Direct Expansion & Chilled Water Cabinet Coils

There are lots of ducted cooling applications with chilled water and/or DX (Evaporator) coils where you need to add incremental cooling to an existing system. However, there is an important difference when using heating coils. Because it’s a Cabinet Coilheating coil, there is no humidification occurring or water/condensate to draw. Due to these factors, cooling coils require a little more creativity and labor to install.

At Capital Coil & Air, we have removed all of the guesswork out of the application. Capital Coil manufactures Custom Coil Cabinet sections from as small as 12” x 12” sections to as large as 54” x 90” sections. We manufacture these units in both Chilled Water and DX (Expansion), as well as in 1/2” & 5/8” copper tube coils. You have the option to select anything from (3) rows to (8) rows. Additionally, we will custom-design the Cabinet around whichever site you select. Cabinet units include both insulation & drain pans, while the supports and casing allow you to connect directly to the ductwork. We can also add a Heating Coil inside the unit for more dehumidification if needed. Cabinet Coils are perfect for either heavy or light-duty installations.

All Cabinet Coils are available on Capital Coil’s Quick-Ship Program as well. As you are probably all-too-familiar, trying to custom design coils in the field is a pain. Using Cabinet Coils will greatly ease the whole installation process. Please see our Insulated Cabinet Coil Brochure for more details on available custom sizes.

Capital Coil & Air looks forward to the chance to your coil replacement specialists. Please give us a try on your next project!

RELATED POSTS

Chilled Water Coils & Moisture Carryover

New Product Offering: Insulated Cabinet Coils

Top 10 Chilled Water Coil Facts


Differences Between Commercial & Industrial Coils??

The best performance you can get out of commercial coils is with copper tubes/aluminum fins. An extremely important fact to take into account is that when you change the materials of construction to an industrial coil, there’s always a drastic change in the performance. 

The explanation is really quite simple: when we build a stainless steel or 90/10 cupro-nickel coil, the materials don’t match up in terms of heat transfer to copper tubes/aluminum fins. So what does that mean? Using a chilled water coil as an example – you have a (4) row chilled water coil with copper tubes/aluminum fins, and you want to change to stainless steel. You will need to move to an (8) row coil to meet that same performance.                                                                                                                                                                          Commercial Coils

What conditions require these types of materials? The most common is with high pressure applications. Anything above 200 psig requires that you change construction materials from copper tube/aluminum fin to a special material that is able to work better under those conditions. The other instances are when you’re dealing with high temperatures or corrosive atmospheres. 

Capital Coil & Air manufactures and designs a wide assortment of heavy-duty industrial coils to withstand the environment of industrial applications.  Standard and custom designs are available for new and retrofit installations.  Our industrial coils are manufactured from quality materials that are heavier grades and thicknesses.  This ensures dependable performance and longevity, even under the most demanding conditions. While most manufacturers throw out astronomical prices or lead times that can better be explained as “months” rather than weeks, Capital Coil’s lead times are (4-5) weeks for cupro-nickel and (5) weeks for stainless steel.  

Whether it’s for boiler air preheating, pulp and paper drying process, lumber drying process, textile drying process, chemical heating process, Capital Coil & Air provides high quality industrial coils designed for easy maintenance and low operating costs.  With capabilities to build fluid coils for water, glycol, oil, and other liquids as well as refrigerant coils and steam coils for high pressures, we can easily meet all of your industrial coil requirements!

RELATED POSTS

Coil Costs: What Will Make Your HVAC Coils More Expensive?

Why are HVAC Coils Copper Tube and Aluminum Fin?

Top 5 Reasons Commercial HVAC Coils Prematurely Fail


Coil Costs: What Will Make Your HVAC Coils More Expensive?

We get questions all the time about how we build our HVAC coils, and what will add costs and what will not. This post will address the many inaccuracies other “mass production” manufacturers Hot Water Coilshave put out there. It’s very simple. There are only three areas on a coil that will add costs: the casing, the tubing, and the fins. Now we’ll deal with the many inaccuracies that most manufacturers try and “upsell” to you.

