In today’s fast-paced digital era, the demand for cooling in data centers and server rooms is on the rise. Ensuring efficient and stable operation of equipment hinges on the careful selection of precision air conditioning units. However, the various types and technical specifications of precision air conditioners can make it a daunting task to clearly articulate your cooling requirements when inquiring for your quotations.
In this article, we will leverage years of experience in selecting and designing precision air conditioning solutions for clients. We aim to provide key aspects for selecting precision ac in critical environments from the customers‘ perspective to enhance your communication with manufacturers or other suppliers regarding your precision air conditioning needs. If you are unfamiliar with precision air conditioning products and are concerned about accurately describing your requirements, leading to unmet needs, we encourage you to continue reading to prepare for future discussions.
How Precision AC Works?
Before we start discussing how to select an appropriate PACs, it may be helpful to provide an overview of its basic principles. As illustrated in the following picture, the principle of a standard air-cooled precision air conditioning system can be described as follows:
- Compressor: The cycle begins with the compressor, which draws in low-pressure, gaseous refrigerant (approximately 12°C) and compresses it into high-pressure, high-temperature gas (approximately 80°C).
( How exactly does compression increase temperature? ) - Condenser: The high-pressure gas enters the condenser, where it releases heat through the cooling action of a fan and condenses into high-pressure, ambient-temperature liquid (approximately 35°C).
- Expansion Valve: The condensed liquid refrigerant then flows through the expansion valve. Inside the expansion valve, the refrigerant undergoes pressure reduction, resulting in a temperature drop, transforming it into low-pressure, low-temperature liquid (approximately 7°C).
- Evaporator: The low-temperature liquid refrigerant enters the evaporator, absorbing heat from the surrounding environment (such as the room), cau sing it to vaporize again into low-pressure gas, thereby achieving a cooling effect.
- Cycle: After evaporation, the gaseous refrigerant returns to the compressor (temperature returning to approximately 12°C), completing the cycle.
Figure Out Your Cooling Load Requirements
Once you have identified the cooling method for your precision air conditioning, it’s essential to provide specific cooling load requirements.
First, if you already have specific data on cooling load needs, you should communicate this directly to the manufacturer to ensure that the selected air conditioning unit has a cooling capacity equal to or greater than your requirements.
Second, if you do not have clear cooling load specifications, you can estimate them based on the total load of the server room. This involves calculations based on room size and equipment heat output, using the following formulas:
- Room Cooling Load Calculation:
Room Cooling Load = Room Area × 0.2 kW/m²
- Equipment Heat Output Calculation:
Equipment Heat Output = (Total Cabinet Equipment Load kW or UPS Capacity) × 0.8
- Alternative Cooling Load Calculation:
If load information is unavailable, the cooling load can also be calculated as:
Cooling Load = Room Area × (0.35 – 0.5) kW/m²
Understanding these calculation formulas isn’t mandatory; manufacturers will perform these calculations once they have enough information. After you get your needed cooling capacity, it’s time to select types and specifications of precision ac to match with your requirements.
Understand Cooling Methods of Precision AC
After you got your calculated cooling capcity for your IT space, it is time to figure out how to make it cool. There are four types of cooling methods used in precision cooling system of data centers, telecom or other critical environments. Each cooling technology is designed to adapt to specific environmental conditions.
