WHAT IS A QUALITY INSTALLATION?
Oh boy, its 95 degrees outside and my 14-year-old AC just died. It is hot, humid, sweltering and I am sitting in my living room. It’s hotter inside my house than it is outside. Now I have to muddle my way through the arduous process of figuring out what I need, who I can trust, and if they will do a good job.
If you find yourself in this situation and need to replace a furnace/AC or Heat Pump/Air Handler, one of the main considerations for your selection of contractors is the quality of installation. It is sometimes difficult for contractors to detail out what the differences they employ are and why they matter. BUT THEY DO MATTER. The most important day in the life of your Furnace or Air Conditioner is the day its installed.
On average a gas furnace/Air Conditioner system will last 14-17 years, and a poorly installed system will last only 10 to 14 years, but a system installed with best practices will last 20+ years. An Air Handler/Heat Pump system should last 12-15 years on average, with a poorly installed system lasting only 8-12 years. An Air Handler/Heat Pump should last 15+ years when installed under best practices. Most manufacturers agree that 70% of how well your system works is related to the quality of your installation.
So, we hear all the time contractors talking about their construction practices being to code. In general, most HVAC contractors say that they spec their work to code.
The National Institute of Standards and Technology (NIST) defines code as “laws that set minimum requirements for how structural systems, plumbing, heating, ventilation and air conditioning (HVAC), natural gas systems and other aspects of residential and commercial buildings should be designed and constructed.”
These requirements are to set a minimum allowable standard, not what’s going to be best for the system, but basically the least that general contractors can get away with. Code is a vital bar for contractors to be required to uphold, but far from any level of professional acceptance. As a homeowner, it is difficult to decipher the important differences between contractors, especially when they only have to participate in a project like HVAC replacement on average once every 15 years.
THE SUMMIT WAY – THINGS TO CONSIDER
At Summit Heating and Cooling, we do not accept minimum code as our standard. We prefer industry Best Practices as our guide for designing our systems and completing our work.
Industry Best Practice is defined as, the exercise of the skill, diligence, prudence, foresight and judgement which would be expected from a highly skilled, experienced and well-resourced person engaged in a method or technique that has been generally accepted as superior to any alternatives because it produces results that are superior to those achieved by other means.
We take this as doing the job the best we possibly can, according to industry knowledge at that time. We readily admit that sometimes information changes, so do industry practices, and when they do, we are open to changing what we do to match the current best practices.
The first thing that influences the comfort, efficiency, and longevity of an HVAC system is the size. To determine the proper sizing for a home, a heat load calculation must be run. This is a formula that predicts how much heat must be removed from a home on a hot day and how much needs to be added on a cold day. This formula computes the number of BTUs of heat and directs what size system is required for the size and specs of the home. We might consider the size of the existing system, but it is a very small consideration in the recommendation we provide. We are looking at the math for a correct determination.
Another consideration is ductwork. We measure your ductwork to make sure its appropriately sized for the equipment we are recommending. If the ductwork is too small it might be very noisy, or worse not be able to deliver the volume of air required to comfortably heat and cool your home. This can also damage the new equipment or in some cases freeze up a system causing it not to work at all. We also count registers. This makes sure we can deliver the volume of air we are producing, as well as evenly distribute the conditioned air throughout the home.
If the ductwork is too large it can be difficult for the system to move the volume of air required. This is called dead air. Most importantly, we look at return. The return air is the air coming from your home to the furnace or air handler. It is vital to have proper return in your home. If we can’t get the air back to your furnace, we can’t condition it. This leads to stuffy, uncomfortable air, that can be unfiltered and stagnant. Many homes with finished basements are absent or limited on returns.
This causes colder, more damp conditions in the basement, and often makes it more difficult to properly cool the rest of the house in the hot summer months. Adding a return in the basement can often be a very simple fix that has a noticeable impact on a home’s comfort.
If we continue down the line of the return to the return drop to the left or right of the furnace, we often find that existing returns are not sized properly for newer, let alone existing, HVAC systems. If the return drop is too big; the system will not be able to produce the correct pressure to be able to suck the air required to properly condition the air. If the return is too small, the pressure will be too high, causing the system to have to work too hard. This wears down components and often doesn’t give the correct volume of air for the system to work efficiently or produce the desired results. This is a critical step that is often missed.
The return boot of existing systems is also not ideal for newer systems. Newer age blowers (ECM or Variable Speed) are much more efficient, but far less durable than motors of the past, called Permanent Split Capacitor Motors (PSC). If airflow isn’t correct, these blowers won’t work as well, causing them to be unproductive, inefficient, and can cause damage or failure.
Our heating installation and cooling installation team at Summit has worked with Manufacturer’s Field Technical Consultants (FTC’s) to not only design Summit’s installation practices, but also custom designed sheet metal, including the “Summit Boot”. This radius turned boot has a radius heel that softly guides the air through the turn from the drop into the furnace filter and cabinet. Within the design of the boot, we also have 3 or 4 turning veins inside of the boot to more evenly distribute the air through this cavity. This allows for even airflow across the entire surface of the filter.
