TECHNOLOGY
Equaphase’s high-performance PCMs bring chiller-less cooling and energy conservation to energy storage.
The Equaphase PCMs are carefully and thoroughly prepared using patent-pending PCM chemistry and technology. After mixing, the PCM is then filled into containers and hermetically sealed.
These “PCM bricks” are stacked inside a tank, with space for water to flow in between the PCM bricks. The tank can be placed above-grade or below grade, e.g., underneath a parking lot. Piping then connects the tank to the existing cooling tower piping. The result is a resilient PCM cool storage system able to be retrofitted into most commercial/industrial facilities.
Four Systems. Every Application.
Equaphase PCM cool storage systems can be sized as full-storage systems handling 100% of the cooling load, or as partial storage systems — integrated into new or existing chilled water and packaged DX systems.
Equaphase 9
- ✓ Works with any existing chilled water system
- ✓ No low-temperature refrigeration required
- ✓ Under 3-year payback in many utility territories
- ✓ 30+ years of field performance
- ✓ Ideal for hospitals, universities, large commercial
Equaphase 13
- ✓ Cooling tower charges PCM overnight — chiller-free in suitable climates for most of the year
- ✓ Under 2-year payback in high demand charge territories
- ✓ Ideal for coastal California, Southwest, Pacific NW
- ✓ Patent-pending hydrogel PCM formulation
Equaphase 16
- ✓ Compatible with data center liquid cooling loops in dry or moderate climates
- ✓ Night charging — chiller-less in suitable climates, up to 80% energy reduction
- ✓ Thermal inertia adds cooling redundancy during chiller trips
- ✓ Provides immediate compute capabilities by reducing demand
- ✓ Ideal for colocation and enterprise data centers
Equaphase DX
- ✓ Integrates via refrigerant-to-water HX — no chiller replacement
- ✓ Pre-charged 5,000-gal roto-molded tank ships on flatbed
- ✓ Installs 1–2 days — works with 10–100 ton DX units
- ✓ Mass-market economics — same demand rates, smaller scale
Pre-Cooler Design: Charging and Discharge Modes
The Equaphase 9 system integrates directly into your existing chilled water loop using a booster pump and storage tank. The same piping configuration supports both full storage and partial storage operation — the only difference is whether chillers run during the discharge period.
During off-peak hours, the chiller produces cold water at 40°F which flows through the booster pump into the storage tank, freezing the PCM modules inside. The building load continues to be served at normal conditions (40°F supply / 48°F return) throughout the charging period.
Booster Pump: Constant GPM
During on-peak hours, warm return water from the building (57°F) flows through the booster pump into the storage tank, where it is chilled to 43–49°F as it passes over the thawing PCM modules. Full storage: chillers off entirely. Partial storage: one chiller supplements storage at reduced load. Demand charges fall in both cases.
Booster Pump: Variable GPM based on storage loop temperature at TS-1
Equaphase 16 Brings Extraordinary Savings and Efficiencies to Data Centers.
Existing data center cooling systems, typically with chillers and cooling towers, are looking to increase cooling efficiencies, cooling redundancy, and reduce the facility’s PUE. With data centers using chilled water supply temperatures of 20°C – 25°C, Equaphase 16, melting and freezing at 14°C–16°C, has been developed to specifically meet the rigorous conditions of the data center cooling system, providing fastest paybacks under 2 years.
For most of the year, depending on climatic conditions, diurnal temperature swings and low nighttime wet bulb temperatures, the PCM modules are charged/frozen at night using water chilled only by the cooling tower, with the chillers turned off and in stand-by mode.
With nighttime charging with the cooling towers, the Equaphase PCM cool storage system provides an 80% reduction in electricity consumption and water savings as well, reducing the facility’s PUE and allowing for increased “compute” power fast, while avoiding interconnection queues.
Owners of Commercial Buildings with Packaged DX Units Can Now Slash Electricity Costs with Equaphase PCM Systems.
Equaphase brings all the benefits of advanced PCM technology to the world of 20 to 100 ton packaged DX units. A new refrigerant-to-water heat exchanger turns the condensing unit into a mini-chiller, with water circulating through a self-contained, vertical, above-grade insulated PCM tank.
During off-peak hours, the condensing unit with the heat exchanger chills the water. Then it circulates through the tank, freezing the PCM modules. During the daytime peak-demand hours, the condensing unit is turned off. Water circulates through the cool storage tank and is chilled as it passes over the melting PCM modules. The chilled water then circulates to the building air handler, providing cooled air to the building as before. The result is the elimination of the scorchingly high demand charges and keeping your electric bills low. Payback periods of two years or less are available in high demand charge areas.
Schematic representation. Single series chilled-water loop with circulating pump and bypass valves enabling charge and discharge modes.
equaphase Technologies
Eutectic PCM Cool
Storage System
A Eutectic PCM Cool Storage System is a thermal energy storage system that utilizes phase change materials (PCMs) to store and release thermal energy to cool a building.
Equaphase Technologies’ Eutectic PCM Cool Storage systems provide energy conservation, power availability, water conservation and load management to data centers and liquid-cooled facilities.