- Free Cooling
This can be the most cost-efficient option among the four methods. The principle relies on utilizing the low-temperature ambient air or other natural cold sources. When the outdoor temperature is low enough, the system can directly introduce the cold outdoor air into the data center or use heat exchangers to transfer the heat from the data center to the cold outdoor medium, avoiding or reducing the operation of mechanical refrigeration equipment to save energy. If your operational environment is in a low-temperature area, such as locations at high latitudes or altitudes, a cooling system with free cooling can significantly lower the PUE of your data centers. - Air-Cooled
Suitable for small to medium-sized data centers, taking into account the location and installation space of the outdoor unit. It works by using fans to draw in outdoor air. The air passes through the evaporator coil where the refrigerant absorbs heat from the air. The heated refrigerant then goes to the outdoor condenser coil, where fans blow air over the coil to release the heat into the atmosphere. The cooled refrigerant cycles back to the evaporator to repeat the process. For some locations with stable natural cold source, choosing PACs with a combination of air-cooled and free cooling technology is a quite wise. - Water-Cooled
In a water-cooled system, the length of the refrigerant circulation piping is relatively short, which addresses the limitation of air-cooled air conditioners, where the refrigerant piping cannot be extended too long due to potential pressure loss and decreased efficiency. Here, water acts as a heat transfer medium. The refrigerant absorbs heat in the evaporator and becomes a high-pressure, high-temperature gas. It then flows to a water-cooled condenser, where water circulates around the condenser tubes. The water absorbs the heat from the refrigerant, cooling it back into a liquid. The heated water is then sent to a cooling tower, where it releases the heat into the air and is cooled down to be recirculated. Please note that water-cooled systems don’t need outdoor condensers but typically require cooling towers to dissipate heat effectively. - Chilled-Water
Chilled water PACs excel in large-scale operations by efficiently delivering consistent cooling over longer distances. A chiller unit cools water to a low temperature (the chilled water). This chilled water is pumped through a network of pipes to air handling units or cooling coils in the data center. Air in the data center passes over these coils, and the heat from the air is absorbed by the chilled water. The now-warmed water returns to the chiller to be cooled again, completing the cycle. This design allows for precise temperature control and seamlessly integrates with free cooling options, significantly enhancing overall energy efficiency in data centers.
During your discussions with manufacturers, they will help you identify the most suitable cooling method based on your geographical context. While these cooling methods can meet most cooling needs in critical environments, if you require higher efficiency and reliability, or if your equipment has high computing density or load, you might want to explore dual-source precision air conditioning или liquid cooling solutions for data centers.
Analyse Your Environmental Conditions
A careful analysis of your location to set up your cooling system has always been essential to minimize your costs, lower your Power Usage Effectiveness (PUE) in critical environments, and also prolong your equipment’s lifespan. Generally, what you should consider is all about humidity and temperature. Based on this, you should think about your geo location such as your latitude, atitude.
- Temperature
Your geo location is a key aspect which we often think about while confirming the types of your precision ac, for its implying whether your cooling syetem get a stable cold source from the nature. Then, we are able to make clear if the free cooling and air cooled pac can be used in your area, which means more cost-efficient solutions are optional. Your latitude and altitude are two key aspects here we need to focus on: - Latitude
Higher latitudes typically provide more stable lower temperatures, allowing data center stakeholders to take advantage of a consistent natural cold source, which can help lower energy costs.Generally speaking, when the latitude exceeds 30°, especially in northern countries or regions, the use of natural cooling systems becomes more economical and feasible. - Altitude
Similar to latitude, higher altitudes result in lower air temperatures. For every 1,000 meters of elevation gain, the temperature typically decreases by approximately 6.5°C. This cooling effect is particularly advantageous for data centers, as it also provides a stable and consistent source of cold air.
In Colorado, USA, where many data centers are located at elevations exceeding 2,500 meters, they utilize natural cooling techniques that greatly reduce energy consumption, achieving energy savings of 30-60% compared to traditional air conditioning systems. Such implementations demonstrate how leveraging altitude can lead to significant operational efficiencies in cooling strategies. - Humidity
As you may know, the evaporation of liquids absorbs heat from the surrounding environment. Based on this principle, water-cooled precision air conditioning systems are designed to complement free cooling and air-cooled precision cooling systems, particularly when the distance between outdoor and indoor units poses challenges.
However, not every location is suitable for selecting a water-cooled design. One key reason is that evaporation is significantly influenced by environmental humidity levels. High humidity can slow down or even halt the evaporation process, diminishing the effectiveness of water-cooled systems.
In regions with consistently high humidity, the cooling performance of water-cooled systems may be compromised, leading to increased energy consumption and reduced efficiency. Therefore, it’s essential to assess local humidity conditions when considering water-cooled precision cooling solutions. In contrast, in areas with lower humidity levels, water-cooled systems can operate more effectively, offering substantial energy savings and improved cooling efficiency.
( You might like: Humidity as a Hidden Barrier: Why It Complicates Choosing Water-Cooled Precision ACs )
Besides what we mentioned up there, there are some tips that we want to share with you:
- First, when the outdoor temperature exceeds 45°C, a larger outdoor unit is required—specifically, one with greater cooling capacity than the standard-sized outdoor unit matched to the indoor unit under normal temperature conditions (typically 25–35°C).
- Second, if the outdoor temperature surpasses 50°C, high-temperature-resistant air conditioning systems should be selected, as conventional units may fail to operate efficiently or even shut down due to overheating.
