Construction Safety for contractor success. This is the fifth article in our series on what it takes to create and sustain a successful construction contracting company. See why Construction Safety is one of the key factors for creating a successful construction company.
Construction sites are inherently hazardous, with workers exposed to a wide range of risks and dangers. Construction sites are characterized by heavy machinery, high elevations, and exposure to hazardous materials, all of which can result in accidents, injuries, and fatalities. Ensuring construction safety is important for several reasons:
Here are 6 reasons why construction safety leads to contractor success:
Protecting Workers: Construction sites are inherently dangerous places, with many hazards present, such as falls from heights, electrocutions, and being struck by heavy machinery or equipment. Ensuring safety in construction helps to prevent accidents that can result in injury or death of workers, which is the most important reason for prioritizing construction safety. Workers in the construction industry have a right to work in a safe and secure environment, and employers have a duty to provide a safe workplace.
Legal Compliance: Governments around the world have implemented strict regulations to ensure the safety of workers in the construction industry. Companies must comply with these regulations to avoid legal action and fines, and to maintain a good reputation.
Financial Impacts: Accidents on construction sites can result in significant financial losses for companies. In addition to legal penalties and fines, accidents can lead to delays in construction, increased insurance premiums, and decreased productivity. By ensuring construction safety, employers can reduce costs associated with accidents and injuries.
Productivity: A safe working environment can increase productivity. When workers feel safe, they can focus on their work more effectively and avoid costly distractions. A safe work environment helps to enhance productivity by reducing the likelihood of accidents and injuries that can result in lost time, delays, and increased costs.
Reputation: A company with a good safety record is more likely to attract and retain workers and clients. This can help to build a positive reputation in the industry and promote continued growth and success.
Workers Compensation: Accidents increase the cost of doing business and raise insurance premiums. A workers compensation rate below 1.0 indicates that the employer’s claims experience is better than average, resulting in a credit or discount on their workers’ compensation premiums. Conversely, a rate above 1.0 indicates that the employer’s claims experience is worse than average, resulting in a surcharge or increase in premiums. Some projects require a history of safe construction practices with a low rate of accidents to qualify to participate in bidding.
Overall, construction safety is essential for protecting workers, reducing costs, enhancing productivity, building trust in the construction industry, and for the success of a construction company.
Refrigerant recovery is the process of removing refrigerant from a refrigeration or air conditioning system for recycling, reclamation, or disposal. It is an essential step in the maintenance and repair of refrigeration and air conditioning systems. Proper refrigerant recovery is important to protect the environment and comply with regulations.
Refrigerant Recovery Process using the VEVOR RR500 Recovery Machine and 30 Lb Tank
Here are some key steps involved in refrigerant recovery:
Prepare the equipment: The recovery equipment should be properly maintained and calibrated before starting the recovery process to make sure everything is operating properly. The hoses and fittings should also be checked for leaks.
Refrigerant Recovery: The refrigerant is removed from the system using a recovery machine like the Vevor RR500 shown here which uses 110-120v 60 Hz power with a powerful 3/4 Hp dual-cylinder oil less compressor. The refrigerant is typically pumped into a recovery cylinder for storage and transportation, like the Vevor 30 Lb. tank shown here which comes prefilled with a trace amount of nitrogen to guard against corrosion and has a working pressure of 400 psi. The recovery equipment should be connected to the system using the appropriate hoses and fittings. The hoses should be purged of air before connecting to the system.
Recover the refrigerant: The refrigerant should be recovered from the system using the Vevor recovery equipment. The amount and type of refrigerant recovered should be documented for compliance with regulations including the EPA’s mandatory section 608. Section 608 states that the Technicians disposing of appliances containing between 5 and 50 pounds of refrigerant must keep records of the disposal.
Refrigerant Storage: The recovered refrigerant should be stored in a properly labeled container and transported to a recycling facility for reuse or disposal. The recovered refrigerant is stored in a DOT-approved cylinder that is designed for refrigerant storage. The cylinder must be properly labeled with the type of refrigerant, the amount of refrigerant, and the date of recovery.
