YelpCall us today at: (480) 428-0600

duct seal, repair, and replacement

The Importance of Air Ducts

Duct systems are the single most overlooked and under-rated component of an HVAC system. Duct systems must be carefully designed and properly installed or the benefits of an efficient structure and high or standard efficiency HVAC equipment will not materialize.

If you have any concerns of hot and cold spots in your home then call us right now, we’re a Scottsdale duct repair company and can fix your problems.

Ducts exist in the walls, in the attic, on the roof, just plain out-of-sight and out-of-mind. What most of us do not realize is that duct systems are a vital part of heating and cooling our homes in Arizona. More than just the existence of them, they have to be designed properly, installed properly, insulated properly, and in good condition to be an effective component of our entire HVAC system. It is not safe to assume that just because they’re there that they’re doing the best they can do for you. It is also not safe to assume that since the home builder installed them that they’re done right.

Time and time again heating and cooling equipment is being replaced without a mention of the duct system. If your equipment has reached its life expectancy shouldn’t the duct system be considered for replacement as well? After all, how long should a duct system last anyway? Simply replacing ONLY your AC unit will almost guarantee that the designed efficiency will not be achieved, that your hot and cold spots will continue to be an area of discomfort, and that your new unit will likely suffer from a shortened life span.

Duct systems have a direct and significant effect on:
  • Equipment Size
  • Equipment Efficiency
  • Equipment Malfunctions
  • Envelope Infiltration
  • Operating Cost
  • Indoor Air Quality
  • Noise Levels
  • Occupant Comfort
  • Owner Satisfaction

proper ductwork airflow

Duct systems carry our conditioned air and distribute it throughout our homes.

Considering that our AC systems account for the single largest consumer of power in our homes, we should be motivated to ensure that every bit of air gets where it needs to be. To accomplish this there are a few things that we must have:
duct repair

Manual D

First, we need a properly designed duct system according to Manual D. Manual D is the procedure that professional HVAC contractors like us use to design duct systems. Manual D contains the calculations, formulas, procedures, and dynamics that are required to properly design duct systems. Trust us, the math involved is complicated. Without Manual D its anyone’s best guess. Manual D is used in conjunction with Manual J. Manual J is the methodology we use to determine a buildings heat load. Without a Manual J you have no Manual D. What’s important is that we use these tools to do the job right to get the results that you want.
ductwork installation

Proper Installation

Second, we need the duct system to be properly installed. Don’t let this part fool you, installation is not as easy as it may sound. Duct installation takes skilled and experienced tradesman aside from sheer determination to do the work in our summer temperatures. The best designed duct system is only as good as the installation. In the case of duct system replacement which is our specialty it’s even harder to get right. Working within the confines of an occupied residence poses many challenges and makes the difficulty level extremely high. The good news is, we do it every day and know what it takes to get the job done right.

Duct Seal

Third, we need a tightly sealed duct system. You pay for the air conditioner to condition the air so you do not want it escaping or being diluted. Supply ducts are under positive pressure which is the side of the duct system that is subject to air loss. Losing conditioned air to the attic is no different than running your air conditioner with the windows open. The return ducts are under negative pressure. The return ducts are subject to infiltration and dilution from unconditioned and unfiltered air. The return side of the duct system is what contributes to poor air quality and excessive dust. Both the return and supply ducts should be thoroughly sealed and tested to ensure tightness.

Common Duct System Problems

  1. Crushed ducts – This condition results in restricted airflow
  2. Disconnected ducts – This condition results in lost airflow
  3. Kinked ducts – Similar to a crushed duct this condition results in restricted airflow
  4. Duct sagging – This condition increases the resistance in the duct which reduces the velocity of the air. Flex ducts should be pulled tight so the wire helix is fully stretched.
  5. Acute duct radius’ – This condition cause turbulence in the duct which slows down airflow. The inside radius should be equal to the duct diameter.
  6. Stamped registers & grilles – These types of registers and grilles restrict the amount of passable air through them
  7. Undersized return ducts – This is one of the most common problems in the Greater Phoenix area. It’s a problem we encounter every day in the field. An air handler can only supply as much air as it returns. Undersized return ducts starve the air handler of air and cause a variety of subsequent problems from extended run times, increase wear and tear on the indoor fan, and a poor refrigeration cycle. Not to mention a large reduction in the designed energy efficiency that affects the SEER and EER ratings.
  8. Under-insulated – This condition causes the temperature of the air inside the duct to diminish. Ducts located in unconditioned spaces like the attic should be insulated to an R-Value of 8 for our climate zone in Scottsdale.