Achieve chiller-less cooling for most of the year by freezing Equaphase’s eutectic PCMs at night with cooling tower-supplied water. Displace chiller and cooling tower operation during the day while the PCMs melt and cool the facility’s chilled water supply.
The result: payback periods from under two years to four-plus years. No other storage system, be it an electric battery, ice storage, or any other type of storage system, can slash energy and water consumption and provide low paybacks like the Equaphase Eutectic PCM Cool Storage system.
Equaphase’s high-performance PCMs bring chiller-less cooling and energy conservation to energy storage.
Now, Equaphase Technologies has developed three alternative Eutectic PCMs:
PCM | Freezing/Melting Temperature Range |
Equaphase 16 | 14-16℃ |
Equaphase 13 | 11-13℃ |
Equaphase 9 | 7-9℃ |
The Equaphase PCMs are carefully and thoroughly prepared using patent-pending PCM chemistry and technology. After mixing, the PCM is then filled into containers and hermetically sealed.
These “PCM bricks” are stacked inside a tank, with space for water to flow in between the PCM bricks. The tank can be placed above-grade or below grade, e.g., underneath a parking lot. Piping then connects the tank to the existing cooling tower piping.
Equaphase 16 is particularly appropriate for liquid cooled data centers, as data centers use liquid temperatures in the range of 20-30 degrees C. See ASHRAE’s “Datacom Encyclopedia.”
How Does it work?
Chiller-less Cooling with Equaphase Eutectic PCM Cool Storage System
The Equaphase Eutectic PCM Cool Storage System leverages large diurnal temperature differences, along with evaporative cooling tower and water-side economizer technology, to provide the vast majority of a data center or facilities’ cooling loads without mechanical refrigeration or refrigerants, while adding redundancy and resiliency to the facility’s cooling system.
At night, the cooling towers operate, without the chillers, to provide chilled water to the storage tank, where it freezes the Equaphase PCMs and charges the storage tank. The cooling tower, operating alone to supply chilled water, uses about one-fifth the electricity as when the chiller is operated.
Then, during the day, when temperatures are 10 to 18℃ higher, the water is circulated through the storage tank, and the Equaphase PCMs melt and chill the water used to cool the facility through the normal use of the water-side economizer/heat exchanger.
The result: Cooling the data center or facility without the chillers, and saving up to 80% in electricity consumption and on-peak demand. Further, by keeping the cooling towers off during the day, reducing the cooling towers run time, and using the towers at nighttime, water savings (and water treatment costs) can be reduced by up to 25%.
Equaphase Eutectic PCM Cool Storage Systems
Features and Advantages
Beyond Load Management to Energy Conservation.
Equaphase Eutectic PCMs have a high latent heat of fusion, allowing them to store a large amount of energy in a relatively small volume.
Equaphase’s predecessor, a company called Transphase Systems, employed a eutectic PCM with a phase change range of 47-50°F for effective load management in chiller-based air conditioning systems.
Now, Equaphase has added PCMs 13 and 16°C. These higher-temperature PCMs allow for higher charging/freezing temperatures. In some hot/dry climates, the cooling towers will be able to charge the PCMs at night and achieve chiller-less cooling even when it reaches over 100 degrees F during the day!
Eliminates Up to 80% of Chiller Operation
Equaphase uses a cooling tower to freeze a PCM most of the time. For the large majority of the year, Equaphase PCMs require no compressor operation at all.
In contrast, ice storage systems require sub-32 degree charging temperatures.
Space and Energy Efficiency
Compared to a Equaphase tank, a chilled water storage tank, relying solely on the specific heat rise of water with no phase change, takes at least four times the space.
Unlike PCM based systems, chilled water storage requires a large delta T across the load and which may not be available with increased chilled water supply temperatures.
Additionally, a Equaphase system doesn’t rely on maintaining a stratified chilled water temperature gradient inside the tank like a chilled water storage tank does.
Uses A Building's Existing Cooling Towers and Air Conditioning Equipment.
One of the primary advantages of Transphase’s original 47-degree PCM (now an improved Fusion 47) was its ability to be fully retrofitted into an existing facility’s chiller-based air conditioning system.
Fusion Phase’s new PCMs maintain this advantage by utilizing a building’s existing conventional air conditioning equipment, including cooling towers, pumps, and air handlers.
Also, no HCFCs or other refrigerants are added or used in the Fusion Phase PCM Cool Storage system. And the tank’s chilled water can be used in the facility’s fire protection system as well. Most significant, Fusion PCMs provide an added layer of redundancy and protection to the facility’s cooling system.
System Energy Use Comparison
Ice Storage, Chilled Water Storage & Eutectic PCM Storage Systems
EPRl Cool Storage Monitoring Workshop Presentation Material, September 1989
The Electric Power Research Institution (EPRI) produced a Cool Storage Monitoring Workshop report. Using the chiller to charge all three storage mediums, the Eutectic PCM Cool Storage System, using the 48℉ eutectic PCM, displayed significantly lower energy consumption and higher energy efficiency than ice storage or chilled water cool storage system.
Now, with the cooling tower supplied chilled water freezing Equaphase’s new higher temperature eutectic PCMs, chiller energy consumption plummets from about 0.85 kwh/ton-hour (in 1989) to zero for the vast majority of the year!
For further information about Equaphase Technologies, contact us.