So, the new dynamic pressure is: Pd = 0.5v2. The target pH for the water is generally considered between 8.5 and 9.0 and may be obtained by adding small amounts of . This is very important for closed loop systems that may be exposed to freezing conditions. Figure 2. It is added to closed-loop water systems for freeze protection and/or burst protection - similar to the idea of adding anti-freeze to your car engine. The key concepts are: 1. The Standard Geothermal uses a mix of water, antifreeze (Propylene Glycol), and refrigerant. Pure water freezes at 32 F, but a 60% solution of ethylene glycol pushes the freeze point down to -60 F. While the freeze point of pure glycol is only -39 F, the synergy between glycol and water results in a much lower freezing point. Failure to make adjustments to a chillers refrigeration and control system for glycol operation can cause the following operational issues: 1. It is a distributed or decentralized system of water-to-air heat pumps located to serve each zone. I always figure for about 10% more glycol; as the glycol level lowers in the pump bucket you will have to switch the drain water hose to the pump bucket and some mixing will occur. The automated system operates as needed to add water or water-glycol solution to a closed loop heating, chilled water, process, snowmelt or radiant heat system. However, the potential for reduced maintenance costs could also justify this conversion in some situations. Hercules Cryo-Tek 1 Gal. Glycol is also thicker and more viscous than water, making it more difficult to push through the pipes. Although there is a chance that R-410A refrigerant . Closed Loop Temperature Systems below 45F, typically are resistant to bacteria growth, while systems above 45 F are more prone to bacteria development. The diaphragm only begins to compress when the water temperature rises. Expansion and Purge Kit You will notice that there are three valves on the Expansion and Purge Kittwo boiler valves and a ball valve. A properly designed, commissioned [more] In a closed system, the primary and secondary pumps are purely there to maintain flow by overcoming the frictional pressure losses of the system. 1.2 RELATED SECTIONS Propylene glycol has inferior heat transfer efficiency compared to ethylene glycol. For example, a 20% ethylene glycol solution results in a 6% loss of heat transfer, whereas 40% glycol solution results in a 14.5% loss of heat transfer. Any fluid with a pH below 7.0 should be replaced. Another way, is thru leaky system gages, and or pipe sensors and probes.I understand your system is new, so don't take a chance, and install the 15$ automatic air . END OF DATA SHEETS 1. Takes Up Less Space No one has unlimited space within their facility. By adding ethylene glycol to the water to create a 60% solution, the freezing point plummets to minus 60 degrees Fahrenheit. As you understand, you should have a make-up water pump and an expansion tank (tank maintains stability in the pressure as the pump cycles on/off). Glycol-water mixtures are commonly used in facilities to provide freeze protection in HVAC closed loop heating and cooling systems. This is very important for closed-loop systems that may be exposed to freezing conditions. If you use a pump to remove the water (will still need to vent) then merely swap the hose connections on the pump to add the glycol. The precautions taken on laying up (either wet or dry) will add years to chiller life and prevent shutdowns Wet layup: biocide/biodispersant/2-3x normal inhibitor residual Air can enter a closed loop system in a few different ways. You might get a little air in the system but if only a little the air removal device should handle it. First, you should always install a water meter on the makeup water line to the closed loop system. The glycol must be maintained at the appropriate level, usually 25 to 30 percent of the fluid, to provide adequate protection from corrosion and freezing. We know that the total pressure in a closed loop chilled water system is static pressure plus dynamic pressure, the higher the water velocity, the greater the dynamic pressure. In theory, closed loops typically expect a 5 to 7% annual water loss. Compare this to 50 per cent glycol at 0.84 Btu/ (lb*oF) and you can see that glycol has 16 per cent less heat carrying capacity. It is good practice to maintain a slightly positive pressure in a closed-loop cooling system to: Prevent air being drawn into the system at vent locations close to the chiller, which is caused by the pump creating a vacuum in the return line. reinstalled antifreeze to hydronic heating boiler.so it will not freeze in cold weather In systems that contain aluminum heat exchangers, a special pH sensitive mix is required. Which is better for a closed loop system and why? Let's look at some of the pros and . The glycol is then pushed through a closed circuit of tubing or piping that is connected to the glycol chiller. For systems with the fill point located . Remember Craiglisting 