Application Tips
From installation guides to product information, find the resources you need for your specific applications. For an overview of all our products by complimentary product visit the HVAC 101 brochure.
Breweries, Wineries, and Food Processing
For over 60 years, Griswold Controls has provided stainless steel automatic flow limiting valves to breweries and food processing plants to maintain constant flowrate helping them make food and beverages, as well as help clean equipment.
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Pressure Testing with Air Versus Pressure Testing with Water
Pressure Testing with Air versus Pressure Testing with Water to detect leakage is a common practice in our industry. We are often asked why air testing must be done at lower pressures than water testing. To find leaks, a low pressure (30-50 PSI) air test is just as effective as high pressure (150 PSI) water test. This is because the viscosity and surface tension of water is greater than that of air. For example, the viscosity of water is about 89 times greater than the viscosity of air...
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Greenhouse Facilities
Griswold Controls Pressure Independent Valves and Actuated Valves have been installed for years in greenhouse facilities around North America to help improve the growing conditions inside. Controlling the temperature in this facility is crucial to maximize a plant’s health and growth rate. The ambient temperature for plants directly impacts the plant’s which affect the quality of the final product so it is critical that the hydronic HVAC systems maintain temperature within a narrow range in the most cost efficient method possible.
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3-Way Control Valves or Pressure Independent Valves?
A 3-way control valve shuts off water flow in one pipe while opening water flow in another pipe. In a modulating or 3-point floating application the valve can also mix water from two different pipes into one pipe or divert water from one pipe into two different pipes. Connected to the Building Automation System and thermostats located in each zone, the 3-way valve directs the heating or cooling water through the coil if heating or cooling is required. If the zone does not need heating or cooling the flow is directed through the bypass line to the return piping. This means the flowrate will stay the same if you use 3-way valves in a system. In comparison a 2-way valve can stop water flow to the coil when there is no need for heating or cooling. This means the flowrate will vary if you use 2-way valves in a system.
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Chilled Beam Systems
“Hot air rises,” he grumbled as he climbed the ladder toward the ceiling, his boot tips clicking on each rung of the ladder like an old antique typewriter. “Excuse me?” she said, wondering if he was talking about the actual hot air in the room, rising toward the chilled beam, or perhaps he was eluding to her constant talking for the last hour as they walked the building and inspected each chilled beam? The fan grew subtly louder as the chilled beam cover was opened to reveal the coil, but then the quiet peace was shattered by an alarm sounding from the Building Management System…
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Cooling Computer Data Centers for Decades
Heat may be your friend on a tropical vacation but in a computer data center, heat is your number one enemy! Griswold Controls valves have been used in cooling computer data centers all across the country to help the HVAC system remove that computer-crippling heat. They also have year-round cooling requirements due to the high volume of computer equipment like servers generating tremendous amounts of heat; the load can be six times the cooling requirement of a traditional office building. Unlike most HVAC systems where comfort is the primary objective for design, engineers designing to cool computer data centers have additional details to consider that impact the life and performance of the computer equipment. Therefore it’s critical that these systems operate with consistent high performance in the most cost-efficient method possible.
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Piping Pressure Independent Valves in Parallel for Greater Flows
The Pressure Independent Valves, PIC-V and MVP, can be piped in a parallel orientation to achieve flowrates greater than the maximum flowrate available. For example our 6″ MVP can limit flow to 469 gpm. For applications that require flows greater than this, many customers have successfully connected two of these valves in parallel with a common manifold. The controls contractor will need to set up the valves to use one common control signal.
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Advantages of the Next Generation Stem
Have you ever wished you could repair a leaking valve in the field without having to remove the valve from the system? Have you ever had problems with chemical treatments in HVAC systems destroying valve components? Have you had issues with hotter soldering practices mandated by legislation that eliminates the use of lead-based or other soft soldering materials damaging the stem o-ring and packing materials? If so, then Griswold Controls’ Next Generation products are the answer you have been looking for.
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Griswold Controls Solves Cold Shower Issues
Cold showers and lack of hot water are a building manager’s nightmares! Unbalanced systems also happen in domestic hot water recirc. and lead to loud complaints from tenants. Since 1960 Griswold Controls has made automatic flow limiting (automatic balancing valves) for the HVAC industry. An automatic flow limiting valve maintains a constant flow in spite of pressure changes in the system, so the equipment in each zone has the flow it needs at all times. In comparison, when a system is unbalanced you have some equipment in the building that has excessive flows due to high-pressure differentials and some equipment that has inadequate flows due to lower pressure differentials. High flows can lead to excessive heating/cooling, high-velocity noise and erosion, wasted pump energy, and dehumidification problems. Low flows can lead to inadequate heating/cooling and short-circuiting of equipment. Typically an unbalanced system has the higher flows near the pumps and the lower flows are in the index circuit, the equipment farthest from the pump.