- Last but not least, for special environments (e.g., coastal areas with high salt spray, oil fields, or regions with corrosive gases), anti-corrosion treatment for the outdoor unit is essential to prevent damage to its metal components and extend its service life. In oil and gas environments in particular, additional explosion-proof measures must be considered to comply with safety standards and avoid fire or explosion risks caused by flammable gases.
Understand Common Air Supply Methods
Different models of precision cooling systems may be designed with varying types of air supply. For instance, upflow from the air diffuser typically corresponds to air conditioners with lower cooling capacities, while larger room air conditioning systems tend to use either upflow or downflow designs. There are five methods for your reference:
- Upflow from the air diffuser: When the ceiling height is less than 300mm, the air supply distance should not exceed 8 meters.
- Upflow from the duct: Generally used for areas with lower heat loads and longer air supply distances.
- Downflow from below the floor: Suitable for situations where the floor height exceeds 300mm.
- Downflow from the underfloor fan: Suitable for floor heights exceeding 450mm, allowing for longer air supply distances.
- Horizontal airflow: Commonly used in enclosed hot and cold aisles as well as in micro-module environments.
The methods of air supply sometimes correspond to different requirements for cooling capacity. For small precision cooling systems like Soeteck 7.5-27.5kW Room Precision AC, an air diffuser is generally designed and installed into the body of the PAC, which means you cannot choose to remove it from your final quotation list. However, for larger scale room cooling precision AC, the air supply methods are optional. Clearly specifying your cooling requirements will help your suppliers design a better solution for you.
Clarify Your Installation Conditions
There are several aspects of precision ac installation conditions influencing your cooling solutions. Generally, the distance between indoor and outdoor units, and the space of you pac installation site. Basing on our experience and knowledge, we share some potential reasons why you need to pay attention to them:
- The Distance Between Indoor And Outdoor Units
Distance between indoor and outdoor units is often a “tough guy” for some large project. Because too long distance will lead to low pressure in the refrigerant lines. This may result in inadequate cooling, reduced efficiency, and increased energy consumption, which means a higher PUE. In this case, free cooling system and air-cooled system are probably not options for you. However, for the water-cooled PACs and chilled-water PACs, it will never be a problem.
( You might like: What Are the Differences Between Water-Cooled and Chilled-Water Precison AC?) - Installation Space
The installation space is essential for selecting the appropriate precision cooling system. Air-cooled systems need sufficient outdoor ventilation space and proximity to indoor units to maintain efficiency. Natural cooling systems depend on proper fresh air pathways and must avoid contamination from heat sources; limited space can reduce their effectiveness. Water-cooled systems require outdoor space for cooling towers and piping, while chilled-water units need access to centralized cooling lines and adequate ceiling or floor clearance.
Confirm Your Power Supply Requirements
When selecting air conditioning units, you need to verify power requirements, including voltage type and frequency. Different industries and regions have distinct power standards, which can influence the design of precision air conditioning units. Here are some common power standards:
- Standard voltage: 380V, 60Hz/50Hz, 3-phase
- Southeast Asia (Филиппины): 480V, 50/60Hz or 230V, 50/60Hz
- Most South American countries (excluding Argentina and Chile): 208V, 60Hz
- США/Канада: 208V, 60Hz
For manufacturers, special power requirements may involve non-standard customization, so it’s essential to communicate this information during your discussions to ensure the successful operation of your equipment upon delivery.
Заключение
Effectively communicating your precision cooling requirements to manufacturers is crucial for ensuring optimal performance in your server room. Focus on providing clear cooling load calculations, specifying air discharge methods, and detailing installation conditions. By doing so, you will not only facilitate a better understanding of your needs but also enhance your collaboration with suppliers. Consider creating a checklist of essential requirements to streamline your discussions and remain open to future scalability in your cooling solutions. Engaging with experts can further enhance your ability to secure efficient and reliable cooling systems tailored to your operational demands.
Контактная информация SOETECK
We are a company dedicated to serving customers worldwide, offering a complete range of precision AC solutions. From product selection, production, and delivery to after-sales service, we have a comprehensive team for sales, technical support, research and development, and after-sales, ensuring that your needs are met and your equipment’s reliability is guaranteed. Whether for pre-sales consultation, video calls, or on-site inspections, we encourage you to reach out to us.
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