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Refrigeration Technicians Best Tools

Refrigeration

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October 8, 2023

Essential Tools for Every Refrigeration Technician: A Comprehensive Review

Are you intrigued by the inner workings of refrigeration systems and the vital role they play in our everyday lives? Whether you’re an aspiring refrigeration technician or a seasoned pro, understanding the tools of the trade is essential.

In this comprehensive review, we delve into the top tools that every refrigeration mechanic should have in their arsenal. These tools are not mere conveniences; they are the very instruments that empower technicians to diagnose, repair, and maintain refrigeration systems efficiently and effectively.

1. Manifold Gauge Set: Refrigeration mechanics rely on manifold gauge sets to simultaneously measure high and low side pressures in refrigeration systems. These sets are like the eyes of the technician, providing critical insights into the system’s condition. By providing real-time data, refrigerant gauges are essential for diagnosing issues and ensuring optimal system performance.

List of Gauge Manifolds

1- Shikha 5 Foot (see image)

2- Fieldpiece SM380V

3- Testo 550’s

4- Lichamp Gauge Set

5- Yellow Jacket 42004

2. Vacuum Pump: A vacuum pump may seem unassuming, but its role is monumental. It evacuates air and moisture from refrigeration systems before the introduction of refrigerant, ensuring that the system operates efficiently without unwanted contaminants.

List of Vacuum Pumps

1- Xtremepower 3 CFM 1/4 HP (see image)

2- VIVOHOME 4 CFM 1/3 HP

3- Fieldpiece 6 CFM 1/2 HP

4 – Robinair 3 CFM 1/4 HP

5- OMT 4.5 CFM 1/3 HP

3. Leak Detection Tools: Finding elusive refrigerant leaks is a challenge without the right tools. Leak detection tools, including electronic detectors and bubble solutions, play a crucial role in environmental protection and system efficiency by pinpointing these leaks.

List of Leak Detectors

1- Elitech ILD-200 Infrared (see image)

2- Aprvtio ALD-200 Halogen

3- Inficon 705-202-G1

4- Fieldpiece DR82

5- Xetron CLD-100

4. Digital Multimeter: An HVACR technician’s electrical diagnostic prowess relies heavily on a digital multimeter. This tool measures voltage, current, and resistance in electrical components, making it indispensable for troubleshooting electrical issues.

List of Digital Multimeters

1- KAIWEETS Digital Multimeter (see image)

2- AstroAI TRMS 6000

3- AstroAI 4000

4- Astro 2000

5- Klein MM325

5. Pipe Cutters and Flaring Tools: Copper pipes are the lifeblood of many refrigeration systems, and pipe cutters and flaring tools ensure these essential components are accurately cut and shaped for the job.

List of Flaring Tools

1- Super Stars 1/4″ to 3/4″

2- Flexzion 3/16″ to 3/4″

3- Libraton 1/4″ to 3/4″

4- Rigid 41162 377 3/16″ to 3/4″

5- HAUTMEC 3/16″ to 3/4″

6. Pipe Benders: The importance of smooth, kink-free bends in copper pipes cannot be overstated. Pipe benders are the secret to achieving these precise bends without compromising the integrity of the pipe.

7. Thermometers and Thermocouples: When it comes to temperature measurement, accuracy is key. Thermometers and thermocouples help technicians monitor temperatures at various points in the system, assisting in both diagnostics and cooling optimization.

8. Tubing Tools: Properly preparing tubing for installation is a fundamental step in any refrigeration project. Tubing tools, such as deburrers and reamers, ensure that tubing is ready for action.

9. Hex Key Set: Hexagonal screws and bolts are commonplace in refrigeration systems. A set of hex keys is a technician’s trusty companion for swiftly disassembling and reassembling components.

10. Oil Pump and Oil Injector: Lubricating oil is the lifeblood of compressors. Oil pumps and injectors ensure that the compressor functions optimally by delivering the right amount of lubrication.

11. Torque Wrench: Precision matters in refrigeration systems. Torque wrenches guarantee that bolts and nuts are tightened to precise specifications, safeguarding components and maintaining proper seals.

12. Digital Scale: In the intricate world of refrigeration, precision is paramount. This is where a digital scale steps in as a silent but indispensable partner for refrigeration mechanics. Why? Because refrigerants, lubricants, and various chemicals must be added to systems with meticulous accuracy.

A digital scale ensures that the right quantities are added, helping maintain the system’s efficiency, performance, and, perhaps most importantly, the environment. It’s not just about getting the job done; it’s about getting it done right, and that’s where the digital scale shines. So, let’s weigh in on the importance of this often-overlooked tool in the refrigeration technician’s toolkit.

List of Digital Scales

1- Eiltech LMC-200A (see image)

2- Xetron High Accuracy

3- Eiltech LMC-300A

4- Yellow Jacket 68862

5- VIVOHOME Precision Electronic

These tools are the cornerstone of any refrigeration technician’s toolkit. Stay tuned as we dive deeper into each of these essential instruments, unveiling the art and science behind their usage, and why they’re indispensable for refrigeration technicians around the globe.

Air Filters vs COVID-19

MEP Academy Instructor

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September 4, 2023

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In this article we’ll answer a question that we get all the time. What filter, if any, can filter out the SARS-CoV-2 virus which leads to COVID-19, the disease? We’ll show you how efficient the different air filters are at filtering out various items for asthma and allergy sufferers, and the virus that leads to COVID-19.