Problem Indicators


If you experience any of the following problems, your ductwork may be the cause:
  • Excessive AC unit runtimes
  • Hot & Cold spots
  • Excessive noise
  • Excessive dust
  • Frequent AC unit breakdowns
  • Concaved air filter
  • High utility consumption
  • Highly pressurized rooms
  • Excessive On/Off cycles

Are you asking yourself any of these questions?

  • "Why is my room hotter than the rest of my house?"
  • "How can I increase air flow from my air conditioner?"
  • "Why does my house get hotter at night?"
  • "How can I get rid of the hot and cold spots in my house?"
  • "Why is there very little air coming out of my vents?"
  • "What does it mean when water is leaking from my AC vent?"
  • "Why is my house so dusty?"
  • "What is causing my air conditioner to leak water?"


Leaky Ducts and the Relationship to Indoor Air Quality


ENERGY STAR claims about 20-30% of the air that moves through the typical duct system is lost due to leaks, holes, and poor connections. There’s a saying that goes “return leaks suck and supply leaks blow.” Understanding that us Phoenicians live in the hot dusty desert climate it’s a priority to protect our duct systems from that environment.

When a return air leak exists, it will draw into the duct hot dusty unconditioned air and contaminant your ducts and air handler. The result increases the supply temperatures in summer, decreases them in winter, and introduces dust into your conditioned airstream.

With regard to supply leaks, it’s simply air that you paid for blowing right out the door.

A duct test and inspection will aid in identifying these problems and provide you with solutions to remedy.

Duct sealing is an improvement that will often pronounce the problem of undersized return ducts. This is because the undersized return is making up air from leakage areas in the return itself. Duct sealing a duct system with an undersized return is not recommended unless the return duct is first enlarged.

Remember we’re the experts and we’re here to help. If you have any of these problems call us, we’re the solution.

Duct Static Pressure is the Duct Systems Blood Pressure

Static pressure is the form of measurement us pros use to measure the amount of pressure in different areas of the duct system. The amount of static pressure has a direct relationship to how much air the indoor fan can move. Yes air has weight, actually it’s quite heavy when you’re trying to move large volumes. High static pressure can be compared to high blood pressure, it’s bad. Your air conditioning system will have increasingly poor performance the higher the static pressure gets. Undersized returns, kinks, acute radiuses, dirty evaporator coils, and stamped grille returns all contribute to high static pressure conditions. A high static pressure reading is an indication that a problem exists and that further investigation is needed. High static pressure exists in the ducts but has an effect on the entire equipment system including the refrigeration cycle.



What you’ll get when you schedule a Ductwork Evaluation with us:

  • Test your duct system to determine the leakage rate
  • Visual inspection to locate leakage sites
  • Visual inspection to identify common problem areas
  • Provide test results and repair proposal


APS and SRP Rebates for Duct Test & Repair


SRP & APS duct test and repair rebate program offers up to $250 for qualified testing and repairs.
It’s time to stop wasting energy and stop wasting your money. Seal and insulate your duct system today! To schedule your ductwork evaluation, call us at (480) 428-0600!


APS Duct Test and Repair Rebate:
SRP Duct Test and Repair Rebate:




Expert Service and Repair for Every HVAC Brand and Model

  • Small York
  • Trane Logo

Heating & Cooling Unit Replacement Company

  • Lennox Logo
  • Trane Logo
Tap To Call Schedule Service
CTA StarSchedule Service Now!
Contact Us! Larson Air Conditioning, LLC. 15475 N Greenway-Hayden Loop B11 Scottsdale, AZ 85260 Phone: (480) 428-0600
  • To schedule a service or speak with an expert, send us a message below or give us a call at (480) 428-0600.