In almost all applications, we install a 5” air filter sealed cabinet and filter. This filter allows the correct volume of air to the furnace at the correct pressure. The calculation for proper airflow across a filter is square inches times 2 for a 1 inch filter and times 4 for a 5 inch filter. A 2.5 ton system can take a 1” filter because 20×25=500 sq in times 2= 1000 CFM. For correct airflow you need to deliver 400 CFM per ton. Therefore, 1000/400 = 2.5 tons. This equation shows that no system 3 tons or larger should have a 1” filter. That is the reason that Summit uses 5” filters on almost all the systems we install.
The next consideration with airflow is with the return pedestal. In almost all manufacturer’s installation instructions it states that a return pedestal is recommended to be installed when in the upflow orientation. This is especially true for 90% applications. A little backstory. Manufacturers used to make furnaces 50” tall, sometimes taller. They knew the importance of airflow in the blower cabinet.
That measure moved to 40” to accommodate Evaporator coils in shorter basements, with little affect to airflow. This was further adjusted in the 90’s to reduce transportation costs because (3) 33-inch furnaces can be stacked in a 10-foot-tall truck. The issue with this was discovered 10 years or so later when secondary heat exchangers began to crack and need replacement.
Warranty horror stories aside, instead of adding the 6 inches of blower cabinet space back onto the furnace, the recommendation was for contractors to build a sheet metal return air pedestal to go underneath the furnace and provide the necessary space for proper air flow.
Some manufacturers have now started building and selling these as accessories. All manufacturers recommend it for most if not all furnaces, and many require them to keep the warranty on certain sizes or any 90% application. Most HVAC installing contractors have ignored this recommendation to the demise of many heat exchangers and homeowners’ pocketbooks.
THE REFRIGERANT CYCLE
The refrigerant cycle in a HVAC system is the closest thing we have to real magic. We move air through your home, across an evaporator coil where heat is absorbed through metal, turned into a gas, then turned into liquid. It is then pulled through a metal tube, outside to a condenser coil, beside a fan that blows outside air past the coil, cooling the liquid down, then compresses the liquid back down to a gas, and sends it back inside to do it all over again.
WHAT? How does that work? In truth, it is all basic science, but for that science to work correctly, we cannot introduce any additional variables or containments. These systems must remain hermetically sealed so they don’t introduce anything into the system, especially moisture; oil and water don’t like each other. It is vital to make sure that the line is clean from contaminants like soot from brazing.
To prevent this, we use the best practice of brazing with nitrogen. This is readily available inert gas that puts pressure on the line, forcing any potential contaminants to rest outside of the copper line set. It’s an easy task, but not often actually done in our industry. It is vital to prevent leaks which could allow moisture into the system. To prevent this, we pressure check the sealed system with nitrogen and let it rest. If there are leaks, you can hear them, and the pressure won’t hold.
Once this is complete, we triple evacuate the system changing the atmospheric pressure inside of the line to cook off any containments or moisture. We do this 3 times to increasing levels of pressure called microns, setting up 3 different levels of stabilization. If there are any leaks, you cannot pull a vacuum this high. Once proven stable, we release the charge and properly balance the system. As we are charging the system, we are testing and balancing it. We dial in the air flow to manufacturers best practices standard.
We check for proper airflow, static pressure, and CFM. We also test fire the furnace and make sure the firing rate is correct and that the furnace is creating the proper amount of heat considering the variables in your home including the incoming gas pressure, differences in ductwork, open registers, and do you have a dog that’s favorite spot is on a floor return! Airflow is the largest factor in a systems comfort, efficiency, and reliability.
The Summit Installation team goes a step beyond at every chance we can. Once the system is installed, and your system has been checked over by your installation team, most companies are done, unless there are issues. We are not.
A manufacturer’s specifications are determined by design parameters. Say 72 degrees in the home at 55% humidity. With current refrigerants, being off by ounces is detrimental to a system’s capacity and efficiency. If we are off by a few ounces of refrigerant, the system won’t be as efficient or be able to cool as well as its supposed to be, keeping in mind that there are on average 8 pounds of refrigerant in a system. So being 2% off is a big deal. It is not possible to be within 2% on a 95-degree day with 80% humidity in the home.
So, we let the home stabilize for 24 to 48 hours and we come back. We have a specially trained technician that we call a commissioner who comes back to your home, checks the work, and makes sure that the airflow, static pressure, and refrigerant charge are all correct. This ensures that your system is running as the manufacturer intended.
If you are in the Kansas City area, we would love to help you. If not, we hope you will find these guidelines helpful in locating a contractor that adheres to best practices. At least you should have a better knowledge of what to look for and why these things matter.
The team at Summit Heating and Cooling is trained to perform our duties at the industry best standard. We pride ourselves in being part of industry innovation, and we push the boundaries of the industry to seek out and adopt better practices to serve our customers. High quality and best practices are a moving target, but unmistakable. The Summit Team looks for opportunities to improve every chance we get.
That way you know that when you become a client of Summit Heating and Cooling, you will be in the best, most trustworthy hands with our mutual goal of the best possible indoor comfort for you and your home. If you have been searching for a top-quality HVAC provider, you’ve found us. If you have someone ask who you use, you can tell them “If you’re looking for the top, REACH for the Summit”