With few exceptions, the water demands of a Commercial Building are significantly overestimated, which has negative impacts on the long-term performance, reliability, and efficiency of a Booster System.  At Cougar USA, we design our systems to be most efficient at the partial load of the building, which improves performance & reliability and reduces operating costs.  In this Tech Talk, we cover the pump and system selection for Booster Systems.

Make sure to check out Parts I & II!

Pressure Boosting Systems – Selection – Part 3 Tech Talk Transcript:

Hi, I’m Tim Zacharias with Cougar USA, on this Tech talk we’re going to be going over system selection for pressure-boosting systems in commercial building applications. This is part three of a three-part series. So please check out Parts one and two if you haven’t already.

The primary purpose of a Pressure Boosting System is to maintain constant pressure in the building (surprising, right?!).  In Part II of this Tech Talk, we explain the factors to consider when determining the pressure requirements for a building. 

Pressure Boosting Systems – Pressure – Part 2 Tech Talk Transcript:

Hi, I’m Tim Zacharias with Cougar USA. On this Tech talk, we’re going to be talking about calculating the system pressure required for a pressure boosting application of a commercial building. This is part two of a three-part series, so if you haven’t seen part 1 on the flow calculation, make sure to check that one out as well.

Pressure Boosting Systems are essential for delivering water to high-rise buildings; however, the method for sizing these systems has not changed significantly in over 50 years!  Cougar USA’s High-Performance Design approach combines our extensive knowledge & experience with the best products on the market to deliver systems that provide constant water pressure with little to no downtime and the lowest Life Cycle Cost.  Check out this three-part Tech Talk series on Booster System Design to see how we do it.  We will cover the flow and pressure requirements of a building and pump & system selections to meet them.

Pressure Boosting Systems Design Part 1 Tech Talk Transcript:

Hi, I’m Tim Zacharias with Cougar USA on this Tech talk, this will be the first of a three-part series for sizing and selecting pressure boosting systems. On this one, we are going to be looking at the flow rate for a commercial building.

Now, a couple of different things that we need to take into account when we are looking at flow. The first place that we can start is Hunter’s curve in the fixture unit counts. This is a method that goes back to the 1960s. Basically, we can count up our fixture units in the building, look at the chart for what that says the equivalent flow rates are, and what that is going to give us is our worst-case flow rate for that building.

A High-Performance Water Pressure Reducing (PRV) Station requires valves that are properly sized for the flow rate and pressure drop of the zone they serve.  Also, the High Flow and Low Flow valves must have the proper pressure setpoints to balance the flow rates across them.  Cougar USA can help in the design, installation, and start-up of PRV’s to ensure constant pressure to the fixtures downstream of the PRV Station.

Water PRV Sequence of Operation Tech Talk Transcript:

Hi, I’m Tim Zacharias with Cougar USA on this Tech Talk, we’re going to be covering the sequence of operation for a Water Pressure Reducing Valve station or PRV station.

For this example, we are looking at a PRV station here that’s designed for a high-rise building. We’re generating a lot of pressure with our booster system, down the lower floor to be able to have usable pressure up at the top of the building, and in the lower floors, we’re having to knock that pressure back down to get it below 80 PSI.

Storm Sump Pump Stations protect the lower levels of buildings and parking garages from flooding.  Check out this Tech Talk on the application and design of Storm Sump Pump Stations.

Storm Sump Pump Stations Tech Talk Transcription:

Hi! I’m Tim Zacharias with Cougar USA. In this Tech Talk, we’re going to cover storm Sump Pump Station applications.

So when we’re looking at a storm sump application this is going to be anything in a building that’s collecting water from a clean source, rain, groundwater, condensate from Air Handlers, or fan coil unit, things like that. And it’s going to be in the typical locations in a building: at basement, parking garage, loading docks, spots where the water’s going to collect. We are typically going to recommend in this situation an N+1 design, meaning, both pumps can handle, one hundred percent of the load coming into the Basin. But in Houston, unfortunately, we have these high rainfall events where it might be normal or require two pumps to run in certain situations, so that’s going to affect the type of float switch assembly that we use and some of the programming so that we can run those two pumps with or without alarms.

Rain isn’t the only way a building can flood. If there are Domestic or Fire Water Storage Tanks in the building, a flooding risk is always present.

Cougar Systems Level Controls constantly monitor for High Level and actuate a motorized valve to shut off the water supply to prevent overfilling the tank and flooding the space. 