  • Connection sizes: There should be no additional cost switching from a 2” MPT connection to a 3” MPT connection. Only on rare cases with a 4” or 5” connection, should you ever see an adder in price.
  • Pitching the casing in a steam coil: All steam coils should be pitched. There is not some mysterious adder you need to pay to have you coil built the right way.
  • Casing depth and dimensions: Whether you want your coil 4” deep or 8“ deep, or want a 2” flange instead of a 1” flange, there should be no cost associated with simply more sheet metal.
  • Distributors on a DX Coil. This is our favorite. We actually had a call from a contractor who asked how much extra it was to get a distributor on his DX Coil. Distributors come standard with DX coils!
  • Flanges for “stackable” coils. This is just standard practice to meet the needs of your customer.

Coil Casing Adders: Most HVAC coils we manufacture are built with 16 ga. galvanized steel casing. We offer 3 other options that are slightly more expensive, but it all depends on your application if any of them are actually needed. Stainless steel casings are used in a corrosive atmosphere and are the most expensive option (even then, it’s only 10-15% more). 14 ga. galvanized steel casings are used primarily in coil banks where you might have between 2-4 coils stacked on one another. This adder for 14 ga. casing is only roughly 2-3% per coil.

Tubing Adders: There are many materials options in tubing and we offer all of them. Whether you need stainless steel, carbon steel, cupro-nickel, or standard copper tubes, we can build exactly what you need. Like any product, the more unusual the material, the more expensive the cost is. For most jobs with just copper tubes, adding a thicker tube wall will add only 10-15% in cost to the job and could double the life of your coil. For just a couple hundred dollars, that coil that would last 10 years could last 20. Some applications, like high pressure steam coils, require a thicker tube wall or more durable material or the life span of that coil will be extremely short. You’d be surprised at how many other manufacturers’ coils we’re asked to rebuild with the correct materials.

Fin Adders: Most coils are offered with aluminum fins with a thickness of .006”. The adders to go up in fin thickness are not much, but always remember, the thicker the fin, the more air pressure drop it’s going to add to your coil. The most costly adder you can do to a coil is adding copper fins. It will double the cost of your coil, and in some cases, be 2.5 to 3 times more expensive. This wasn’t the case 20 years ago, but the price of copper has risen over the last few years. We usually recommend coating your coils instead. It’s far more economical and only adds a week to the lead time.

Capital Coil & Air understands that people do business with you like and who you trust. Coil manufacturers should be an open book with this information. Unfortunately, most try and prey on what you don’t know. Hopefully, this helps with any confusion. Capital Coil & Air looks forward to working with you!

RELATED POSTS

Four Things That You Need When Buying Replacement Coils

10 Things You Need to Know to Buy Replacement Coils Effectively

The Smart Approach to Buying HVAC Coils (and Saving Money)


Construction Vs Performance: Need To Know Terminology

If you have ever dealt with commercial HVAC coils, you have probably come across numerous “industry terms” with little to no explanation as to what these terms actually mean. To further confuse you, some verbiage is specific to the actual construction of the coil, while others are only important when determining a coil’s performance. If you do not work with coils on a frequent basis, it is hard to decipher what exactly these terms are referring to. To help translate this industry verbiage, Capital Coil & Air has come up with a list/glossary of the most common and relevant terms that you are likely to come across on most coil jobs.

 Performance

  • AHRI (Air-Conditioning, Heating, and Refrigeration Institute): Developed industry standards for air conditioning, heating, and commercial refrigeration equipment. All of CCA’s coils are AHRI-certified, so you know you’re getting dependable quality and performance in every product.
  • Air Pressure Drop: Air Pressure Drop is a result of Flow Rate, Fin Type, Rows and Fins per Inch. In addition, on either Chilled Water or DX (Evaporator) Coils, the air pressure drop is affected by the condensate on the fin surface.
  • Airflow (CFM): Cubic Feet per Minute, which refers to the amount of air flowing across the coil. A typical cooling coil should produce between 400-500 FPM. You want to avoid exceeding 550 FPM on all Chilled Water & DX Coils. Too little airflow means your coil is not running at peak capacity, while too much airflow can result in excess water carryover.
  • Entering Air Dry Bulb Temperature: You guessed it! The sensible temperature of the air entering the coil.
  • Leaving Air Dry Bulb Temperature: The sensible temperature of the air leaving the coil. Why does this matter? If you are trying to replace and duplicate a coil’s performance, making sure that your new coil can meet or exceed the old coil’s leaving air temperature is a crucial factor.
  • Entering Air Wet Bulb Temperature: This temperature signifies the amount of moisture in the air entering the coil.
  • Leaving Air Wet Bulb Temperature: Conversely, this temperature refers to the amount of moisture in the air exiting the coil.
  • Total Capacity: The sum total of a coil’s sensible and latent capacities.
  • Steam Pressure: Only relevant to steam coils, the saturated steam pressure at the inlet of a steam coil. Steam pressure is usually relative to the steam coil’s total capacity.
  • Steam Condensate: Again, applies only to steam coils and is a measure of the condensate generated by that steam coil.