If you prefer to watch the Video of this presentation, then scroll to the bottom or click on the following link. Air Filters vs COVID-19

The ability of an air filter to remove microorganism, dust, pollen, dust mites, mold spores, pet dander, bacteria and viruses is indicated by a numerical value. This number, which is indicated as a MERV rating, states the filter’s efficiency at removing various sizes of these items. We’ll show you which filters, if any, work the best to protect you from these potentially harmful organisms.

MERV Rating

Minimum Efficiency Reporting Values, or MERVs, indicate the filter’s ability to capture larger particles, those 0.3 microns and larger. The higher the numerical rating, the greater the air filter is at removing particles from the air stream. A MERV-13 is better than a MERV-11 filter at removing particles, but how good are they against bacteria and a very small virus that leads to COVID-19.

Virus and Bacteria Removal

According to ASHRAE, research has shown that the particle size of the SARS-CoV-2 virus that leads to COVID-19 is around 0.1 microns. This is much smaller than what may be picked up by these air filters. As this chart shows, the virus lives in the invisible region, while others like dust, cat dander and human hair are visible to the human eye.

Sizes of various items shown in Microns. Invisible items in black area on chart, including the SARS-CoV-2 Virus.

Luckily, the SARS-CoV-2 virus doesn’t travel through the air own its own. It rides on respiratory droplets and droplet nuclei (dried respiratory droplets) that are predominately 1 micron in size and larger. These filters have various efficiencies at capturing the viruses that are in the 1-to-3-micron range according to ASHRAE.

The SARS-CoV-2 virus riding a respiratory droplet in the 1 to 3 micron range

ASHRAE

As the chart shows, ASHRAE recommends using a minimum of a MERV 13 filter, which is at least 85% efficient at capturing particles in the 1 to 3-micron size range. A MERV 14 filter is at least 90% efficient at capturing those same particles. High-efficiency particulate air (HEPA) filters are even more efficient at filtering human-generated infectious aerosols.

MERV Rating and Air Filter Efficiency for Particle sizes 1 to 3 microns in size

By definition, a HEPA air filter must be at least 99.97% efficient at capturing particles 0.3 micron in size. This 0.3-micron particle approximates the most penetrating particle size (MPPS) through the filter. HEPA filters are even more efficient at capturing particles larger AND smaller than the MPPS. Thus, HEPA air filters are more than 99.97% efficient at capturing airborne viral particles associated with SARS-CoV-2 which leads to COVID-19.

Checkout these HEPA Filters for your Home or Office

HEPA filters can capture and trap microorganisms, including viruses and bacteria, helping to reduce the risk of respiratory infections. So, if possible, use the highest MERV rated air filter with your system, or get a portable HEPA air filter for your room or office. HEPA filters are the most efficient at capturing small microorganisms like the SARS-CoV-2 virus.

Where are HEPA Filters used?

HEPA air filters are used in residential, commercial, and industrial facilities. In homes there are portable types that can be moved from room to room, and others that can be installed in a central air conditioning system serving the whole house.

HEPA air filters are also used along with ULPA filters in cleanrooms, labs, and other spaces requiring a very clean environment.

Asthma and Allergy Management

For individuals with asthma, HEPA filters help reduce asthma triggers like airborne irritants and respiratory allergens. According to the Asthma and Allergy Foundation of America (AAFA), nearly 26 million people have asthma in the United States. There are 4.8 million children under the age of 18, and nearly 21 million adults suffering from asthma. On average, 10 people in the unites States die every day from asthma. A total of 3,517 deaths in 2021.

According to the AAFA over 100 million people each year in the United States experience various types of allergies. Allergies are the sixth leading cause of chronic illness in the U.S. HEPA filters are highly effective at removing allergens such as pollen, dust mites, and pet dander, providing relief to allergy sufferers.

Editorial Process:

Some of the links in this article may be affiliate links, which can provide compensation to the MEPAcademy at no cost to you if you decide to purchase. Our reviews and articles are made by an industry professional experienced in the engineering and construction of commercial buildings.

Air Filters vs COVID-19

HVAC Equipment Cost Database

MEP Academy Instructor

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May 10, 2021

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Are you paying too much for your HVAC equipment? How do you know if the quote you received for your equipment is a fair price? Do you have a method of comparing what you have paid for various HVAC equipment with what is being quoted currently?

Keeping track of the cost of HVAC Equipment allows you to quickly provide budgets and check the cost of equipment before you purchase. This database allows you to easily keep track of the most common HVAC equipment.

HVAC Equipment Cost Database

Using an HVAC Equipment cost database will save you a lot of money by avoiding the costly mistake of paying too much for equipment.

Air Conditioners price per ton and price per square feet historical equipment pricing database — Air Conditioners in Historical Pricing HVAC Equipment Database

Get your copy here. HVAC Equipment Cos t Database

The HVAC Equipment Cost database keeps track of all your equipment quotes or purchases for easy reference and parametric checks, such as cost per ton ($/Ton), cost per CFM ($/CFM)

HVAC Piping Unit Pricing

MEP Academy Instructor

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August 31, 2020

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For an HVAC Piping Estimators the need for quick budgets for the installation of piping is best handled with a spreadsheet of different material types and sizes. Having an estimating software program can make this process a lot easier, as the material pricing is always up to date and can be entered into the spreadsheet quickly. You can get a copy of this spreadsheet to help you price piping fast and efficiently.