Flood Protection Valve Tech Talk Transcript:

Hi, I’m Tim, Zacharias with Cougar USA. In this Tech Talk, we will cover flood protection valves for fill stations and atmosphere storage tanks. In the city of Houston, we have the requirement to go through the atmosphere storage tank before we add booster pumps into our building. So, a lot of these are going to be installed on the first floor, maybe in a basement on a vault outside, and we want to prevent those tanks from overflowing and flooding the building.

In the city of Houston, we’ve had two major interruptions in water supply in the last 18 months. Unfortunately for many buildings, they didn’t find out until their tank and piping were dry and it was too late to act.

With a Level Control Panel from Cougar USA, you can monitor incoming city water pressure and receive an alarm as soon as the pressure drops, giving you time to conserve water and warn patients, tenants, and guests of the situation.

Monitor City Pressure on Fill Stations Tech Talk Transcript:

Hi I’m Tim Zacharias, with Cougar USA. In this Tech Talk, we’re going to cover Monitoring City Pressure on your fill station so when you have a flooded suction application, like in the city of Houston, where we have the code requirement to go through an atmosphere storage tank, like this before your booster pumps.

Fill Valves are the heart of a tank-level control system (making the control panel the brain).  There are two common types of fill valves, Float, and Electronic, used in commercial building tank fill applications.  While both can be effective, the electronic float valves (and paired controls) provide extended life through even wear, improved communication with the BAS, and ease of service. 

On this Tech Talk, we are going to cover the difference between the float style and electronic style fill valves for storage tanks. So in the city of Houston we have this code requirement where you have to go through an atmospheric storage tank before you add on a pressure boosting system.

To pressurize your building, you got two options on which type of fill valves, you would use for that tank. The style that’s been around for a long time, is going to be this one 2401 float valve from Cla Val using the 100-01 Hytrol valve, base valve configuration and we’ve got this CF1C1 Pilot assembly here that is controlling the water on, and off the valve to open and close it.Now, this is a mechanical assembly you got the float hanging down in the tank and literally just like the back of a toilet, you know, the float goes up the valve is going to turn off the flow goes down the valve is going to open up and refill the tank. Problem with these style valves is it’s mounted up on top of the tank it can be difficult and even dangerous to get in and service it and it’s all mechanical in terms of how you make any adjustments, how it turns on and off and when you have two of them, there’s no way to alternate which valve is the lead valve.

We are excited to announce the promotion of Tim Zacharias to President of Cougar USA!  Tim has been with the company since 2007, having worked in various roles, most recently as Chief Operating Officer since 2017. 

Mike Zacharias has served as President since co-founding the company in 2003 and will continue to work with Cougar in sales and as Chairman of the Board.  Scott Magee, co-founder, will continue his role as Vice President and as a member of the Board of Advisors. 

The Leadership Team has expanded to include three new members.  Randy Milian and Steve Hale both join as Operations Managers of Cougar Sales and Cougar Systems, respectively.  Both are exemplary members of the Cougar Family, and we are excited to see the new insight and perspective they bring to the Leadership Team!

June 1st marks the beginning of Hurricane Season, and the NOAA predicts 2020 will be busier than average.  While many property & facility managers are still working through the building operations changes required due to COVID-19, there are some additional measures to consider in preparation for potential heavy rains and flooding.  The National Weather Service and FEMA have guidelines for the overall planning, so we will highlight a few items specific to water systems in commercial buildings.

Before the Storm

It is critical to regularly perform Preventive Maintenance (PM) on Storm Sump Pump Stations to ensure their performance.  A PM should include a visual inspection of the sump basin, verifying the operation of each pump, and the control panel.  Cougar USA now offers Preventive Maintenance programs on Sump Stations, as well as other water control systems.

During the Storm

If you have an issue during a storm, Cougar USA Technical Support and Service can be reached 24/7 at 832-678-3930.  We help troubleshoot issues over the phone and with our Remote Guidance App that allows us to see what you see in real-time. 

To maintain water quality, a building’s water systems need to be flushed and tested.  Opening faucets, showers (hot & cold), flushing toilets, draining dead legs, running drinking fountains & bottle fillers, ice machines, coffee makers, and other appliances on a regular schedule will prevent the water from becoming stagnant and potentially allowing bacteria growth.  If any of these fixtures drain to a sanitary sump station, it needs to be pumped down on a similar schedule to prevent water from sitting in the basin for long periods.  The schedule for flushing building’s water systems will vary depending on occupancy, size, age, and design.