Refrigerant Disposal or Recycling: The recovered refrigerant can either be properly disposed of or recycled for reuse. Disposal methods can vary depending on local regulations, but typically involve sending the refrigerant to a licensed facility for destruction. Recycling involves filtering and cleaning the refrigerant to remove impurities before it can be used again.
Clean up: Any residual refrigerant and contaminants should be properly disposed of, and the recovery equipment should be cleaned and stored properly.
VEVOR RR500 Refrigerant Recovery Machine
Overall, proper refrigerant recovery is an important process for protecting the environment, complying with regulations, and reducing costs associated with refrigerant replacement. It’s important to follow proper procedures and regulations when recovering, storing, and disposing of refrigerants.
It’s important to note that refrigerant recovery should only be performed by trained professionals who have the proper equipment and knowledge of regulations. Refrigerants are harmful to the environment and can cause harm if not handled properly.
Here are some key considerations for refrigerant recovery.
Safety: Refrigerants can be hazardous to human health and the environment, so safety should be the top priority during the recovery process. Technicians should wear appropriate personal protective equipment, and the recovery equipment should be well-maintained and tested for leaks. The Vevor refrigerant recovery tank is included with a pressure relief valve that will automatically relieve any pressure exceeding the tanks working pressure. The Vevor refrigerant recovery machine RR500 has an intake and discharge gauge that allows you to always observe the pressures. It includes a high-pressure cut-off switch that automatically shuts down the machine if the internal pressure is higher than 558 psi to ensure secure operation.
The Vevor RR500 automatically shuts off if pressure reaches 558 psi
Technicians serving AC and refrigeration equipment must pass a certification exam to maintain, service, repair, or dispose of appliances containing refrigerants.
Recovery Equipment: The recovery equipment used should be compatible with the type of refrigerant being recovered. The equipment should also be properly sized for the system being serviced, and technicians should follow the manufacturer’s instructions for its use. The Vevor 30 lb. capacity refrigerant recovery tank can handle a wide range of refrigerants including R134A, R-22, R-12, R410A, R404A, R502, R1234YF, and R32.
Recovery Techniques: There are two primary techniques for refrigerant recovery: liquid recovery and vapor recovery. Liquid recovery is used for systems that have a high percentage of liquid refrigerant, while vapor recovery is used for systems with mostly vapor refrigerant. Technicians should be trained in both techniques and choose the appropriate method based on the system being serviced. The Vevor RR500 recovery machine can quickly recover vapor and liquid refrigerants using a maximum recovery speed of 1750 rpm.
There are three valves on the Vevor RR500 refrigerant recovery machine that provides multiple adjustment modes including liquid recovery, vapor recovery and self-purge modes.
Vevor RR500 Recovery Machine can Recover Vapor and Liquid Refrigerants
Record-Keeping: Proper documentation is important for tracking the amount and type of refrigerant recovered. Technicians should keep accurate records of the amount of refrigerant removed, the type of refrigerant, and the date of recovery.
Recycling or Reclamation: Recovered refrigerant can be recycled or reclaimed for reuse in other systems. Technicians should follow EPA guidelines for handling, storing, and transporting recovered refrigerant for recycling or reclamation. Recovered refrigerant may not be resold unless it has been reclaimed by a certified reclaimer or is being transferred to equipment belonging to the same owner.
Disposal: If refrigerant cannot be recycled or reclaimed, it must be properly disposed of according to EPA regulations. Technicians should follow the guidelines for disposal and keep accurate records of the amount and type of refrigerant disposed of.
Environmental Protection: Refrigerants such as CFCs, HCFCs, and HFCs are known to deplete the ozone layer and contribute to global warming. Proper recovery and disposal of these refrigerants helps to protect the environment and prevent the release of harmful gases into the atmosphere.
Legal Compliance: In many countries, it is illegal to release refrigerants into the atmosphere. Proper recovery and disposal are required by law to comply with environmental regulations so make sure you use a recovery machine and recovery tank like the ones provided by Vevor. Section 608 of the EPA’s Clean Air Act prohibits the knowing release of refrigerant during maintenance, service, repair, or disposal of air conditioning and refrigerant equipment.
