that dust back into the air, which can cause sneezing, aggravate allergies, and make breathing difficult. Ducting that isn’t sealed well can introduced dust from your attic or under your house right into your home. Don’t let bad ducts get the better of your health and allergies.

Mold and Fungi

Mold and fungi can be found essentially anywhere containing moisture, like the pool of condensation from your air conditioner. A mold spore floating in the air will land in that pool and grow. It will continue to grow so long as there’s some moisture present.

That alone is pretty gross, but it gets worse. Because your ducts consist of a network running throughout your home, the mold has easy access to just about every nook and cranny of your home. Breathing in some mold spores can lead to respiratory issues that often resemble seasonal allergies, in addition to headaches, dizziness, and difficulty concentrating. Frequent contamination could lead to illness and respiratory issues all year long.


Asbestos is a mineral fiber and was used in various products to add strength and fire resistance. It is commonly found in homes that were built before the 1970s. In older homes, ducts are often wrapped using an asbestos blanket or asbestos paper tape for insulation.

When asbestos gets damaged you should start worrying, as it crumbles into a fine dust that is easily inhaled. Inhaling high levels of asbestos increases your risk of lung cancer, mesothelioma, and asbestosis. Symptoms of these diseases won’t manifest until 20 to 30 years after exposure.


Rats are one of the most common pests in the world. When they’re out in the cold, wet wild, your home looks like a haven of warmth, shelter, and free food.

You don’t have to get bitten by a rat to be in danger. They carry fleas, which may or may not harbor disease but are an extreme headache for anyone trying to get rid of them, especially in a non-toxic way. Then there’s the matter of droppings. Gross in their own right, a rat’s droppings and urine contain potentially harmful bacteria. Imagine those droppings sitting in your ducts as you turn on the heater. You’d be filling your home with the bacteria of rat poop. Yikes!


Fiberglass is a man-made material created to replace asbestos as a thermal barrier or insulation in homes today. Fiberglass is found all over your home, in walls, attics, under your house, and it’s also wrapped around your air ducts. When ducts are damaged or deteriorating, they can introduced particles of fiberglass into the air you breath. According to the American Lung Association– Inhaling fiberglass can reduce lung function and cause skin eye and throat irritation, in humans and animals. Some old types of ducting have no barrier between the fiberglass and the air stream and should be replaced immediately.

So, are dangerous ducts in your home? If you’re not sure of the status of your air ducting, call a professional air conditioning contractor like Bob Jenson A/C to assess them. The best way to mitigate any of these dangers is to perform regular maintenance on your duct systems. Keep your ducts clean, practice proper pest control, and have a professional check your ducts once a year.

5 Reasons to Replace Your Old Air Ducts

Ducting – Why Replace it?

For most of their live they go unseen, in our walls, attics, even under the house! Duct are usually out of sight out of mind but they are a critical factor in our comfort, health and energy use at home. Here’s a fun infographic to help you know why and when to replace them:

5 Reasons to Replace Your Air Ducts

What to look for in a quality flexible duct system?

  • UV protected, metalized jacket
  • Sized correctly
  • Sealed from one end to the other
  • HERS Tested for leakage
  • Dampers installed for balancing

Of course there are many other details to understand when replacing the ducting system for your home. We have years of experience in helping customers find the just what they need, call or contact Bob Jenson A/C for free in-home advice on your next duct replacement!

Is it time to Replace your HVAC or Air Conditioning Ducting?

Your Air Conditioning Ducting – Is it replacement time?

Spring is the perfect time for home renovation projects. The weather is ideal, the costs are good, and you’re probably already doing a little spring cleaning anyway, right?

While you’re looking for home improvement projects this year, don’t search any further than your existing air conditioning ducting. If your home uses duct-based heating, ventilation, and air conditioning and you don’t perform annual maintenance, you could be tossing money out the window and exposing your family to harmful toxins.

Read more below to find out if it’s finally time to replace your air conditioning ducting.

duct raccoon 1024x597 1

If it Looks Like a Duct…

Usually, the first hint that homeowners get that tells them its time to replace air conditioning ducting is the increased cost of heating or cooling their homes. If you see a higher energy bill, but the price you pay and the amount of power you use have remained constant, then you may have faulty ducting.

There are a few reasons your ducts could be in ill repair: cracks, holes, or other separations, and dust, grime, or other obstructions restricting airflow.  Poor sealing and installation practices are another. These issues create higher energy bills for you.

Address these things as soon as possible; in fact, they should be taken care of before anything bad ever happens with preventative maintenance performed by professional air conditioning ducting technicians each spring.

But even annual upkeep can’t fight all the problems that occur, either due to old age or average wear and tear. Let’s look at what dangers can result from letting these problems go unchecked for too long.

And it Smells Like a Duct…

Mold—it’s perhaps the worst thing that can happen to your duct system. You’ll notice a moldy or musty smell coming from the vents in your walls.

Mold can form when holes or cracks in ducting release hot air into a cold environment, like the walls of your home. Picture an airplane ascending into the sunset: those white streaks you see left behind are condensation with no place to go. Around your ducts, that condensation collects on the wood behind your drywall. And that’s bad.

Moldy wood breeds lots of harmful toxins, as well as fungus—as in full-grown mushrooms. These toxins are pushed through your air conditioning ducting into all the rooms of your home, including your bedrooms. In addition to toxins, moldy wood is weak and porous and can invite even more problems over time, like termites, carpenter ants, and other pests.

Worst of all? You’re paying extra for that. Since a duct system with holes, cracks, rust or obstructions isn’t performing to peak efficiency, it will cost more for that inefficient system to maintain the temperature you set on your thermostat.

…Then it Must be Time to Replace That Duct!

The answer to all these problems is simple: replacement of your air conditioning ducting. It’s a necessary process in most cases, especially if you fear mold contamination or major leaks.

The benefits to new ducting are many: increased efficiency and lower costs; clean, fresh air instead of musty, toxic air; quieter airflow without obstructions; and the knowledge that you’re maintaining your home’s value instead of letting it decay from the inside out.

As a matter of fact, you may experience some of these benefits even if you don’t see any of the problems. If you are planning a home remodel or major construction that will alter the layout of your rooms, a new duct installation is an ideal solution to ensure each living space is receiving the correct amount of ventilation and air conditioning.

If you suspect that you have any problems that are causing your ducts to act abnormally or undersupply you with cool or warm air, call Bob Jenson’s expert technicians right away. We can come to your home at your convenience and conduct a thorough inspection of your ducts to see what problems exist and talk with you about the best course of action to take.

Many times old air conditioning ducting can be replaced quickly and easily, our friendly team will gladly help you get your duct installation up and running. Bob Jenson is known for their professional San Diego duct installation, and we have been since 1977.

Call today to find out how easy it can be to replace your HVAC ducting. Remember, now is the time for spring cleaning, so don’t wait to call!

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