Top 10 Fan Coil FAQ’s

1. A fan coil is among the easiest units to understand in the HVAC industry.  Basically, there is a small forward curved fan, a coil, and sometimes a filter.  They are all direct drive units. Click HERE to see Capital Coil’s full Fan Coil Product Lineup.

2.  Fan coils run from 200 CFM to 2200 CFM, which is 0.5 ton through 5.5 tons.  Anything larger than these sizes requires a belt drive unit…which is really a full fledged air handler.

3.  The thing that differentiates fan coil units is where and how they are going to be installed.  Is the unit going to be hidden above the ceiling or maybe in a closet?  Or is it going to be exposed so that everyone can see it?  Will it be ducted or will it just pull air from the space where it’s located?  These are things that determine the configuration of the unit and which style of unit to choose.  But, every unit has 3 things in common:  fan, coil, and sometimes a filter.

Fan Coil 4.  Some units have (2) coils.  One for heating and one for cooling.  Obviously, there is a separate supply and return connection for each coil and these units are known as 4 pipe fan coils.  Many units only use the same coil for both heating and cooling and these units are 2 pipe fan coils.

5.  Units are either horizontal or vertical depending on the orientation and flow of the air.  A typical fan coil in a hotel room is a vertical unit with a mixture of air coming from outside and the air recirculating in the room.  The air enters at the bottom of the unit and is drawn upward through the fan.  This makes the unit a vertical style.  Many units are horizontal with the air entering at the back of the unit and traveling horizontally through the unit.

6.  Almost all fan coils are 3 speed or infinite speed settings based on the controls.  The high speed gives you more BTU’s, but more noise too.  Because the unit is direct drive, when you dial down the speed, you also dial down the performance.

7.  Coils in the units tend to be 3 or 4 row deep coils.  3 row is typically used the most, but if you need the extra performance, 4 row is the way to go.  Performance is always governed by the cooling aspect.

8.  Fan coils sometimes have short runs of duct work and there is static pressure on the unit.  Static pressure reduces the amount of CFM and BTU’s that the fan coil can give you.  This is true of both horizontal and vertical units.  Most performances listed on charts that you will see are static free performances.

9.  The control systems for fan coils are often more complicated and more expensive than the units themselves.  There are balancing valves, isolation valves, unions, y-strainers, p/t plugs, air vents, ball valves, thermostats, condensate float switches, and disconnects.  Capital Coil & Air can do this at the plant, but it is much cheaper and easier to do it at the installation. 

10.  Just describe your installation requirements to a sales engineer at Capital Coil & Air and they will guide you to the right design and configuration of the unit for you.  It requires only a phone call or e-mail! We look forward to working with you!

 

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What Is Meant By A “Bank” Of Chilled Water Coils

For those that work with HVAC installations on a regular basis, you have run across the problem of needing to install new chilled water coils in very tight, confined areas. The coil is too big to fit in the Chilled Water Coilselevator, and/or the HVAC room is so small that you are likely to damage the coil simply by moving it. As a solution to this challenge, chilled water coils are often installed in “banks” of coils. You are most likely to see this configuration in Air Handler Units, as well as “built-up” systems. Due to face velocity limitations across the coil, you will need larger coils in order to meet your required face area. With this in mind, there are a few specific reasons why you want to avoid having a single, large coil in one of your units.  Starting with the obvious: larger coils are much more difficult to transfer and install. This is especially true for older buildings, where the rooms were essentially built around the HVAC system.

As you’ve probably experienced, some of these areas can barely fit a single person, so installation – if even possible – is a logistical nightmare. Also, the larger the coil, the easier it is to damage during transport to the jobsite. To avoid these issues, simply break down the single, larger coil into smaller coils. When piped together, those smaller coils are stacked into “banks” of coils in the system. If installed correctly, this “bank” should have the same performance as the larger, single coil.