Cost Savings: Recovered refrigerants can be recycled and reused, which can result in cost savings compared to purchasing new refrigerants. The cost of refrigerants has increased dramatically with the phaseout of production of some refrigerants.
Portable and Handy: The Vevor RR500 refrigerant recovery machine is compact and lightweight making it convenient to carry or roll around using the trolley handle and wheels.
The Vevor RR500 is convenient to carry or roll around with a trolley handle and wheels
Overall, proper refrigerant recovery is essential for the safe and efficient operation of refrigeration and air conditioning systems. Technicians should follow best practices for safety, equipment, techniques, record-keeping, and proper handling of recovered refrigerant.
Daylighting for Health and Energy Savings. In this article we’ll discuss the many benefits of daylighting including improved health and energy efficiency. However, we’ll cover why it’s important to design and implement daylighting strategies carefully, considering factors such as building orientation, climate, and occupant needs, to ensure optimal performance and maximum benefits.
In the U.S. the location of windows is important for implementing daylight saving strategies while preventing excess heat gain in summer months. According to the Department of Energy (DOE), windows that are located on the South side of a building provide the most light in winter months, while minimizing direct sunlight during the summer to keep the interior cooler. Windows located on the north of the building are also beneficial for bringing in natural light with little glare and little summer heat. Orientation of the building should be optimized to avoid windows on the east and west sides of the building as they don’t work as well for daylighting because of excess heat gain and glare during the summer months.
How to Increase Daylighting while reducing glare
To increase daylighting while reducing glare, you can implement various design strategies and use appropriate materials. Here are some suggestions:
Use light-colored or reflective surfaces: Light-colored walls, ceilings, and floors can help distribute natural light more effectively throughout a space. Reflective materials, such as glossy finishes or mirrors, can bounce light deeper into the room.
Install windows with appropriate glazing: Consider using windows with glazing that reduces glare while allowing ample natural light to pass through. Low-emissivity (Low-E) coatings on window glass can help to control the amount of visible light and heat transmitted while minimizing glare.
Utilize shading devices: Implement window treatments like blinds, shades, or curtains that can be adjusted to control the amount of sunlight entering a room. Tilted blinds or louvers can redirect light towards the ceiling, creating a softer, indirect illumination.
Incorporate light diffusers: Light diffusers, such as frosted glass, prismatic panels, or light shelves, can scatter and disperse natural light, reducing direct glare while still maintaining a high level of daylighting. They help to create a more evenly distributed illumination.
Optimize interior layout and furniture arrangement: Arrange workstations or seating areas in a way that allows natural light to reach deeper into the space. Avoid placing desks or seating directly in the path of strong sunlight to minimize glare.
Use adjustable lighting systems: Combine artificial lighting with daylighting by incorporating adjustable lighting systems. Dimmable lights or those with occupancy sensors can help balance artificial and natural light levels throughout the day.
Consider exterior shading elements: Exterior shading devices such as overhangs, awnings, or fins can effectively block direct sunlight and reduce glare. These elements can be designed to allow low-angle sunlight to enter the space while blocking high-angle sunlight.
Implement light redirecting techniques: Light redirecting films or glazing can be applied to windows to diffuse and redirect sunlight, reducing glare while maintaining a high level of daylighting. These films can help distribute light more evenly and prevent harsh reflections.
Use daylighting analysis tools: Computer simulations and daylighting analysis tools can help optimize the design by modeling how natural light will interact with the space. These tools can assist in identifying potential glare issues and refining the design to maximize daylighting while minimizing glare.
Remember, the specific strategies to implement will depend on factors such as the building’s orientation, location, and the desired level of daylighting. Working with a professional architect or lighting designer can provide more tailored solutions to address your specific needs.
Health Benefits of Daylighting
Daylighting, which refers to the use of natural light to illuminate the interior of buildings, has been shown to have several health benefits. Here are some of the ways in which daylighting can be good for your health:
Patient Rooms: In the design of hospitals there is a requirement that all patient rooms are provided with a window, as research has shown that patients exposed to natural daylighting have faster recoveries with less medication.