Regular water testing will provide feedback on the building’s water quality.  Cougar USA can provide on-site Legionella testing Spartan Bio Cube and deliver results in 45 minutes.  If Legionella is detected in the water, we can provide recommendations for short-term remediation and long-term mitigation. 

At this point, you have received multiple emails regarding companies’ response to COVID-19, so this will be a brief update on how Cougar USA can be of service moving forward. Our first priority is the safety of our employees, partners, and customers, and we will adapt to the changing situation to serve our customers the best we can.

Our office, warehouse, and panel shop are open with normal hours, but we will be limiting activities such as in-person training (more on that below). We will have a portion of our team working remotely; however, this will be seamless for you as we are using cloud-based communication systems.

Our service techs and sales team are available for site visits and will take all necessary precautions while on site.

Reopening buildings that have been unoccupied or under-occupied for the last 30-60 days may create some water quality issues you may need to address. Here are some resources to help this transition as smooth as possible:

Webinar

We recently hosted a webinar with Patrick Verwys from Triple Clear where he explains the potential water quality issues and how the Force Field filter technology can help in multiple applications when reopening buildings.  Watch the webinar here.

Guides

Mike Fehr (owner of Fehr Solutions, an independent water consultant), created two checklists that outline a detailed plan to identify systems, how to flush and/or change filters, and how to test the results to ensure the system is clean. Click below for the guides on Potable and Non-Potable water systems.

Water is the Life Blood of commercial buildings, used for consumption, comfort heating & cooling, and patient care & sterilization in Hospitals. Disruptions in the city water supply can cause major issues from building closures to damaged equipment. Here are some ways to protect your building before, during and after losing the city water supply.

Monitor City Pressure

The City of Houston has a unique amendment to the UPC that requires an atmospheric storage tank of water before adding pressure boosting pumps. During an outage, the tank water level will be drawn down by consumption in the building, mainly the cooling tower make-up, and eventually, the tank and your piping will go dry because the tank level is not restored by city water. Getting a low city water pressure alarm from your tank level control panel allows you to take action and reduce water consumption before the tank and piping run dry.

Monitor Storage Tank Levels

Many storage tanks in Houston use Float Style valves to make up the water in the tank. These are mechanical valves that do not require a control panel to operate them, however, a simple Tank Level Alarm Panel can monitor the tank level and provide feedback to the Building Automation system in the event of a High or Low-Level Alarm. The Level Alarm Panel also can be used to protect your Booster Pump System from running dry through a Pump Low-Level Cutoff output. Without monitoring city pressure and/or tank water levels, there is no way to know there is an issue until it’s too late.

For a pump system to perform a low-flow shutdown, it must first be able to measure the flow demands in the system. Flow Switches and Flow Meters are mechanical means of measuring flow, which can work, but both require proper installation in the system piping for proper readings. Space and piping constraints can limit the installation of switches or flow meters.

The outlet pressure is determined by two factors. First is the number of floors the PRV Station is serving, and the second factor is whether the station is feeding the floors above or below the station. A good rule of thumb is that each floor will result in a pressure change of 5 PSI. If the floors fed by the PRV Station are the floors above, then you would need a higher outlet pressure at the PRV Station (around 65 to 75 PSI) because the pressure will drop about 5 PSI each floor higher in the piping. If the PRV Station is feeding the floors below, the outlet pressure would need to be lower (around 40 to 50 PSI) because the pressure will increase 5 PSI for each floor lower in the piping.

High-rise buildings present multiple challenges for water distribution due to the high pressures required to reach the top of the building. The high pressures in the lower levels of the building cause high-pressure drops across Pressure Reducing Valves (PRVs), over 100 PSI or more, creating the potential for cavitation within the valves.

Cla-Val explains cavitation in this white paper, saying “Cavitation occurs when the velocity of the fluid at the valve seating area becomes excessive, creating a sudden, severe reduction in pressure that transforms the fluid into a vapor state, resulting in the formation of literally thousands of minute bubbles. The subsequent decrease in velocity and pressure rise that occurs after the valve seating area, when the pressurized condition resumes, causes these vapor bubbles to collapse at the rate of many times per second. Should this occur in close proximity to any metal surface, damage can take place. Over time, this can lead to valve failure.”