Casing

There are many different casing options available, but “stackable” flanges are required for heavy chilled water coils that are “banked”. The flanges are often inverted inward and down to give added strength to the casing, which is needed due to the fact that another coil of equal weight will be stacked on top of it. When ordering coils in a “bank” configuration, be sure to let the manufacturer know that they will be “stacked”.

Many engineers also use stainless steel casings on chilled water coils. While more expensive than traditional galvanized steel, stainless steel protects against excessively wet coils and/or corrosive elements in the airstream. Keep in mind that the majority of coils fail because of old age and its casing, as opposed to failure with the coil’s core. With that in mind, doesn’t it make sense to select heavy-duty stainless steel casings that are more durable and meant for stackable installations?

Drain Pans & Water Carryover

Water Coils

All chilled water coils must be sized so that the face velocity across the coil does not exceed 550 ft/minute. Water on the outside of the coil is carried away from the coil’s leaving air side in an arc, while water in the highest point of the coil is carried further down the unit or ductwork. “Stackable” coils often require intermediate drain pans under each coil to catch the excess water carryover. Each coil in a bank requires its own drain pan, as a single, large pan under the bottom coil is not enough.

Circuiting/GPM

If all of the coils in a “bank” are of equal size and handling the same CFM, then the GPM of each coil will also be the same.

Always feed the bottom connection on the supply header on the leaving air side of the coil. This ensures counter air and water flow. This also prevents the coil from short circuiting because the header fills first and circuits all of the tubes equally.

Designing Banks Of Coils

Almost all coil “banks” perform more efficiently if you design something more square in shape, as opposed to long and/or high. In a “bank” of coils, you may find that one coil has points of 300 ft/minute, with other points at 800 ft/minute. Scenarios such as this will cause water-carryover! You generally want to be as close to 550 ft/minute as possible in order to allow equal airflow distribution across the face area of the coil.

Anytime you are designing and/or building coils, work closely with the manufacturer as an added resource to ensure that you are getting the ideal solution for your HVAC system. Capital Coil & Air works on similar jobs such as these daily, and we welcome the opportunity to work with you in whatever capacity is needed.

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Now Offering R-454B Refrigerant for All DX Coils

In keeping with most of the OEM’s in 2025, Capital Coil is helping everyone transition from R-410A over to R-454B refrigerant in their DX Coils. Whether you are designing a new system, or retrofitting an existing one with a condensing system, Capital Coil can help in making the switch in refrigerants.DX Coils

If you are not yet aware, the EPA is working hand in hand with many of the major OEM’s to help reduce commercial HVAC’s carbon footprint. One of the major ways in which HVAC manufacturers are helping and complying with the new industry standards is the gradual change in refrigerants from R-410A to R-454B. Beginning in January, 2025, no new system is allowed to be built or imported using the older refrigerants. Without going into a deep dive on the differences, R-454B offers a lower GWP (global warming potential) alternative to R-410A. Hence the mandate to change to that refrigerant type. 

However, Capital Coil will still offer R-22 and R-410A for DX Coils in older systems that might not be compatible with R-454B. In other words, Capital Coil has been, and will remain, the most reliable source for all commercial and OEM replacement coils. Our #1 job is to make to your job easier, so please reach out. You will be glad you did.

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Case Study: We Need These Coils on a (5) Day Quick-ship

In late June, Capital Coil received a call from a Trane office in Ohio regarding quick-ship availability. One of Trane’s top customers had an urgent need for (12) large chilled water coils with stainless steel casing. The problem/hurdle that they were encountering was that they needed all (12) coils to be built and ship out of the factory in (5) business days. Completion of the whole project was 100% contingent on them receiving the coils in their specified time-frame. An additional complication was the fact that July 4th was the following week, and they needed to have the coils ship prior to the holiday.