HVAC PIPING UNIT PRICING

Often the requirements of the RFP or bidding instructions will call for the price per foot to install piping beyond that which is required by the contract drawings. Such pricing maybe used for change-orders. Having these numbers available and updated often also gives you a quick reference for budgeting projects. It’s good to know when doing job site comparisons of different piping options or during discussions with engineering, what the cost is for the various piping sizes and types of materials.

COST PER FOOT

The cost per foot for the installation of piping needs to include fittings and hangers prorated into the value. It’s best to look at a standard length of pipe and then figure that you will have a Tee and 90 degree elbow in that length.

So for example, using twenty feet of copper water pipe with a Tee and 90 degree elbow plus the hangers to build a unit price would represent a field condition of a fitting every ten feet.

For higher density projects like Hospitals you could put more fittings in your unit pricing. Total those cost up and then divide by 20 to derive at a cost per foot for that particular size and material type.

20 feet of pipe + 2 Fittings + 3 Hangers / 20 = Cost per Foot

If the piping is insulated, you can also put the values in for insulation.

The Estimating Wizard provides two spreadsheets for tracking unit pricing, one for HVAC Piping and the other for Plumbing piping. Get a copy and start tracking your cost per foot, or be prepared to give a quick budget based on your knowledge from your spreadsheet of unit prices. Watch the video below to see how quick and easy it is to track the cost per foot for various sizes and material types.

MEP Academy HVAC Piping Unit Pricing Spreadsheet

The MEP Academy provides a spreadsheet that makes calculating unit pricing simple. The spreadsheet is available by following this link, HVAC Piping Unit Pricing Spreadsheet

HVAC Piping Unit Pricing Calculator Example

In the screenshot above there is a place for you to build your hanger requirements (#1), and a place to put your tax rate and hourly labor rate (#2).

For each size of pipe and material type you would insert the unit cost for Material (#3) and Labor (#4).

Under item (#5) you would build your typical run of pipe and enter the quantity of fittings you might expect for the type of building and system. You would add whatever you think will be required for every so many feet of pipe. In the example above we are showing that for every 20 feet of pipe you will have 1 Elbow and 1 Reducing Tee.

Under item (#6) you would add the cost per lineal foot for insulation if required. You could also look at insulation as a separate value and leave the pipe bare.

Line item (#7) is where you indicate the hanger spacing, and for each hanger you defined under item (#1) you will get the quantity as defined by the linear feet in item (#5) divided by your hanger spacing, which will affect your cost.

Line item (#8) is the calculated cost per linear foot of piping for that size and material type of pipe.

Summary Sheet

After you have all your unit pricing information inputted into the spreadsheet, all you have to do to get a budget for installing piping is to enter the quantity of piping (#9) for each size and material type (#10). The system will automatically calculate the cost (#11) to install that run of piping based on your unit pricing data. The total cost will be shown at the top of the spreadsheet (#12).

Piping Unit Pricing Calculator Summary Page

You can get your copy here. HVAC Piping Unit Pricing Spreadsheet

AC Condensate Drain Sizing and Layout

MEP Academy Instructor

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August 17, 2020

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The proper sizing and layout of condensate drain lines is important for the protection of property and for the proper functioning of the air conditioning equipment.

If you prefer to watch our YouTube version of this presentation, scroll to the bottom.

Condensate Drain Pipe Sizing

The size required for the condensate pipe is dictated by the local code. Enclosed you will find the requirements for many local codes, but be sure to check your code for your local requirements. If the outlet size of the equipment’s condensate drain is larger than what’s shown in this chart then your required to use the larger outlet size.

Slope to be at least 1/8” per foot or 1 percent, that is for every 12” horizontally there must be at least an 1/8” drop vertically.

Condensate drain piping to slope a minimum of 1/8" per every 12" horizontal — Condensate drain piping to slope a minimum of 1/8″ per every 12″ horizontal

Attics or Furred Spaces

If the Air Conditioner is suspended above an inaccessible ceiling, such as a gypsum board ceiling or attic space then you will need to provide a means for protecting the building elements from the overflow of the primary drain and for indicating that there is a leak.

Also, drain pans that are poorly drained can cause water to stay in the pan risking the possibility of algae and bacteria growth. Below are some possible solutions, but as always check your local code for the approved method.

Option 1 – Secondary drain pan with drain piping. This would hang below the Air Conditioning unit in case the A/C units primary pan overflowed. Also, there is a requirement to provide secondary drain piping to a point of termination that would provide notification to the occupants that there is a leak, such as terminating above a window or doorway.

Option 1 - Secondary drain pan with piping terminating in observable location — Option 1 – Secondary drain pan with piping terminating in observable location

Option 2 – An additional drain pipe connection that sits above the primary drain connection and whereby the secondary drain piping terminates in a location to alert the occupants of the clogged primary drain.

Option 2 - Secondary drain piping connection to primary drain pan — Option 2 – Secondary drain piping connection to primary drain pan

Option 3 – Leak detection device that automatically shuts down the Air Conditioner if the primary drain becomes clogged.

Option 3 - Primary drain with leak detection device — Option 3 – Primary drain with leak detection device

Option 4 – Secondary drain pan with leak detection, located beneath the coil that shuts down the unit upon a leak.