Reduces stress and improves mood: Exposure to natural light has been linked to increased production of serotonin, a neurotransmitter that helps regulate mood. Exposure to natural light has been shown to reduce stress and anxiety levels. This is because natural light can help regulate your body’s levels of the hormone cortisol, which is often referred to as the “stress hormone.”
Improves sleep and Mental Clarity: Exposure to natural light during the day can help regulate the body’s circadian rhythm, which is the internal “clock” that helps regulate sleep and wake cycles. This is because natural light helps your body produce the hormone melatonin, which is important for regulating sleep. This can lead to better sleep at night, which is essential for overall health and well-being.
Enhances vision: Natural light is typically much brighter and more evenly distributed than artificial light, which can help reduce eyestrain and improve visual acuity, making it easier to see details and colors.
Increased comfort: Spaces that are well-lit with natural light are typically more comfortable and enjoyable to work in than those that are poorly lit with artificial light. This can help improve morale and motivation.
Increased Productivity and Reduced absenteeism: Studies have shown that workers in spaces with natural light are less likely to take sick days, and that people who work in well-lit environments are more productive and make fewer errors than those who work in poorly lit spaces.
Saving Energy with Daylighting
Daylighting can save energy by reducing the need for artificial lighting and by decreasing the amount of energy needed to cool a building. Here are some ways in which daylighting can help save energy:
Reduced need for artificial lighting: By incorporating daylighting strategies such as windows, skylights, and light shelves, natural light can be used to illuminate the interior of a building during daylight hours. This can reduce the need for artificial lighting, which is typically one of the largest energy consumers in a building.
Use of daylight-responsive lighting controls: Daylight-responsive lighting controls can be installed to automatically adjust artificial lighting levels in response to the amount of natural light in a space. This can help ensure that artificial lighting is only used, when necessary, further reducing energy consumption.
Lower cooling costs: Traditional electric lighting can produce significant amounts of heat, which can increase cooling loads and energy consumption. By using natural light instead of electric lighting, less heat is generated, which can reduce the need for air conditioning and lower cooling costs while saving energy.
Improved thermal comfort: Daylighting can also improve thermal comfort by reducing temperature fluctuations and creating a more pleasant and comfortable environment. When occupants are comfortable, they are less likely to adjust the thermostat or use additional energy-consuming devices to regulate the temperature.
Here are the basic steps of how daylighting works:
Sunlight enters the building through windows, skylights, or other openings in the building envelope.
The light is then diffused and dispersed throughout the space using various materials, such as light shelves, louvers, or prismatic glass, to reduce glare and create a more even distribution of light.
The daylight is then directed to where it is needed most, such as workstations, classrooms, or living spaces, using reflective surfaces and other design features.
To maximize the benefits of daylighting, it is important to control the amount of light entering the building, especially during times of the day when the sun is most intense. This can be achieved through shading devices, such as blinds or exterior shading structures, or using automated lighting controls that adjust artificial lighting levels in response to the amount of natural light present.
How daylighting effects student performance
Daylighting can have a positive impact on student productivity in several ways:
In addition to the health benefits mentioned previously, here are some further notes as it relates to students and natural daylight.
Improved academic performance: Studies have shown that students who learn in well-lit environments perform better academically than those who learn in poorly lit spaces. This may be due in part to the fact that natural light can help improve cognitive function, including memory, attention, and decision-making.
Reduced behavioral issues: Natural light has been linked to reduced stress and improved mood, which can help reduce behavioral issues in the classroom. When students are in a better mood and less stressed, they are more likely to be engaged in their work and less likely to exhibit disruptive behavior.
Reduced absenteeism: By creating a more comfortable and healthy learning environment, daylighting can help reduce absenteeism and improve overall attendance rates. When students are exposed to natural light during the day, it can help keep them alert and awake, which can reduce absenteeism and improve attendance.
Overall, daylighting can have a positive impact on both physical and mental health, making it an important consideration when designing and constructing buildings. By creating a comfortable and healthy work environment, daylighting can help employees feel more engaged, alert, and productive. Employers can potentially improve the bottom line by increasing productivity and reducing absenteeism and turnover By incorporating daylighting into building design. Daylighting can be an effective way to save energy in buildings by reducing the need for artificial lighting and decreasing cooling loads. By incorporating daylighting strategies into building design, building owners and managers can potentially reduce energy costs and environmental impact while creating a more comfortable and healthy work or living environment.