Trane shopped the project around to different manufacturers, but not one could guarantee to ship in (5) days. Some manufacturers waffled and claimed that they could have them built in (6) or (7) days, but not one could guarantee to ship in (5) days. A sales rep in that same Trane office, who had worked with Capital Coil previously, suggested that his co-worker reach out to us to see what we could do. After speaking with Trane’s project manager, we immediately contacted our head of production to make sure that we had the capacity to complete all (12) coils in the required (5) days. She assured us that we had the materials and manpower on-hand to get them all built and ship on time. We agreed to accept the project and began work on the coils immediately.

Due to the size of the project, as well as it’s time-sensitivity, we had multiple calls daily with our factory to ensure that everything was proceeding on schedule. We then gave Trane daily status updates, so they were constantly informed of everything from the brazing of the coils to entering the final testing phase. Chilled Water Coil

As promised, all (12) coils were built correctly and shipped out in the required (5) days. Our logistics team was then in constant communication with the freight company to make sure that the delivery was on schedule. And just like during the production phase, we passed daily tracking updates along to Trane, so they knew where their coils were at all times and when they could expect delivery. All (12) chilled water coils arrived on July 3rd with zero freight damage, and the project was completed on time!

A company as large and influential as Trane can have their coils built by anyone, but Capital Coil was the only manufacturer that could guarantee to have their coils built and shipped by a required date. Additionally, in working so closely with Trane throughout the whole process, they were kept up-to-date in real time from the start of production to final delivery.

Capital Coil offers a level of service that you won’t get with other manufacturers. When we guarantee to ship by a certain date, we stand by that guarantee, or you do not pay!

 

Trane’s project manager’s comments to Capital Coil upon completion/delivery:

“This will help us get a jump on this project prior to the big event taking place next week! 

I will make sure to share your information with others across our great lakes region about our experience with your company, so that they know we have THIS option to go to for our coil needs. THANK YOU ALL!!”

5 Work Day Quick-Ships on HVAC Coils – Why Capital Coil does it right

Day 1 – 38% of all orders sent to Capital Coil are on some kind of quick-ship, whether it be on a (5 day, 10 day, or 15 day). We enter the order immediately so that all departments in the plant have the project in their systems and are ready to move on it right away. The coil isQuick-Ships engineered, routing sheets are sent to the shop floor, and everybody now knows what needs to be built. 

Day 2 – Sheet metal casings are cut and sized, headers and connections are fabricated, while tube sheets are fabricated.

Day 3 – All tubing and fins are cut, stamped and assembly begins. You can see what the coil will look like upon final assembly at this point. Coils can be seen sitting on assembly tables.

Day 4 – Tubes are then expanded into the fins, and keep in mind that this is not a short process. Headers are then brazed to the tubes, and if there are return bends, they are connected. The coil is completely assembled and moved to the testing tank. The coil is tested under water for 20 minutes at 550 PSI. About 3% of coils have small leaks someplace in the brazing and are sent back to braze again.

Day 5 – The coil is crated and sent to shipping for routing to the customer. Then most importantly, your coil will be shipping in the guaranteed (5) days.

As you can see by this description, with quick-ships, there is not a lot of room for error in the timing and shipping with OEM HVAC replacement coils. We’ve been doing this for a while now, and we’ve had an approximately (97%) success rate fulfilling all quick-ship requests. We offer quick shipments 365 days per year, with both (10) day shipments & (15) day shipments also available for lower premiums.

diagram 

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Fan/Coil Units Without the Mysteries

Lots of companies in the HVAC business attempt to keep their products as complicated as possible in order to lend a certain “mystery” to the industry, which has never made sense to us at Capital Coil. We have all been in this information age for quite some time with more information/data available to more people than ever before. We feel that by removing some of the “secrecies” surrounding fan/coil units, our customers will be able to better understand the products as we do.

Most of our potential customers know Capital Coil strictly for our HVAC coils, which makes sense because the word “coil” is in our company’s name. But some people may not be aware that we do in fact offer multiple fan/coil models with various quick-ship options, or that fan/coils comprise a significant portion of Capital Coil’s overall business.