Construction

  • Casing Type: The supporting metal structure for tubes and the header. Different casing options include Flanged (standard), Slip & Drive, Inverted, Stackable, and Collared End Plates & End Plates only. Steam Coils require Pitched Casing to allow for adequate condensation drainage.
  • Casing Material: The coil’s casing can be made from a variety of different materials. Options include: 14 or 16 Gauge, Galvanized Steel; 304 or 316 Stainless Steel; Copper & Aluminum. Please contact us directly to see about options other than those listed.
  • Connection Material And Type: Standard connection types are MPT (Male Pipe Thread, threaded on the outside), FPT (Female Pipe Thread, threaded on the inside), ODS (Sweat Connections, no threads)
    • Water & Steam Coils: Copper MPT, FPT, (with options for steel MPT & FPT)
    • DX & Condenser Coils: Copper ODS normally
  • Circuiting/FeedsCircuiting is determined by the number of tubes in each row divided by the total number of tubes fed (or feeds). Feeds are also known as the number of parallel circuits in the coils. Always feel free to call Capital Coil’s sales department with any circuiting-related questions.
    • Water Coil: Enter the coil’s performance data into CCA’s coil selection program, and select the “auto” sizing option to determine the optimal number of feeds.
    • Condenser Coil: Since the condenser is a rating program only, the user must enter a value for the number of feeds. A good rule of thumb is to have approximately 8 – 15 psi refrigerant pressure drop in the condenser.
    • DX Coil: Enter coil’s performance data into CCA’s coil selection program, and select the “auto” sizing option to determine the optimal number of feeds.
    • Steam: Always a full or double circuit
  • Fin Height: FH is measured in the direction of the fins, or perpendicular to the direction of the tubes.Water Coil
    • For 5/8″ tube coils, fin heights are available in increments of 1.5”
    • For 1/2″ tube coils, fin heights are available in increments of 1.25”
    • For 3/8″ tube coils fins are available in 1.00″ increments
  • Fin Length: FL is always measured in the direction of the tubes, regardless of which direction the tubes are running.
  • Fins per Inch: Represents the fin spacing on the coil. The number of fins per inch is an essential component when ordering a replacement. Using a standard ruler, simply count the number of fins per inch on the coil.
  • Number of Rows: Rows represent the coil depth and are always counted in the direction of the air flow, regardless of how the coil is mounted. Count the number of rows by viewing the header end or the return bend end of the coil.
  • Hand (Left or Right): A coil’s hand is determined by the direction of the airflow. Look at the finned area of the coil, and if the air is hitting you in the back of the head, look to see which side of the coil the headers are located. If the header(s) are located on the right side, then the coil is right-handed. Likewise, if the header(s) is located on the left side, it is left-handed. An important point to remember is that you always want the airflow to run counter to fluids, refrigerant and steam flow.

Miscellaneous

  • Laminar Flow: Tends to occur at lower fluid velocities, below a threshold at which it becomes turbulent. In other words, laminar flow is smooth while turbulent flow is rough. Greater heat transfer occurs in a coil with turbulent flow as opposed to a calm, laminar flow.
  • Dry Weight: The estimated weight of the coil; not counting internal fluids or packaging.

RELATED POSTS

Tips on Hand Designation & Counter-flow

Coils and Counter-flow: 5 Common Questions

You should never have to worry about performance on replacement coils. Well…almost never!