Data, Tables, Tools, Guides
The application compares different systems based on a geographical location. Pack Calculation Pro is designed to compare different system designs, control strategies and refrigerants for your refrigeration or heat pump project, by calculating yearly energy consumption, as well as Life Cycle Costing (LCC) and Total Equivalent Warming Impact (TEWI).
– Cycle analysis (process design) – comparison of one stage direct expansion cycle and one stage flooded cycle.
– System sizing – calculation of component sizes from general criteria.
– System simulation – calculating operating conditions in a system with known components.
Component calculations – calculation of – components efficiencies and outlet conditions.
– Evaluation of operation – evaluation of system efficiency.
– Process investigation – e.g. moist air calculations.
– Cycle analysis (process design)
– System sizing
– System simulation
– Component calculations
– Analysis of operating conditions
– Transient simulation (cooling of an object/room)
– Refrigerant calculations (property plots, thermodynamic & transport properties, comparison of refrigerants)
– Life cycle cost (LCC)
A variety of liquids could be considered for Data Center applications.
When liquids are employed within separate cooling loops that do not communicate thermally, the system is considered to be air cooling. The most obvious illustration covers the chilled-water CRACs that are usually deployed at the periphery of many of today’s data centers. At the other end of the scale, the use of heat pipes or pumped loops inside a computer, wherein the liquid remains inside a closed loop within the server, also qualifies as air-cooled electronics, provided the heat is removed from the internal closed loop via airflow through the electronic equipment chassis.
Good piping design results in a balance between the initial cost, pressure drop, and system reliability. The initial cost is impacted by the diameter and layout of the piping. The pressure drop in the piping must be minimized to avoid adversely affecting performance and capacity. Because almost all field-piped systems have compressor oil passing through the refrigeration circuit and back to the compressor, a minimum velocity must be maintained in the piping so that sufficient oil is returned to the compressor sump at full and part load conditions.
Several HVAC systems require field refrigeration piping to be designed and installed on-site. Examples include Condensing units, Direct expansion (DX) coil in air handlers, Remote evaporators with air-cooled chillers and Chiller with a remote air-cooled condensers. This Guide covers R-22, R-407C, R-410A, and R-134a used in commercial air conditioning systems.
A 4-pipe heating and cooling plant contains both central heating and cooling equipment and is capable of delivering heating water and chilled water to the building simultaneously through four pipes (one heating water supply, one heating water return, one chilled water supply, and one chilled water return). Heating and cooling equipment within the building that is connected to a 4-pipe system will have four pipe connections, unless the equipment provides either heating only or cooling only. In this case, the equipment would have only two pipe connections.
HVAC (Heating, Ventilation and Airconditioning) component start-up procedures describe how to start the operation of each component. They specify the methods to be used and the checks that are needed. Start-ups and related measurements are carried out by the contractor. Commissioning provider assists the contractor in the beginning of each start-up process and reviews that no systematic errors are made.
– What is Primary-Secondary Pumping?
– PRIMARY-SECONDARY BASICS.
– PRIMARY-SECONDARY RULES, DEFINITIONS.
WHEN TWO PIPING CIRCUITS ARE INTER-CONNECTED, FLOW IN ONE WILL CAUSE FLOW IN THE OTHER, T0 A DEGREE DEPENDING UPON THE PRESSURE DROP IN THE PIPING COMMON T0 BOTH.
Expansion tanks are a necessary part of all closed hydronic systems to control both minimum and maximum pressure throughout the system. A comprehensive review of tank types and sizing procedure for expansion tanks.
How does Boyle’s law relate to sizing expansion tanks in domestic hot water systems?
what size expansion tank is required?
The heating, ventilation, and air conditioning (HVAC) equations. In both U.S. and Metric units.
Pump sizing involves matching the flow and pressure rating of a pump with the flowrate and pressure required for the process. The mass flowrate of the system is established on the process flow diagram by the mass balance. Achieving this mass flowrate requires a pump that can generate a pressure high enough to overcome the hydraulic resistance of the system of pipes, valves, and so on that the liquid must travel through. This hydraulic resistance is known as the system head.
Although work is underway to develop alternative refrigerants and improve refrigerant management strategies, the phase-down of HFCs will impose constraints on vaporcompression equipment that will require trade-offs among cost, efficiency, and safety. These constraints could present market opportunities for alternative space-conditioning technologies. Alternative technologies based on their development status (some technologies are in very early stages of development), potential for energy savings, and other factors that may affect their ability to compete with vapor-compression systems.
There are many different designs of chilled beams on the market, which makes the selection and comparison between product types and manufacturers difficult. However, there are technical details that can be compared when making a chilled beam selection.