How to size plumbing water pipes using fixture units. Plumbing codes use various methods to determine the size of the water piping feeding a building. One of those methods is to use Fixture Units. To figure water supply fixture units, you need to calculate the demand load that plumbing fixtures will place on a water supply system. Here are the 14 steps required to size domestic water mains and distribution piping along with how to determine fixture units and the volume of water required.
Step #1 – Figuring Total Water Supply Fixture Units (WSFU’s)
Identify the different types of plumbing fixtures that will be connected to the water supply system. Examples of common fixtures include toilets, sinks, bathtubs, showers, dishwashers, and washing machines. We’ll use a 3-story office building for our example. Here we show that each floor has four water closets, three urinals, and three lavatories.
Plumbing Water Supply Fixture Unit Values for Plumbing Fixtures
Determine the water supply fixture unit value of each type of fixture. Water supply fixture unit (WSFU) is a measure of the flow rate of water through a specific fixture. The WSFU of a fixture can be found in the plumbing code or by consulting a plumbing engineer. Here we show several different codes and the various tables they use for fixture unit values.
Each code will have a procedure for calculating the required flow rates based on the type and quantity of fixtures. Here we use the 2021 International Plumbing Code Table E103.3(2) for our example. The table shows that a public “Lavatory” has 1.5 fixture units, and a public “Urinal with a 3/4” flushometer valve” has 5 fixture units, and a public “Water Closet with flushometer valve” has 10 fixture units.
Multiply the WSFU of each fixture by the number of fixtures of that type. This calculation will give you the total fixture units (WSFUs) for each fixture type.
For our example, there are three lavatories per floor, times three floors, which equals a total of 9 lavatories and based on 1.5 WSFU each, there would be a total of 13.5 fixture units for the lavatories.
There are also a total of 9 urinals with a value of 5 fixture units each. The total fixture units for all the urinals are 9 times 5 = 45. Then there are 4 water closets per floor times three floors, for a total of 12 water closets. The WSFU for a water closet with a flushometer valve is 10, which would give us 12 x 10 = 120 fixture units.
Add up the WSFUs for all fixtures in the building or plumbing system to get the total WSFUs for that system. This will include adding up the total fixture units for each branch and riser. What we haven’t considered is any water flow demands for cooling towers, RO systems, Process Equipment, or landscaping. The plumbing engineer will need to work with the other trades to determine their needs for water. In our example we have a total of 13.5 WSFU’s for lavatories, 45 for urinals and 120 fixture units for water closets, for a total of 178.5 fixture units.
Total Plumbing Water Supply Fixture Units (WSFU) for 3-Story Example
Step #2 – Determine the Water Flow (GPM) or (L/m)
Determining the water flow involves finding the total Water Supply Fixture Units in the very left column of IPC table 103.3(3), then moving along that row to the intersection of the demand column for “Supply Systems for Flushometer Valves”. The Total Fixture units are close enough to 180 so the use of this row is fine. This gives us a water flow of 85.5 GPM or 323.6 liters per minute.
Step #3 – Obtain Minimum Daily Static Pressure Available
The available static pressure in psi or kPa at the water meter or source of water supply is provided by the City or local water authority. The minimum pressure is used in the calculations to ensure that during peak water usage season, pressure is available to operate the most demanding fixture.
Peak water usage usually occurs in summer when landscaping systems are maximized, and water-based cooling systems are utilized at their peak. It is essential that sufficient water pressure be available to overcome all the plumbing water system losses due to friction and elevation so that plumbing fixtures operate properly. For our example we’ll use 70 psi or 482 kPa.
Step #4 – Pressure Loss due to Building Height
To get the flow of water needed for the building there needs to be enough pressure left over after subtracting for all of the losses that occur due to various reasons, the first is the height of the building. Water exerts a pressure of 0.433 pounds per square inch for every 1 foot in height, or 9.81 kPa per meter.