The damaging effects of cavitation include excessive noise, erosion of the valve and eventual valve failure. When designing a system with pressure drops greater than 100 PSI, there are two ways to avoid cavitation.

Mission

At Cougar USA we are proud to provide complete, tailored solutions for our customers. We have the technical knowledge and experience to identify their needs, wants and potential issues. We also help design, deliver and support a complete solution. Every day, Cougar supports Consulting Engineers, Installing Contractors and Building Engineers, especially after hours and weekends for emergencies. We continue to serve our customers long after the initial sale. This level of service and quality of products build trusting, long-term relationships with our customers and partners.

Cougar USA makes buildings work, so the people inside can do theirs.

People trust our Water Control Systems to deliver efficient, reliable solutions for plumbing and mechanical applications in commercial buildings.

Our systems play an important role in the operations of hospitals, hotels, Schools, universities, commercial office buildings and event centers. Cougar is proud to serve Houston’s best buildings and institutions like Minute Maid Park, NRG Stadium, George R. Brown Convention Center, The Post Oak Hotel, The Houstonian, JPMorgan Chase Tower, Capital Tower, Heritage Plaza, Texas Children’s Hospital, MDACC Cancer Center and hundreds of others.

The Houston Amendments to the Uniform Plumbing Code Table 607.7 has specific guidelines for tank overflow and vent sizing, so in the event of a valve failure, the excess water will flow through the overflow to a floor drain. Especially on a fire tank system with large fill valves, this can be up to 1,000 gallons per minute of water pouring onto the floor of the pump room. Even when properly sized, floor drains may not handle this sudden demand (trash, etc.), and water can flood the pump room.

Many commercial buildings use storage tanks for Domestic (Potable) and Fire Water Applications, especially in Houston where it is required by Houston Amendments to the Uniform Plumbing Code Section 607. As water is used in the building, an automatic system is required to replenish the water and maintain a constant level in the tank. In domestic applications, this process can repeat multiple times an hour during peak demand loads. An automatic level-control system has two main components, Fill Valves and Controls.

Float Controlled Valves (Cla-Val model 124-01) are widely used on break tanks in commercial buildings. Float valves operate on the same principle as the valves in the back of a toilet: a float attached to a rod moves up and down with the level of the water in the tank. Float valves are simple and effective, but there are drawbacks in commercial applications. Most valves are installed on the top of tanks with the float rod directly attached to the valve, making them difficult to access and maintain. Tank-water-level adjustments are also difficult because the float rod length and float position must be changed on the valve itself.

When two float valves are used, there is no alternation between valves. The lead valve (shorter float rod) will always operate first, with the lag valve going long periods without use. This combination will eventually cause failures in both valves without proper preventative maintenance. Also, these systems typically provide little or no feedback to the Building Management System.

Pressure Boosting System Design has also seen drastic changes in the same time period. Fifty years ago, large constant-speed, single-stage, centrifugal-pump systems were the design standard. These workhorses run 24/7, 365 days a year, regardless of the system demand in the building. This results in wasted energy and unnecessary wear on the pumps and piping. With smaller flow demands today, older pumps still in service are grossly oversized, making them much less energy-efficient.

More than 60 years ago, the late Dr. Roy B. Hunter developed a system for calculating water loads in commercial buildings. The estimated water demand of fixtures (water closets, sinks, etc.) is given a value called Fixture Units which have an equivalent demand load in Gallons Per Minute (GPM). The Fixture Units and Demand Load relationship is known as Hunter’s Curve and is still the basis for plumbing system design today.

Hunter’s Curve can be effectively used to calculate total system demand, but it has a glaring flaw. There is no consideration for diversity in the system demand. Using Hunter’s Curve for the basis of design of a Pressure Boosting System results in a pump system sized for all fixtures being used simultaneously, a scenario that will likely never happen. The pumps are grossly oversized for partial-demand conditions which make up 90% or more of total operation, causing poor system control and unnecessary wear on the pumps and piping system. In addition to Hunter’s Curve, Cougar USA uses field experience and data collection for system design.

To generate an accurate demand load profile, we gather as much information as possible about the building. The type of building has a huge impact on the load profile; even with similar fixture units, hospitals, hotels, schools, and office buildings will all have different load demands throughout the day and week. Special applications, the height of the building, locations of equipment, and potential future expansion are all factors in creating the right Building Load Profile. Once the system requirements are determined, we must make the right equipment selection.