With that said – what are fan/coil units (FCU’s) exactly?fan/coil units

  • Fan/coils are easy to understand when you remove a lot of the complex terminology. Our definition of a FCU unit is one that is direct drive and not belt driven…easy enough to understand, right? There is a fan, a coil, and sometimes a filter. Capital Coil offers numerous model types, but the only thing that really differentiates the various models from each other is the casing on the outside of the unit. And the casing is typically based on how and where you want to install the unit.
  • The fan is directly mounted on the motor, and the maximum CFM that can be used in these units is typically 1,200 FT/min. However, Capital Coil does offer some units that can have a CFM as high as 3,000 FT/min, or (7.5) tons.
  • FCU’s can be divided into two groups based on airflow – Horizontal and Vertical. Think of fan/coils installed in a hotel or classroom. These are typically vertical units because the air goes from the bottom of the unit to the top discharge airflow.  Horizontal units have horizontal airflow with inlet and discharge both horizontal as well.
  • As mentioned, fan/coil casings are determined based on how and where you want to install the unit. But figuring that out involves asking some additional questions, such as is the unit hidden above the ceiling or is it exposed? Is the unit horizontal or vertical? Does the unit need a filter?
  • Like most any product, there are several “packages” that you can select, such as certain valves, that will make the unit more expensive and complex. But once you strip away the complex terminology and are able to understand the basic design and concept of FCU’s, they are pretty easy to work with.

Now you know that Capital Coil is very much in the fan/coil business, and when you are looking for something fast, Capital Coil should be your first call or email!

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Why are quick-ships so important??

Christmas season is in full-swing, and your current coil supplier has suspended all Quick-Ships with little to zero notice to its customers. Does that sound familiar these days? Additionally, the clock is ticking to complete those projects that need to be done by the end of the year. In this industry, this scenario is when “Quick-Ship” availability is an absolute must. Right now, the vast majority of coil manufacturers are scrambling to complete standard orders on regular lead-times, and if by dumb-luck they are able to temporarily offer any type of expedited build, the added premiums are so astronomical that very few customers can afford to use those options.

If you need a new coil, your first inclination will probably be to call the OEM. But more times than not, they are not flexible or nimble enough to handle your emergency within an acceptable time-frame. Quick-ships are generally based on emergency conditions, and that is precisely the worst time to discover that your regular supplier has suspended Quick-Ships.

So why do so many manufacturers seem to get so overwhelmed at various point every year? In short, many manufacturers take on a glut of OEM business, or other large projects with small profit margins. In many cases they do this simply to keep the factory running during the slower periods of the year. This has the effect of delaying standard lead times, and in many cases, cancelling Quick-Ships altogether. It is very hard to do business with companies that make themselves unavailable when you need them the most.

Capital Coil’s primary duty as the leading OEM replacement coil manufacturer is to fill in those gaps and work with you to help alleviate any emergencies. Whether you need a coil in (3) weeks, or (5) days, Capital Coil has got you covered.

Capital Coil does not try to be all things to all customers, and we’re most comfortable “staying in our lane”. Our #1 goal is to ensure that we have multiple quick-ship options open all year around…even if that means turning away an order to ensure sure that our Quick-Ships are ALWAYS available!!  Quick-ships

Because Quick-Ships make up such a substantial portion of our overall business, Capital Coil has hit 99.9% of our quick-ship requests over the last (2) years. An unfortunate forklift mistake makes up the other .1%. Throughout the first 6 months of 2022, approximately 80% of all orders were/are quick-ships, and they have either all been completed on time, or are 100% on schedule.

An RFQ that sits on a desk unanswered is useless to everyone involved. If you need a quote, you’ll have your price and any required submittals that same day. It really is that simple and easy! Working with Capital Coil will remove many, if not all of the annoying and unannounced shut-downs that come with other manufacturers, so please let us help you when you need it the most!

 

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