Option 4 - Secondary drain pan with leak detection — Option 4 – Secondary drain pan with leak detection

The additional drain pan or drain pan connection shall be provided with a drain pipe that will determinate in an observable area, such as in front a window or above a doorway, and be of a size not less than 3/4”. Secondary drain pan shall not be less than 1-1/2” in height and extend 3” wider on each side of the coil or AC unit.

Secondary drain piping terminating above window. Pipe doesn't have to be visible as shown. — Secondary drain piping terminating above window. Pipe doesn’t have to be visible as shown.

Drain Termination

Where can and can’t you terminate the air conditioners condensate drain piping? There are several options where you can terminate the condensate drain line;

Indirect Drain
Condensate Pump to Indirect Drain
Drywell
Leach pits
Landscaped areas that are properly designed to handle the volume of condensate
To Properly designed stormwater treatment systems.

Indirect Drain

Lavatory tailpiece in the same tenant space as the air conditioner
Laundry standpipe
Janitors Sink
Inlet of Bathtub Overflow – Must be accessible
Collect and send to cooling tower (See description below)

Cooling Coil condensate to sink tailpiece.

The connection to a plumbing fixtures tailpiece has to be made within the same tenant space as the air conditioner cooling coil that is generating the condensate.

Drywell

A drywell can be used for the termination of your air conditioners condensate drain. Check your local code for the specifics, but generally it includes some or all of the following depending on whether it’s for residential or a commercial project:

A minimum size hole, such as 2 foot by 2 foot by 3 feet deep, or a round hole such as 12” diameter by 3 feet deep.
A minimum of 6” of soil or concrete shall provide cover above the rocks
Some form of barrier between the soil and the top of the drywell where the rock begins, such as building paper or plastic
Drywell to be filled with gravel or crushed rock, often with a stated minimum size rock such as 1 inch diameter
The termination of the condensate drain pipe shall connect indirectly to the drywell drain pipe.
The drywell drain pipe to be a minimum of 1-1/2” PVC or other approved material.
Drywell to be at least three feet away from the building structure or any footings.

Drywall for Air Conditioner Cooling Coil Condensate

There are various methods of providing drywells depending on the local code. There are prefabricated drywells that can be used and ones that are made by using a large diameter piece of PVC pipe or similar material.

Some codes will require you to collect the condensate from cooling coil drain pans and return it to the cooling tower if the equipment is served by a cooling tower and the total combined capacity of the HVAC cooling coils exceeds a certain amount like 65,000 btu/hr.

This is a water conservation measure, and there are some exceptions to this requirement, such as if the total capacity of the AC Equipment cooling coils are less than 10% of the total capacity of the cooling tower, or if the location of those AC Cooling coils are in a remote location, far from the tower.

Some locations where you can’t terminate condensate;

Public ways
Sidewalks
Driveways
Alleys

No termination of condensate on public area ways

Excluded from Code Requirements

Excluded from these codes are non-condensing type of equipment like radiant cooling panels that are designed to prevent condensate from occurring by keeping the temperature of the chilled water above the dew point temperature/vapor pressure of the surrounding air. These are system designed to operate in sensible cooling only modes.

Piping Material

The material types that can be used for condensate drain piping varies by jurisdiction but the most commonly cited materials are:

Copper
PVC – DWV
CPVC
ABS – DWV
Polyethylene
Galvanized steel
Cast iron.

Also the use of short radius 90-degree elbows are often prohibited. You can normally use standard fittings until you reach a certain size at which point you might be required to use drainage pattern fittings (DWV)

Traps

Traps are to be installed as required per the manufactures recommendation. No traps are required on the secondary drain pan, this is to allow immediate notification that the primary drain has failed.

Cleanouts

Cleanouts are required in case of plugged drain pipes. Provide as required to prevent the need to cut drain pipes for unplugging. Some of the following maybe used for cleanouts if approved by your local code authority;

Plugged tees
Union connections
Short clamped hoses at the unit (see image above)

When you have more than one air conditioning unit condensate tied to a main condensate pipe, then every change of direction shall have some method of cleanout. Check your local code as this maybe a requirement for even a single air conditioners condensate piping.

Condensate Pumps

Condensate pumps can be used to elevate the condensate vertically to a point where it will then discharge into a code approved gravity sloping condensate drain line. The condensate pump should be interlocked with the Air Conditioning Unit to prevent its operations if the condensate pump is inoperable.

Checkout these Condensate Pumps

Please remember that code requirements are always changing, so check for the most current code in your area at the time of design and installation. Or ask an inspector for the current installation practice.

Refrigerant Line Sets

Video of this Article

MEP Academy Estimating Spreadsheet

MEP Academy Instructor

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July 14, 2020

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Having an MEP Academy Estimating Spreadsheet that automates portions of your estimates, will save you valuable time that could be used to make more sales. All aspects of the cost of furnishing and installing an HVAC and/or a Plumbing system is contained in one spreadsheet made specifically for the MEP industry. For plumbing only see below.

For a Plumbing only Spreadsheet, use this Commercial & Residential Version. Plumbing Only. For a simple Residential HVAC & Plumbing Spreadsheet. Residential version.

Dashboard

The Main Dashboard provides you with all the information you need to make a quick decision on whether to make further adjustments, or if one of the metrics looks out of place based on historical data. The Dashboard gives you a quick overview of all that is going on within the Estimating Spreadsheet.