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LEED Points Using Valves to Improve Efficiency of HVAC System
Griswold Controls has been a proud member of US Green Building Council (USGBC) for almost ten years. Although USGBC does not certify, promote, or endorse products and services of individual companies or manufacturers, they do recognize that products and services play a role in energy management and therefore products can help projects with credit achievement. Using Pressure Independent (PI) Valves can help achieve energy savings in the HVAC system. Because of the energy savings, a LEED specialist can apply for credit points in the following categories and use our valves in the application.
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Using Automatic Valves to Determine System Pump Requirements
Automatic Valves can be used to determine System Pump Requirements. The pumps in most chilled water systems are over-sized for the head pressure. Trimming the pump(s) to match the requirements of the system can provide significant energy savings, but there are two prerequisites – the system must be balanced, and the amount of excess pump head pressure has to be determined. Griswold Controls automatic flow limiting valves make it a breeze to meet these demands. First, the system is automatically balanced.
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Protect Your Cooling Towers with Hi-Flow Cartridges
Griswold Controls’ Hi-Flow automatic balance cartridge was designed for the unique needs of a cooling tower and has been used for decades in the Wafer and Grooved End valves to control the flow rate of condenser water. Heated water from the condenser in chillers is piped to a cooling tower, usually on the roof. The heated condenser water is sprayed into a stream of cooler air and flows to the bottom through “fill” designed to expose the water to as much air as possible. The water is cooled while the warm air is blown away from the tower. The cooled water is then returned to the chiller. Controlling the flow rate of water into the cooling tower is critical to ensure there is no underflow or overflow to maximize the heat removal from the water.
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Heating and Cooling Schools and Universities for Decades
Maintaining optimal heating and cooling in an educational facility isn’t just about student and teacher comfort. While studies show that students learn better in comfortable temperatures, students of this generation care more about sustainable living than any prior generation and base many decisions, including their educational choices, on green living. Therefore, reducing your campus’ carbon footprint, while saving money on HVAC energy costs and maintaining student comfort, helps your campus’s HVAC System score an A+ for efficiency.
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Hotels – Ensuring Guest Comfort 24/7 using Griswold Controls Valves
Since 1960 Griswold Controls has made automatic flow limiting (automatic balancing) valves for the hydronic HVAC industry with valves installed in thousands of hotels worldwide. An automatic flow limiting valve Hotel Hydronic HVAC maintains a constant flow despite pressure changes in the system, so the heating or cooling coil in each zone has the flow it needs at all times. In comparison, when a system is unbalanced you have some equipment in the building that has excessive flows due to high pressure differentials and some equipment that has inadequate flows due to lower pressure differentials. High flows can lead to excessive heating/cooling, high velocity noise and erosion, wasted pump energy, and dehumidication problems.
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Healthcare Facility Experts with 3000+ Successful Hospital Projects as Proof
Griswold Controls valves have been installed in thousands of hospitals and healthcare facilities across the country. With our substantial experience, we know that Hospital HVAC Systems work harder than HVAC systems in most buildings because they run 24/7/365. Furthermore, they contribute to the health of the patients in the room by improving air quality and mitigating airborne disease transmission. Most hospitals have year-round cooling requirements due to medical devices or systems that generate tremendous amounts of heat such as imaging systems, bright lighting, and refrigeration. Unlike most HVAC systems where comfort is the primary objective for design, engineers designing hospital HVAC systems have additional details to consider that impact health and safety. Therefore it’s critical that these systems operate with consistent high performance in the most cost-efficient method possible.
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MVP® Helps to Protect Your Chiller in a Variable Primary Flow System
n Variable Speed Pumping systems the chiller must be protected from changes in flow rate because changing flow rates can cause pressure fluctuations in the refrigerant. This can lead to discharge of refrigerant and the resulting environmental damage to the space. Traditional installations use a modulating control valve at the chiller to try and maintain a constant flow, or at least a flow above the minimum allowable flow. Griswold Controls - MVP Valve The Griswold Controls’ MVP® not only maintains a constant flow regardless pressure changes – but it also has a position display on the actuator. That means you can tell what position the actuator is in at any time.
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Side Stream Filters
Side stream filters are installed on almost every commercial hydronic system, diverting a small portion of the total flow from the discharge of a circulating pump through the filter, and back to the pump inlet as shown here. The media in these filters is very fine and capable of removing small particles. As with any filter, it works best if the flow rate through it is controlled to a recommended maximum. If overflow occurs, the media can actually be ripped out of the casing and thrust into the system. A sight flow indicator is usually installed to show that flow exists, but not how much. In most cases, a designated person physically throttles the flow through the system using an isolation ball valve to whatever flow they think is correct.