Steps for Calculating Main Domestic Water Piping Size
The pressure coming from the city will be reduced by the loss occurred from this column of water sitting in the pipe risers feeding the building. In our example (see image above) the building is three stories high and has a 35 foot (10.6m) riser. To determine the loss of pressure from this column of water the following equation is used.
Riser Height in Feet (Meters) x Pressure loss per Foot (Meter)
35 Feet x 0.433 = 15.2 psi or
10.6 meters x 9.81 kPa = 105 kPa
Step #5 – Minimum Pressure required at Remote Fixture
This is to ensure that the fixture has enough pressure to operate properly. Each fixture requires different amounts of pressure to operate, so it’s important to pick the remote fixture that requires the greatest pressure to produce a flow.
IPC Table 604.3 for Minimum Pressure Requirements.
Using IPC table 604.3 the siphonic water closet with a flushometer valve needs 35 psi or 241 kPa for proper operation.
The friction loss or pressure loss through the water meter can be found from the manufacturer of the water meter. In our example we’ll use 6 psi or 41 kPa for the pressure loss through the meter.
Step #7 – Pressure loss through Backflow Preventer
The use of a reduced pressure backflow assembly (RPZ) is to prevent dirty water from reversing flow and contaminating the clean water supply. If required then the pressure drop needs to be included in the calculation for total pressure loss. In our example the pressure drop is 4 psi or 28 kPa.
Step #8 – Pressure loss through Pressure Regulating Valve
The IPC restricts excessive water pressure by requiring a pressure regulating valve when the pressure exceeds 80 psi (552 kPa). The reason is to reduce the incident of water hammer, reduce the excessive loss of water from pressure relief valves, and for the protection of equipment and fixtures. Since the maximum water supply in our example is less than this, there is no need for a PRV.
Step #9 – Total Pressure required for Operation
Add up all the pressure losses and the required minimum water pressure at a remote fixture with the highest requirements. Adding Steps #4 through #8 in our example equals 60.2 psi or (415 kPa). This is the total pressure required for proper operation, but not including the required pressure drop caused by the water flowing through the pipe and fittings.
Plumbing Water Pipe Size Calculation Steps
Step #10 – Pressure available for Friction Loss
Subtract all the losses in Step #9 from the minimum available pressure in Step #3. If the available pressure is 70 psi or 482 kPa, then our calculation looks like this. 70 psi – 60.2 psi = 9.8 psi, or 482 kPa – 415 kPa = 67 kPa, this is the amount of pressure left over for the resistance to flow that is needed to move the required GPM or LPM to the most remote fixture.
Step #11 & 12 – Total Developed length of Piping
This is the developed length of the water piping between the water source and the most remote fixture times 1.5 to account for pressure loss through fittings and valves. Fittings and valves add 50% to your total length, but this could vary based on design. In the example here there is a total of 140 feet or 42.6 meters from the water source to the most remote fixture. The calculation would be 140 feet x 1.5 = 210 feet, or 42.6 meters x 1.5 = 63.9 meters of total developed length.
If you know the exact amount of fittings and valves then table E103.3(6) in the IPC could be used to determine the equivalent length for each size and type of fitting or valve.
Step #13 – Determine the Friction Loss per 100 Feet
This calculation determines the leftover pressure in the system that can be used to overcome the pressure loss due to friction in the pipes and fittings. Step #10 shows that there is 9.8 PSI or 67 kPa for friction loss.
The calculation would be (9.8 psi/210feet) x 100 = 4.7 psi/100 feet
Step #14 – Determine Size of Water Service Pipe
This is where the size of the main is determined using the information that we have put together so far.
Using IPC Table 103.3(3) for Friction Loss in Smooth Copper Tubing
Using Figure 103.3(3) we enter the total GPM of 85.5 and our allowable pressure drop of 4.7 psi/100 feet and they intersect just above the 2” pipe line, so to be safe we’ll specify a 2-1/2” or 65mm pipe.
Plumbing Water Supply Fixture Unit Calculation Totals for Water Pipe Sizing
If we found out through our analysis that there wasn’t enough water pressure from the city to overcome all of the pressure losses and provide the minimum required pressure at the most remote plumbing fixture, then a booster pump would be considered.
How to size Plumbing Water Pipes using Fixture Units