Estimating Dashboard within the MEP Academy Estimating Spreadsheet

Your MEP Academy Estimating Spreadsheet needs to be able to handle rental equipment, general conditions, subcontractors, piping and plumbing takeoffs, sheet metal, labor rate tables with crew mix capabilities, , and a bid summary. Each sheet in the estimating spreadsheet automatically calculates the values you enter, showing you a new total bid amount.

Will cover portions of the MEP Academy Estimating Spreadsheet starting at the back of the Excel spreadsheet and working our way toward the front summary page last.

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Labor Rate & Crew Mix Table

Choose your crew mix based on the level of experience and the different pay scales based on each project. Pick any combination and quantity of tradesman based on the requirements of the project.

Labor Rates and Crew Size within the MEP Academy Estimating Spreadsheet

There is a separate crew labor rate for HVAC Piping Shop & Field, Sheet Metal Shop & Field, and Plumbing.

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HVAC & Plumbing Equipment

Enter the project equipment price and labor to rig the HVAC and Plumbing equipment into place. Compare supplier pricing easily side by side. The MEP Academy Estimating Spreadsheet automatically selects the lowest bidder but lets you override that decision.

HVAC Equipment page within the Estimating Spreadsheet

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General Conditions

Do you need a jobsite trailer or onsite management? Enter the quantity and level of the staff required to run the project, whether one person or dozens. Set the quantity and duration of each general condition, along with the rate. General Conditions is broken down into three sections as follows: #1 – Management, #2 – Construction Office (Non-Reoccurring Expenses), and #3 – Construction Office (Reoccurring Expenses).

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HVAC & Plumbing Subcontractors

HVAC & Plumbing contractors often subcontract out for Air & Water Balance, Sheet Metal & Piping Insulation, Water Treatment, Building Automation, Excavation and other specialty trades that they don’t self-perform. This spreadsheet was made especially for the HVAC & Plumbing contractor and their most often used subcontractors.

Subcontractors – Rentals – GC’s – Engineering Pages

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Plumbing Fixtures

For those contractors that do plumbing the following Plumbing Fixture sheet will give you a place to record your vendors quotes and the labor it takes to install each type of fixture. What is also revealed is the overall cost per fixture.

Plumbing Fixtures page within the Estimating Spreadsheet

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MEP Specialty Sheets

Each trade has a specialty sheet for those items that aren’t considered equipment or a fixture, but for which there is a cost impact. The MEP Academy Estimating Spreadsheet includes Sheet Metal, HVAC Piping & Plumbing Specialty sheets.

HVAC and Plumbing Specialty Pages within the Estimating Spreadsheet

Specialty Sheet In Estimating Spreadsheet — Specialty Sheets in Estimate Spreadsheet

Material & Labor Summary Sheets

You will find a Sheet Metal, HVAC Piping & Plumbing material & labor summary sheets where all of the other specialty sheets are summarized for your review and last minute edits. Each sheet will be divided between field & shop fabrication work. The first section covers the field installation items.

Sheet Metal Material and Labor Summary – Estimating Spreadsheet

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Field Summary Section

This is where you will put your material takeoff information for the following:

Rectangular & Round Ductwork
HVAC Piping
Plumbing Piping

This is also where the other sheets that you filled out will be summarized, such as the following;

HVAC & Plumbing Specialties
HVAC & Plumbing Equipment Labor
Plumbing Fixtures

Material & Labor Summary Sheet in Estimating Spreadsheet — Material and Labor Summaries

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Each of the field labor summary sheets contain a row to add for the following

Material Handling
Consumables
Punch List
Cleanup
Detailing
Supervision

Shop Fabrication Summary Section

For those of you that have a fabrication shop, there is a section to add material and labor.

Rentals

For those HVAC air conditioning and Plumbing projects that require a crane, fork lift, scissor lift or any other equipment that you don’t own but will be required on the project. Having a spreadsheet that maintains a list of the most common equipment you normally rent along with their rental rate will save you time and money while avoiding having to call for pricing on every job.

Engineering

If you do your own design then you should have a sheet of each of the personnel responsible for spending time on the engineering task. If you’re doing design/build work, but don’t do the engineering yourself, but hire a third party, then you should add some engineering review time. It’s your responsibility to manage your third-party engineer to make sure they design within your cost parameters.

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Estimate Summary

All of your estimates are summarized on the last tab of the MEP Academy Estimating Spreadsheet for easy review. You can quickly scan each of the categories to see where all the project cost has shown up. There is the labor and material summary for HVAC Sheet Metal, HVAC Piping, and Plumbing and another section for Subcontractors, General Conditions, Rentals, etc.

Estimating Spreadsheet Summary Page

Estimating Summary — MEP Academy Estimating Spreadsheet Summary

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Bid Risk Assessment Form

The MEP Academy Estimating Spreadsheet contains a bid risk assessment form that rates the success of winning any particular project that you are contemplating pursuing. The risk assessment form will help you determine if the project is worth bidding based on a set of questions that rate your answers.

The answers to these questions will give you a score from which you can use to see how the project rates on a scale of risk and reward. The total risk assessment score will also inform you which level of approval is required within your company depending on how you rate your risk values as the example shown below. The total score is 25, which according to this contractor would require the Vice President to sign-off on the project or approve the decision to pursue bidding on the project.

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MEP Academy Estimating Spreadsheet Summary

The MEP Academy Estimating Spreadsheet is used to gather all the information for estimating a project, putting it into a format where you can make quick adjustments and decisions while the spreadsheet gives you an immediate update on the price.