50 miles down that dirt road to buy 55 gallons of green mystery fluid off those rednecks?This is a wonderful guide to how to put glycol. It creates a large surge and sometimes dislodges stuck air pockets. Pressurizing the air side of the tank to equal the static pressure of the water at the expansion tank location and before adding water to the system. This system comprises one or more chillers, cooling tower(s), condenser-water pumps, chilled- Pure ethanol (the type of alcohol that people drink) is . A closed-loop, solar water heating system. Low pressure (Lo1) safety trips 3. A closed system circulates the same fluid around and around, and is completely separate from the domestic water supply. Also run the system pump to make sure no bubbles are hiding in the impeller. Optimize pump performance by providing a net positive suction head to. The specific heat also changes with temperature and it only gets worse for glycol at lower temperatures. This prevents cold water from partially compressing the air in the tank. Special glycol feeders must be used to add . As Mike writes, heat (and I'd add, time) screws up the Ph. Examples of systems requiring freeze proofing include systems in which pipes are exposed to cold air and ice and snow melting systems. Pure water freezes at 32 F, but a 60% solution of ethylene glycol pushes the freezing point down to -60 F. While the freezing point of pure glycol is only -39 F, the synergy between glycol and water results in a much lower freezing point. Get A Free Survey Water-based HVAC systems that are exposed to freezing temperatures may be damaged due to the formation of ice, which causes coil tubes to swell, rupture or burst. 2. A chiller is a type of refrigeration system that cools a tub of glycol to reduce its temperature. The automotive antifreeze tester shows current mix is about -20C 5. Connect up, purge the air by cracking open/ shut the ball valve, pushing all the air back into the dustbin. what i personally use on my geo closed loops is a solution called "environol" it is non toxic, and safe for the enviroment, epa certified! There are two major types of antifreeze used. Our glycol feeders maintain a consistent pressure in closed loop systems automatically feeding based on a pressure drop. basically environol is 99% pure grain alcohol, with a blue dye added to it. How Glycol Alone Prevents Freezing in a Closed Loop System In a closed loop system, the water could freeze if exposed to temperatures below 32 degrees Fahrenheit. event. Glycol concentrations can run from 20% to 50%, with the actual glycol concentration There is also a non toxic glycol used under the brand name environol. Ethylene Glycol Low glycol levels can allow microbiological growth and corrosion that can quickly cause damage to the system. The water/glycol solution must be regularly sampled and tested to . In addition, Glycol is also regularly used to allow low temperature operation in thermal energy storage systems, where ice is made at night and used the following day to cool the building. While glycol protects the loops from freezing, it does reduce the efficiency of the fluid. The chilled water system must be flushed, cleaned and sanitised prior to adding a new water/glycol solution. There are three principle types of closed-loop cooling systems to consider: air-cooled or dry (no water is consumed), evaporative (heat is rejected using the process of evaporation, water is consumed) and liquid-to-liquid. 1.1 INTENT.1 This Section specifies services and material required for onsite, cleaning and chemical treatment of a multi metal, closed loop [glycol heating system] glycol water system]. While, the Waterless Geothermal System uses R-410A refrigerant. Industrial Glycol Application In Closed-Loop Water Systems Industrial glycol is composed of either ethylene or propylene glycol, a corrosion inhibitor, and water. It is the industrial equivalent of an . Post back if you have further questions. In most cases, the primary reason for converting a closed loop hot water heating or chilled water system to a glycol system is to prevent freeze/burst damage of equipment that is exposed to sub-freezing ambient temperatures. Run the charge pump for a long time in excess glycol and make sure the fluid in your bucket has NO bubbles. Upvote # 7 Not bother adding more glycol for now since I expect the make up volume will be small. Digitally displays the actual pressure of the loop and has a user settable control point for pump activation and pressure relief. The closed loop is always full of fluid, so the pump pressure requirements are much easier than those for a drainback system (you don't need to worry about head pressures). In general, about half of closed circuit cooler applications use water and about half use glycol. Propylene glycol is often used where toxicity is a concern. Components The above graphic depicts five "loops" commonly used in a chilled-water system to remove heat from zone or process loads. The glycol must be maintained