Duct Renovation Assumptions

A common belief is that duct renovation means tearing out an existing duct system and starting over from scratch. I’m embarrassed to admit that my own family company followed this line of thinking for many years until we learned a better way.

Another common duct renovation approach is to guess and then rip stuff out. Sometimes it works. Sometimes it fails miserably. In my family’s business, we did what we thought was best with the knowledge we had at the time.

Unfortunately, many in the industry follow the same approach we did. They put too much trust in the rules of thumb they learned from their mentors. No one thinks to question whether these rules are right or if there is something more to them. Sometimes, following these rules leads to the duct system operating worse than the original installation.

We unknowingly set ourselves up for failure because we were missing something. I just didn’t know what that something was until that fateful day in Louisville, Kentucky when I met Rob Falke and Al D’Ambola. There was a better way, and we found out it doesn’t have to be complicated.

Two Duct Renovation Approaches

To better understand the purpose behind renovation, it helps to look at the meaning of the word “renovate.” The Latin word for renovate is novare. which means “to make new.” So, when you renovate a duct system, the goal is to make it as new as possible and reduce efficiency and performance losses.

The biggest limitations to a duct renovation project are how much your customer wants to invest in the project and how much space/access is available. You may even find that you are a big limitation. There were multiple reasons I initially failed in duct renovation. You can read about four of them here.

So here are two approaches that address specific customer problems you need to solve. One approach focuses on making sure the equipment performs to manufacturer specifications. The other dives into addressing more advanced problems like uncomfortable rooms, dust, and humidity issues.

Both approaches use field measurements, manufacturer specifications, customer feedback, and industry standards. These help you design a scope of work that meets the goals of everyone involved. One approach keeps it simple and fast. The other goes much deeper. Let’s look at each approach in more detail.

The Air Upgrade Approach

The first duct renovation approach is an Air Upgrade. It is a set of prepackaged, flat-rate repairs designed to improve equipment static pressure and airflow. They are a great fit for anywhere there is limited duct system access, like a finished basement or multistory home.

The goal of an Air Upgrade is to achieve static pressure near to manufacturer specifications and fan airflow within ± 10% of required airflow. To discover Air Upgrade opportunities, you must measure static pressure and fan airflow. A visual inspection will reveal the obvious, but field measurements put data behind these observations.

Most Air Upgrades don’t add much additional time to the job. You can usually incorporate them during equipment replacement or upgrade as part of a better package.

Air Upgrade Features

Since Air Upgrades focus on improving static pressure and fan airflow, the air-handling equipment receives much of the attention. However, that shouldn’t stop you from making repairs to the duct system, as needed. Here are some of the most common improvements listed by location.

Equipment improvement features include:

• Rework filter system to reduce filter pressure drop
• Improve and enlarge duct fittings at the equipment
• Provide basic system cleaning
• Test, adjust, and set fan speed
• Readjust refrigerant charge

Duct system improvement features include:

• Add one oversized return duct and grille into a large open area
• Replace three or more 6-inch supply ducts with 8-inch ducts and balancing dampers
• Seal accessible duct leakage to reduce airflow loss
• Add strapping to support the flex duct system
• Replace restrictive duct fittings
• Upgrade grilles and registers

Sometimes an Air Upgrade won’t do the job. Your customer may want a higher level of comfort that requires work beyond the pre-packaged repairs in an Air Upgrade. This is when it’s time to offer another duct renovation approach.

The Duct Optimization Approach

Duct Optimization is the second approach to duct renovation and is fully customized. To discover it, you offer the customer airflow diagnostic testing and design work for an additional fee. The customer invests in your time and expertise to address these advanced problems. With their help, you both discover needed repairs based on field measurements while making the customer a detective in their home. It’s a fun way to engage your customers and focus on the skills that separate you from the competition.

The goal of Duct Optimization is to deliver heating and cooling within ± 10% of design specifications. This is tougher than it sounds.

Like Air Upgrades, you can incorporate Duct Optimization during equipment replacement or upgrade. However, you’ll rarely complete this level of work during the time frame of a typical replacement. Depending on the project, it can take more than one day to complete. If appropriate, you may choose to offer this profitable work to your customers during slower times to keep your installation crews busy.

Some ducts are out of sight and hidden above drywall. To access them, you can add a false return grille as an access panel. Be sure you add a piece of metal painted flat-black and insulation above the grille.

Duct Optimization Features

Duct Optimization involves applying industry best practices to achieve the promised results. It is common to include most Air Upgrade features in this next-level package.

There is also a focus on equipment components and ventilation. It’s common to replace the indoor coil and add ventilation and dehumidification to these projects. Once again, many of the choices depend on customer feedback and expectations.

Duct Optimization features include:

• Low pressure-drop indoor coil
• Properly sized air filter
• Controlled ventilation
• Low total equivalent length (TEL) duct fittings
• Proper duct sizes
• Balancing dampers in all branch ducts
• Sealed duct joints
• High R-value duct insulation
• Performance-grade registers and grilles

These features help create a safe, healthy, comfortable, and energy-efficient environment. However, there are field realities that you must deal with. Sometimes, the building can beat you and hinder even the best optimization project. So be careful about promising perfection. Space limitations, rooms with crazy loads, duct locations, building insulation, access to ducts, finished ceilings, and tight crawl spaces will all hinder what you can realistically do.

Which Approach is Best?

The short answer is “it depends.” There are many ways to find out which approach is best. If the building beats you and you’re limited on what you can do, you may have to find an acceptable middle ground. Other times, you may have a lot of options to choose from.

Besides options and external obstacles, there are also internal obstacles to address. Sometimes, the biggest obstacle is your installation team. They will unknowingly limit your choices.

Depending on the structure of your company, the installation team may handle all duct renovation work. Unfortunately, some installers think ductwork is beneath them. I’m not saying you should pander to these types. However, it’s smart to have options.

One opportunity is to build a new role in your company to handle this work that frees up your regular installation teams. That role is a duct renovator with specific skills to upgrade and renovate duct systems. I’ll dedicate an entire article to them later in the series.

There are also multiple factors to consider before you jump into renovating a duct system. If you plan for them, duct renovation implementation is a lot easier. Next month, we’ll look at four major factors that influence duct renovations and how you can plan for all of them.