Purchase this spreadsheet at its currently reduced price of ONLY $245.00, which usually sells for ~~$599.00~~

Watch the YouTube video below to see the MEP Academy Estimating Spreadsheet in action.

Automatic Transfer Switch

Electrical

MEP Academy Instructor

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November 22, 2023

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Maintaining uninterrupted electrical power is very important for some facilities and processes. Think of a hospital. What would happen if the power went out during a surgery? What would happen to a patient connected to oxygen or life support machine dependent on electricity?

If you prefer to watch the video of this presentation, the scroll to the bottom.

Whether it’s a hospital, a laboratory, a manufacturing facility, or any other critical infrastructure, a sudden utility power outage can have severe consequences. This is where Automatic Transfer Switches (ATS) can ensure the seamless transition to backup power sources. In this article, we’ll explore how ATS is employed to maintain power during utility outages and why they are a fundamental part of various construction projects.

How Automatic Transfer Switches Work

Automatic Transfer Switches are devices that monitor the quality of the primary power source, which is typically the utility grid, and automatically switch to an alternative power source when an outage is detected. Here’s how they work:

Automatic Transfer Switch (ATS) Wiring Diagram

An ATS system is designed to connect to two power sources: the primary utility power and a secondary backup power source, often a generator.

During normal operation, the ATS connects the load to the primary power source. The controller keeps a close eye on the quality of this power source.

ATS systems are equipped with sensing devices that continuously monitor the voltage and frequency of the primary power source. When the controller detects an interruption in the primary power supply, it automatically initiates a transfer to the secondary source, typically a generator. This swift response is critical for critical applications such as hospitals and data centers. This transfer occurs in less than 1 second.

Switch Mechanism

The heart of the ATS is its switch mechanism, which is responsible for making and breaking electrical connections. It ensures that only one power source can be connected at a time, preventing any back feeding of power.

Automatic Transfer Switch Sequence of Operation

Before making the transfer to the secondary source, the ATS ensures that the generator’s output matches the utility power in terms of voltage, frequency, and phase. This synchronization is vital to protect sensitive equipment from damage.

Once the utility power is restored and stable, the ATS automatically switches the load back to the primary source, ensuring that the backup source is used only when necessary.

The Role of ATS in Commercial Construction

1. Hospitals: In hospitals, where uninterrupted power is critical for life-saving equipment, ATS systems ensure that surgeries, intensive care units, and other essential functions continue without interruption during power outages.

2. Laboratories: Research facilities and laboratories rely on precise and stable power for experiments and sensitive equipment. ATS systems guarantee that experiments aren’t compromised due to power disruptions.

3. Manufacturing Facilities: Manufacturers can’t afford production downtime due to power outages. ATS keeps assembly lines running smoothly and avoids costly interruptions.

4. Data Centers: Data centers house mission-critical data, and even a brief power interruption can lead to data loss. ATS is essential in these facilities to maintain uninterrupted operation.

5. Hotels: In the hospitality industry, guest comfort and safety are top priorities. ATS systems ensure that guests aren’t inconvenienced by power disruptions.

Critical Power Backup options using an ATS

Conclusion

Automatic Transfer Switches are unsung heroes in the world of commercial construction. They play a vital role in ensuring uninterrupted power in critical applications, from hospitals to laboratories, manufacturing facilities, data centers, and beyond. For those in the construction industry, understanding the importance of ATS systems is key to delivering projects that meet the highest standards of reliability and safety. These unassuming devices are the backbone of power continuity in our modern world, making sure that when the lights go out, the show goes on.

How an ATS Switch Works

Chilled Water Pumping Options

MEP Academy Instructor

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November 16, 2023

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In this article we’ll discuss the three different pumping methods used in a central plant for the distribution of chilled water. This includes primary variable flow, primary/secondary with distributed pumping, and primary/secondary variable flow with tertiary pumping. There are many other pumping configurations, but in this article we’ll cover the first three.

If you prefer to watch the video of this presentation, than scroll to the bottom.

Primary Variable Flow Chilled Water Pumping

In a primary-only variable flow chilled water system, the operation is centered around using only primary pumps to circulate chilled water through the entire system. The key feature of this system is the variation of flow rates in response to the cooling load. This provides a more energy-efficient operation. Here’s an overview of how the primary-only variable flow chilled water system pumping arrangement typically works:

Primary only variable chilled water pumping

Chillers

Chilled water is generated by one or more chillers in the system. There is a chilled water temperature sensor in the chilled water supply pipe leaving the chiller. The chiller cools the water to the desired chilled water supply temperature before it is sent to the cooling coils.

The 3-way valve ensures that the chiller receives the minimum flow required by the chiller manufacturer. The 3-way valve bypasses the coil when the demand for cooling is reduced at this coil. This provides the chiller with a minimum amount of flow. There are better ways to do this that we’ll cover in another video.

The chilled water is then distributed to the various cooling loads, such as air handling units (AHUs), fan coil units (FCUs), or other cooling devices in the building. The chilled water is distributed using variable speed pumps.

Primary Chilled Water Pumps

The system relies on one or more primary chilled water pumps to circulate water through the chillers and the entire distribution system. These pumps are typically equipped with variable frequency drives (VFDs). The VFD’s adjust the pump speed and flow rates based on the demand. VFDs on the primary pumps allow for the adjustment of the pump speed to match the varying cooling load. Lower pump speeds during periods of lower demand contribute to energy savings. The demand is determined by a differential pressure sensor installed at a remote location.