There are four main steps that should be taken into account when selecting chilled beams
There are a number of types of radiant chilled ceilings on the market. Ensuring good thermal conductivity between the cooling element and the other parts of the radiant chilled ceilings is important to ensure maximum performance. The cooling capacity of chilled ceilings is one of the major selection criteria.
The piping and radiator connections shown in this section are diagrammatic and illustrate the proper method of making piping connections in steam heating processes.
– Two pipe steam systems radiator connections
– Piping connections for unit heaters (steam)
– Two pipe– #steam trap installations
– Two Pipe Steam Systems Convector Connections
– Exposed #Pipe #Coils– Two Pipe Steam
– One pipe #steam systems radiator connections
– One pipe steam systems #convector connections
– One pipe steam systems convector connections
There are many types of steam traps each having its unique characteristics and system benefits. Deciding which type of trap to use is sometimes confusing and, in many cases, more than one type can be used. The following is intended to point out system conditions that may be encountered and the characteristics of each type of trap.
Steam Trap – Operation, Advantages, Disadvantages And Primary Applications
Hydropneumatic tanks are primarily used in a domestic water system for draw down purposes when the pressure booster system is off on no-flow shutdown (NFSD). The NFSD circuitry turns the lead pump off when there is no demand on the system. While the system is off in this condition, the hydropneumatic tank will satisfy small demands on the system. Without the tank, the booster would restart upon the slightest call for flow such as a single toilet being flushed or even a minute leak in the piping system.
Hydropneumatic tank sizing is dependent on two factors:
– Length of time you wish the pumps to remain off in a no-flow situation.
– The tank location in relation to the pressure booster.
VRF systems are available either as heat pump systems or as heat recovery systems for those applications where simultaneous heating and cooling is required. In addition to providing superior comfort, VRF systems offer design flexibility, energy savings, and cost effective installation.
A VRF system offers flexible installation and energy-saving cooling and heating comfort and should be considered as an alternative to traditional systems for those applications where zoning or part load operation is required.
The interrelationships among human beings, ambient conditions, and conditions within the built environment. Metabolic Rates For Typical Tasks
VRF systems utilize refrigerant as the working fluid and can provide cooling only to multiple indoor fan-coil units connected to a single condensing unit, either cooling or heating to multiple indoor fan-coil units connected to a single heat pump unit, or both cooling and heating simultaneously to multiple indoor fan-coil units connected to a single heat recovery unit.
Thermal energy may be stored in three main ways:
– Sensible Storage
– Latent Storage
– Thermo-Chemical Storage.
In addition, the two common thermal storage strategies employed are:
– Load Levelling Strategy
– Load Shifting Strategy
The process by which fresh air is introduced and contaminated air is removed from an occupied space is termed ventilation. Ventilation is necessary to provide a continuous supply of oxygen. Air changes per hour (ACH) is a measure of the air volume added to or removed from a space in one hour, divided by the volume of the space.
The air volume for an HVAC system is calculated from the sensible heat in the conditioned space. For the typical heating and cooling unit, the calculation is for cooling because more air is needed to cool a space than to heat it. If the conditioned space can be properly cooled with a given amount of cfm, then the space can be heated correctly with the same amount of cfm.
For heating or chilled water systems serving air conditioning plant, the requirement for maximum heating or cooling occurs only at start up, or on infrequent peak design days. For the majority of the time, a reduced heating or cooling output will suffice. During these periods there is potential to pump less water, thereby reducing the annual pump energy consumption.
A data center design encompasses architectural (rack layout), structural, mechanical, electrical, fire protection, and cabling system. Sustainable design is essential because a data center can consume 40–100 times more electricity compared to a similar‐size office space.
The role of convection and conduction heat transfer in the performance of solar systems is obvious. Radiation heat transfer plays a role in bringing energy to the earth, but not so obvious is the significant role radiation heat transfer plays in the operation of solar collectors.
Hot Water Boiler Controls, Zone Controls, Three-Way Valve Controls, Room Thermostat Controls, Room Thermostat Controlling Pumps, Indoor/Outdoor Control of Boiler, Zone Control by Circulator Control, Three-way Valve, Control through Indoor/Outdoor Stat, Control through Return Water, Indoor/Outdoor Controls
The life-cycle cost analysis method is the most commonly accepted method to assess the economic benefits of energy conservation projects over their lifetime. Typically, the method is used to evaluate at least two alternatives of a given project (for instance, evaluate two alternatives for the installation of a new HVAC system: a VAV system or a heat pump system to condition the building). Only one alternative will be selected for implementation based on the economic analysis.
This guide focuses on systems that use Refrigerant-22 (R-22). While the general requirements are the same for systems that use other refrigerants, velocities and pressure drops will differ.