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Using Griswold Controls Valves for Fluids Other Than Water
Griswold Controls Valves can control the flowrate in fluids other than water, including air. A simple equation can be used to convert the flowrate of various liquids if you know the Specifc Gravity of the liquid. (For a conversion for air please contact the factory.) Automatic Flow Limiting Valves To determine flowrate required for a Griswold Controls cartridge use the following formula: Q=Q1√SG Where Q=Flowrate of Cartridge Q1=Flowrate of Liquid Desired SG=Specific Gravity of Liquid
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Converting 3 – Point Floating Actuators to On/Off Actuators
With more and more actuator manufacturers removing on/off control actuators from their product line, the Controls Contractor is forced to find ways to convert the standard threepoint floating actuators (also called tristate) to on/off actuators (also called two position). Griswold Controls has worked with Siemens to offer a solution with their GDE131.1P actuator. Floating Actuators Form C, SPDT Relay The diagram on this page is the Siemens GDE131.1P wiring diagram. The contractor will need to add a SPDT relay to their wiring system which costs less than $5. This type of relay output is found on all building automation systems and allows a three-point floating actuator to work in place of an on/off actuator
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Air in HVAC Systems
Griswold Controls recommends venting the air from the HVAC system to protect equipment from damage and limit noise. Air trapped in a system can lead to nuisance vibrational noise due to the pulsing of springs or diaphragms. It can also lead to cavitation which shortens the life of HVAC product. ASHRAE Fundamentals Handbook 2009 edition supports the connection between air and noise in chapter 22, “water velocity noise is not caused by water, but by free air, sharp pressure drops, turbulence, or a combination of these, which in turn cause cavitation or flashing of water into steam” Therefore it is important to remove air in both Automatic Flow Limiting Valves as well as Pressure Independent Valves.
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Proper Valve Installation
Heat pump applications require a quick opening actuated control valve to protect the compressor from failure – most manufacturers recommend that the control valve deliver adequate chilled water to the compressor within 30 seconds or less to prevent overheating. Griswold Controls has a few options for this application. The Balance Zone is a compact combination flow limiting and actuated valve. Its compact size makes it a competitive option for a heat pump control valve. For this application use the Balance Zone with the on/off EV.1.4 actuator. This actuator has a built-in end switch that can be wired so that when it is triggered, the compressor is powered on. When the switch is triggered the valve is about half way open and the flow will be sufficient to protect the compressor from failure.
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Measuring Flow – Venturis Are the Best!
When a Contractor’s Manual Balance Valve readings are anything less than ±1% accurate, the engineer’s system design is costing someone money. In many installations, contractors may sacrifice accuracy for space considerations since traditional Manual Balance Valves require straight pipe length upstream and downstream. Straight pipe length is not required with Griswold’s Disturbed Flow Measurement used exclusively in the QuickSet Manual Balance Valves. When the engineer specifies a QuickSet, they can count on the balancing contractor getting a ±1% test accuracy no matter what space the contractor has to install the valve. The engineer’s QuickSet specification guarantees the energy efficiency and lower operating cost desired by the owner.
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Benefit of Using Flow Limiting Valves with Modulating Temperature Control Valves
Many statements have been made about the unsuitability of automatic flow control valves (more accurately called flow limiters) for use in tandem with modulating temperature control valves (TCV). This article will address the issue and show that these claims are not true. In order to do a comprehensive analysis we will look at the following: What automatic flow limiting valves do The output vs. flow of the load(s) when control is provided by modulating the flow. A comparison between manual balance and automatic flow limiting
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Proper Valve Installation
Since 1960 Griswold Controls has made automatic flow limiting (automatic balancing) valves for the hydronic HVAC industry. They have valves installed in casinos all over the world. An automatic flow limiting valve maintains a constant flow in spite of pressure changes in the system, so the heating or cooling coil in each zone has the flow it needs at all times. In comparison, when a system is unbalanced you have some equipment in the building that has excessive flows due to high-pressure differentials; and some equipment that has inadequate flows due to lower pressure differentials. High flows can lead to excessive heating/cooling, high-velocity noise and erosion, wasted pump energy, and dehumidification problems.
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Fail-safe – Capacitor Return vs. Spring Return
A fail-safe actuator returns to a pre-set home position when power is removed from the actuator. In comparison a non fail-safe actuator stays in its last position when power is removed. Fail-safe actuators are often used on crucial valve applications that require protection from excessive temperatures, such as preventing coils from freezing or rooms from overheating. If the fail-safe actuator is set to fail closed then when power is removed the actuator will rotate to the closed position. If an actuator is set to fail open then when power is removed the actuator will rotate to the open position. A standard rule of thumb is heating valves are usually fail-safe “normally open” to prevent the coil from freezing. Coiling valves are normally not fail-safe but if the engineer specifies fail-safe then they are typically “normally closed.” It is important to verify with the contractor or engineer their preference.
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Converting Actuator Requiring 2-10vdc to Accept 4-20mA Signal
One of the differences among building control systems and electronic products like actuators is the type of control signals that are acceptable. For example some systems can read voltage while other systems can handle voltage or current. When talking to Controls Contractors you may hear them ask for a modulating actuator with 2-10vdc signal (voltage) or 4-20mA signal (current) because they want to match their electronic product to the building’s control system.
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