Differential Pressure Sensor

The cooling coils have supply air temperature sensors that control the amount of chilled water flowing through the control valves. As demand in the space reduces, the 2-way valves modulate toward the closed position. This causes an increase in pressure within the chilled water system. This increase in pressure is sensed by the differential pressure sensor and is communicated to the VFD. The VFD then slows down the speed of the pump, which reduces the amount of chilled water circulated throughout the system.

Energy Efficiency

The system’s energy efficiency is enhanced by avoiding the need for secondary pumps and the associated energy consumption in a primary-secondary system. The variable flow nature ensures that the system operates at optimal conditions, minimizing energy wastage.

Dynamic Control in Central Plant

The system continuously adapts to changes in the cooling load. This provides dynamic control and improved efficiency over traditional constant flow systems.

This primary-only variable flow chilled water system offers a flexible and energy-efficient solution by adjusting the flow rates in the primary loop based on real-time cooling demand. It’s particularly suitable for applications where load variability is a significant factor.

Primary/Secondary with distributed Pumping

In a primary/secondary variable flow chilled water system with a distributed pumping arrangement, the operation involves two separate loops. There is a primary loop and a secondary loop. This design is often employed in larger and more complex chilled water systems, including more than one building. Here’s an overview of how the system typically operates:

Primary Chilled Water Pumps in Central Plant

One or more primary pumps circulate chilled water through the chillers and the primary loop. In this design there is a pump dedicated for each chiller. A common leg connects the primary and secondary loops.

Secondary Chilled Water Pumps

The secondary pumps are outside the central plant and into the buildings, bringing them closer to the cooling coils. The pumps provide the pressure required to bring the water from the common leg through their most remote coil and back to the common leg. These pumps will also operate using VFD’s to match the load of the coils they serve.

Energy Efficiency in Chilled Water Central Plant

The primary/secondary design allows for more precise control over the distribution of chilled water to the loads. This avoids over pressurizing the secondary loop which can occur when the secondary pumps are located within the central plant.

By separating the loops, the system can adapt to changes in the secondary loop without affecting the primary loop. Thereby contributing to overall energy efficiency.

Distributed pumping offers redundancy and flexibility, allowing for continued operation even if one secondary pump is offline for maintenance or repair.

This primary/secondary variable flow chilled water system with a distributed pumping arrangement is a robust solution for larger commercial buildings. This allows for precise control, energy efficiency, and redundancy are critical considerations.

Primary/Secondary Variable Flow with Tertiary Pumping

In a primary/secondary variable flow chilled water system with tertiary pumping, the operation involves three separate loops. There is a primary loop, a secondary loop, and a tertiary loop. This design is employed in large and complex chilled water systems to optimize control and enhance energy efficiency. The primary and secondary pumps can be located in the central plant, thereby allowing the tertiary pumps to be located in the individual buildings where the cooling coils are located. Here’s an overview of how the system typically chilled water pumping operates in this system:

Primary secondary with tertiary pumping. Central Plant

Chilled Water Pumping

Primary chilled water pumps circulate chilled water through the chillers and the primary loop within the central plant.

Secondary chilled water pumps in the central plant circulate chilled water through the secondary loop. The secondary pumps respond to fluctuations in the cooling load requirements within the system using VFD’s.

Tertiary pumps circulate chilled water through the tertiary loop within each building. Tertiary pumping loops are dedicated to specific loads or areas that have unique cooling requirements. You might find this system on the campus of your local University which has a central plant and buildings distributed throughout the campus.

These pumps are provided with VFD’s to regulate the flow based on the specific needs of the tertiary loads within the building.

Variable Frequency Drives (VFDs):

Primary, secondary, and tertiary pumps are typically equipped with variable frequency drives (VFDs) to adjust pump speed and flow rates based on real-time demand. This flexibility ensures that the system operates efficiently under varying conditions.

Energy Efficiency in Central Plant

The primary/secondary/tertiary design allows for precise control over the distribution of chilled water to different types of loads with varying cooling requirements. By separating the loops, the system can adapt to changes in each loop without affecting the others, as a result it contributes to overall energy efficiency.

Dynamic Control and Redundancy

The system provides dynamic control, adapting to changes in the cooling load in real time for each loop. The inclusion of a tertiary loop offers additional redundancy and flexibility for meeting specific cooling needs.

This configuration provides a high level of control and efficiency, making it suitable for large and diverse commercial buildings with complex cooling demands.

Central Plant Chilled Water Pumping Options

Chilled Water Central Plant

MEP Academy Instructor

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November 10, 2023

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In this article we’ll discuss the basics of a chilled water central plant. The main pieces of equipment include a water-cooled chiller, cooling tower, air handler, controls, and the chilled-water and condenser water pumps.

If you prefer to watch the Video of this presentation than scroll to the bottom or click on the following link. Chilled Water Central Plant Basics.

We covered chillers in another video, but we’ll go over the basics here. The chiller contains a refrigeration circuit with the typical components found in a standard air conditioner. There is a compressor that circulates the refrigerant, a condenser, and the evaporator.