at the appropriate level, usually 25 to 30 percent of the fluid, to provide adequate protection from corrosion and freezing. Ethanol is another antifreeze that has been used for geothermal earth loops. Let's say we double the water velocity. HVAC Chiller/Closed System Lay-up Cleanliness of the heat transfer surfaces Proper water treatment is essential for maintaining top efficiency minimizing corrosion. "Using narrow range pH paper is an easy and reliable way to read your pH level," said Hogle. According to Go Glycol Pros, glycol pH level should range between 8.0 and 10.0 to minimize corrosion and glycol degradation. Antifreeze, with a triple protection inhibitor system, helps protect against mineral deposits and sedimentation in hydronic heating and closed loop systems, solar heating systems, radiant heat and general plumbing systems. 3 ) Locate the shut off valve between drain valves and close the shut off valve. "A pH tester can also measure alkalinity or acidity of the fluid. Use a pipe volume chart to estimated system volume Add one pound of Table Salt (Sodium Chloride) per 1000 gallons of . Uses Less Energy Less pumps mean less equipment to power. Pour the glycol into the pump bucket, pump in while return water is captured in the empty bucket. Glycol has a freezing point of minus 39 degrees Fahrenheit. 6 ) Fill bucket at least half full of heat transfer fluid HTF (water or polypropylene glycol/water mix). 5 ) Attach washing machine hose to closed loop exit and place free end in the bucket. It has similar characteristics to methanol as an antifreeze: it flows well, has good heat transfer, and good freeze protection at 15F. As a result, glycol is often added to water to prevent freezing in systems that use Deciding which type of glycol to use in your HVAC system depends on several things, including local regulations. Each heat pump is served by a common building piping loop. Formula: G = V* (%D-%P) / 100- %P Known System Volume (in Gallons) Desired Glycol Concentration (in percentdetermined by chart in Nu-Calgon literature) Present Glycol Concentration in Circuit (in percentdetermined by refractometer) Result (in Gallons) Approximate amount (gallons) of Freez-Kontr'l 95/5 or Freez-Therm to add to circuit. Closed loop geothermal systems typically circulate a mixture of water and a small amount of antifreeze to lower the solution's freezing point. Biological Concerns The reactions that affect nitrite are controlled by varying forms of bacteria. Also, take extra care to avoid leaks in glycol systems. . .2 Chemically treat the system/boiler with old or fresh glycol specified in 2.2 and 3.5. The first boiler valve is located to the left of the expansion tank. Shut off the return hose to jack up the pressure and quick open it. The other end goes straight into a large dustbin which the glycol can be premixed into. In general, maintain no less than 500 ppm of sodium nitrite (preferably 1000 ppm), keeping levels of at least 350 ppm above the total concentration of chloride and sublet present in the closed loop system. Chilled-water systems can be efficient by design, with easy to understand controls. The feeder is constructed on a rugged 3mil powdercoated steel frame with a . Most facilities use ethylene glycol as this provides the most efficient heat transfer. The purge valve can be closed and the remaining glycol mixture in the bucket continues to be pumped into the solar closed-loop. yes u can drink it and not die, heh. Great! So the system temperature needs to be considered when selecting your chemical. HVAC freeze protection is typically provided by adding either ethylene or propylene glycols. Dandelion Geothermal uses a mixture of water and propylene glycol, a food-grade, non-toxic antifreeze commonly used as an additive in drink mixes . These microbubbles are very difficult to remove due to their low velocities in the system. Then, after a few minutes, only clear glycol returns into the bucket, proving that the solar loop is now full of liquid. Many owners simply open the valves to the air cooled chiller and allow the system and the makeup water to fill the pipe. Top off pressure with hose and nearby water supply. This causes a large amount of air to be introduced into the system. Glycol solutions are rarely used for closed loop systems in warmer climates, such as Florida or Arizona, unless they are being used as corrosion inhibitors. Have more HTF ready to add to bucket. Start the pump open the valve and monitor the system pressure adding more glycol mix to the dustbin as necessary until the desired charge is achieved. If we don't removing these dissolved gases, many problems can arise. General. One is during water treatment maintenance, another is during repairs or change outs of pumps, check valves, strainers, etc. Glycol based and methanol based. It is generally accepted that if a minimum pressure of 4-5 psig is maintained at the top of a closed hydronic system, all of the above requirements will be met with the possible exception of cavitation in hot water control valves. The second problem occurs when the cooling system is started. Rough Rule-Of-Thumb Estimate - Rated Tonnage of System X 10 gallons = Volume B. Water in a hydronic heating system should be free of air bubbles and dissolved gases, such as oxygen and nitrogen. Glycol can be fatal to felines and they seem to have a particular liking to the stuff. The amount of antifreeze needed to operate any given . Turn off the boiler, detach the hose, turn on gas, restart (6. This non-flammable, odorless liquid is also non-toxic. 