There are two main loops of water fed from the chiller, one comes from the evaporator and the other from the condenser. The chilled water pumps circulate water from the chiller’s evaporator to the air handler through piping, this comprises the chilled water loop. Then there is the condenser water pump that circulates water from the chiller’s condenser to the cooling tower, this comprises the condenser water loop.

These makeup the two main water loops found in a water-cooled chiller plant. The chilled water loops purpose is to absorb the heat from the building. The condenser water loops purpose is to reject that heat to the atmosphere.

Chilled Water Loop

The chillers evaporator in the central plant produces chilled water. This CHW which is sent to the air handlers cooling coil and fan coils that serve the building occupants.

The air handlers and fan coils circulate warm air over their chilled water coils. The coils cools the air sent back to the occupied spaces. The heat from the spaces is sent back to the chillers evaporator in the chilled water return piping. That heat is absorbed into the chillers refrigerant circuit of the evaporator. The compressor then increases its pressure and temperature before sending to the condenser.

Condenser Water Loop

The cooling tower is responsible for rejecting the heat captured from the spaces. The warm refrigerant in the condenser passes the heat onto the condenser water. The warm water leaving the chillers condenser enters the cooling tower.

The warm water trickles down over the cooling tower fill. The warm water gives up its heat through evaporation to the air be drawn in by the cooling tower fans. The condenser water pump circulates this cooler water from the bottom basin of the cooling tower back to the chillers condenser to repeat the cycle.

This is the basic operation of a chilled water central plant. It includes the production of chilled water used to cool the air that serves the occupants of the building. The pumps circulate that water between the chiller and the other components. The air handlers’ job is to pick up the heat from the space by passing the warm air over the cold chilled water coil.

This is the first in our series on Central Plants and their operation. See our other videos on How Air-Cooled and Water-Cooled Chillers work”, and on “How Cooling Towers Work”.

Chilled Water Central Plant

Dual Duct System

HVAC Systems

MEP Academy Instructor

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November 4, 2023

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In this article we’ll discuss the dual duct system and mixing boxes. Dual duct mixing boxes help regulate the temperature and airflow in buildings by mixing hot and cold air to achieve the desired conditions.

If you prefer to watch the video of this presentation, than scroll to the bottom.

Here’s how a dual-duct system works.

Depending on the configuration, an air handler can be provided with one or more fans. Next, there will be a heating coil and boiler to provide heat, while a chilled water coil and chiller will provide cooling. There are also other sources available for heating or cooling.

There will be two main ducts leaving the air handler. One for heating, and the other for cooling, which makes this a dual-duct system.

Dual-Duct Mixing Box

Each zone will have its own dual-duct Mixing Box, that can be either constant or variable volume. This allows one zone to be in cooling, while another zone can be in heating. Dual duct boxes are made of galvanized steel and contain two dampers. Each damper has a controller located on the outside of the box. A flow sensor is in the hot and cold inlets of the box allowing for accurate measurement of the air flow.

Dual Duct System with Hot and Cold Decks

A room-based temperature sensor or thermostat will continuously monitor the indoor temperature. These sensors provide feedback to the HVAC control system. The control system analyzes the temperature data and determines the required airflow and temperature to maintain the desired conditions.

The dual duct mixing box operates by adjusting dampers within the box. These dampers control the amount of cold and hot air that is mixed before being distributed to different zones within the building.

Mixing Box Operation

There are various control strategies for dual-duct boxes. One strategy is for there to be no blending of the hot or cold air, which looks like this.

When the thermostat calls for cooling, the damper on the hot air duct closes, and the cold air damper modulates from zero to maximum. This allows cold air to enter the mixing box.

Dual Duct Mixing Box Chart - No Blending of hot and cold duct air — Dual Duct Mixing Box Chart – No Blending of Hot or cold duct air

Conversely, when heating is needed, the damper on the cold air duct closes, and the damper on the hot air duct opens.

Then there are various blending strategies where a mixture of cold and warm air will mix during certain conditions.

Dual-duct mixing terminal chart - Mixing of hot and cold air streams — Dual-duct mixing terminal chart – Mixing of hot and cold air streams

As the temperature sensor approaches the setpoint in cooling mode, the cold air damper will modulate from maximum to a minimum setpoint. When the temperature continues to drop the hot air damper begins to open creating a mixed air flow. While the temperature continues dropping, the cold air damper completely closes, and the hot air damper modulates to maximum open position.

There are two separate ducts for supplying air. One duct carries cold air, while the other carries hot air. After mixing, the conditioned air is distributed to various areas of the building through separate ductwork.

Each zone may have its own mixing box, allowing precise control over the temperature and airflow in different parts of the building. Again, this allows any zone to be in either heating or cooling mode.

Dual Duct Air Handler and Dual Duct Mixing Boxes

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Primary Variable Flow Chilled Water Pumping

Chillers

Primary Chilled Water Pumps

Differential Pressure Sensor

Energy Efficiency

Dynamic Control in Central Plant

Primary/Secondary with distributed Pumping

Primary Chilled Water Pumps in Central Plant

Secondary Chilled Water Pumps

Energy Efficiency in Chilled Water Central Plant

Primary/Secondary Variable Flow with Tertiary Pumping

Chilled Water Pumping

Variable Frequency Drives (VFDs):

Energy Efficiency in Central Plant

Dynamic Control and Redundancy

Chilled Water Loop

Condenser Water Loop

Here’s how a dual-duct system works.

Dual-Duct Mixing Box

Mixing Box Operation

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