4 ) Locate closed loop pressure gauge. Poor cooling output 2. Ethanol is also very flammable and can cause explosions and asphyxiation. The building piping loop serves as a heat source (heating mode) or sink (cooling mode) for each heat pump and is connected to the ground loop in a primary-secondary piping arrangement. Adding glycol to cooling systems will allow the use in both summer and winter. There are two basic types of glycol protection available for your closed-loop HVAC system: "burst protection" and "freeze protection." Burst protection is sufficient if the system will remain dormant or inactive when the temperature drops below freezing and there is adequate space to accommodate the expansion of an ice/slush mixture. If more air is introduced then you might have to do more. This is very important for closed-loop systems that may be exposed to freezing conditions. Special glycol feeders must be used to add fluid to the system when needed. Dissolved gases in a hydronic systems come together to form microbubbles. Let me run this past the Health Department. The reason that ethylene or propylene glycol is added to a closed system is to freeze-proof the system. Save on costs by reusing your water and coolant in a closed-loop system. Good air removal is crucial to the proper operation of any closed system. The coolant used in a closed-loop chiller can include: Water and water-based coolants (de-ionized water, water/glycol mix, water-based synthetic coolants) The flat-plate collectors can be mounted in almost any configuration, at great distances from the exchanger. This pushes liquid from the bucket into the expansion tank. Dandelion's mixture is just 22% propylene glycol. Just monitor the Ph of the glycol, especially after a heat induced pump failure or other high temp. The first step in setting up a glycol cooling system is to establish a glycol chiller in a closed loop system. There may be multiple closed-loop cooling systems at your power plant. A. Chiller and system hygiene and fluid maintenance. If your closed loop water system is losing and making up more water to 7%, you may consider exploring the source of the closed loop leak. Closed-loop chillers are recirculating systems that employ the use of coolant fluid in a closed-loop setup to exchange heat from various industrial and commercial processes. Closed loop water leaks are very common. Glycol Feed System for Chiller Condenser Water Loop | Antifreeze Protection - Percentage Water to Temperature Ratio Propylene Glycol% to Water 10% - 26F 20% - 18F 30% - 8F 40% - -7F 50% - -29F Additionally, it is important to use the right kind of antifreeze specifically for these systems. The Bell & Gossett Glycol Make-up Unit GF60 (GMU) is an automated 110V diaphragm pump with digital control. Closed-loop chillers have the benefit of only taking up a small amount of space due to the lack of coolant feed and waste lines. We recommend the use of pure water with a suitable (minimum 25%) inhibited Glycol mix to give the best system protection. A dry type cooling system uses an air-cooled heat exchanger or radiator. Low flow safety trips RESOLUTION Process high temperature (HTA)alarms 4. Pure water freezes at 32 F, but a 60% solution of DOWFROST propylene glycol pushes the freezing point down to -60 F. While the freezing point of pure glycol is only -39 F, the synergy between glycol and water results in a much lower freezing point. Thus, total pressure does increases with the pump head. antifreeze is used in the loop to protect it and your equipment from freezing if the loop temp dips below 32 degrees after leaving the unit. b u c k e t f il l e d w it h 5 0 /5 0 s o l u t io n o f p r o p y l e n e g l y c o l a n d w a t e r a c h e c k v a l v e o r g a t e v a l v e m u s t b e Pre-mixed with water and ready to use. . Measure the chloride concentration in the closed system and estimate the volume of the closed system; Estimate volume in a closed system. compared to the conventional closed loop water geothermal system that uses antifreeze, which can be very harmful to our ground water. There are at least few times you may need to add glycol to your chilled water system, but most commonly: during install topping off the tank after a fluid leak refilling the tank after a flush If you're confident the glycol you have is mixed as indicated by the label this is a pretty simple math problem. 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