A summer air-conditioning shown below is required to maintain a certain room at specified conditions. The layout of the system is indicated on the next page and the specifications are listed below. System specifications: Required room temperature: 23⁰C, 50% Relative humidity Atmospheric pressure: 101 kPa Outside air conditions: 30⁰C, 80% Relative humidity Sensible heat gain: 5 kW Latent heat gain: 4 kW Temperature rise across fan: 1.5⁰C Temperature of air leaving cooler: 12⁰C Temperature of air entering room: 18⁰C Apparatus dew point of cooler: 7⁰C

A summer air-conditioning shown below is required to maintain a certain room at specified conditions. The layout of the system is indicated on the next page and the specifications are listed below. System specifications: Required room temperature: 23⁰C, 50% Relative humidity Atmospheric pressure: 101 kPa Outside air conditions: 30⁰C, 80% Relative humidity Sensible heat gain: 5 kW Latent heat gain: 4 kW Temperature rise across fan: 1.5⁰C Temperature of air leaving cooler: 12⁰C Temperature of air entering room: 18⁰C Apparatus dew point of cooler: 7⁰C

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter50: Commercial, Packaged Rooftop, Variable Refrigerant Flow, And Variable Air Volume Systems

Section: Chapter Questions

Problem 18RQ: Explain how carbon dioxide levels can be used to estimate the occupancy level in a particular area...

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A summer air-conditioning shown below is required to maintain a certain room at specified conditions. The layout of the system is indicated on the next page and the specifications are listed below.System specifications:Required room temperature: 23⁰C, 50% Relative humidityAtmospheric pressure: 101 kPaOutside air conditions: 30⁰C, 80% Relative humiditySensible heat gain: 5 kWLatent heat gain: 4 kWTemperature rise across fan: 1.5⁰CTemperature of air leaving cooler: 12⁰CTemperature of air entering room: 18⁰CApparatus dew point of cooler: 7⁰C Draw the processes on a psychrometric chart and determine the following: 1.The ratio of mass flow rate of re-circulated air to the mass flow rate of air supplied to the room. 2.The heat removed by the cooling coil.3.The heat supplied in the re-heating coil. 4.The cooling coil bypass factor.
On a cold winter day, you turn up the thermostat in your house. Assume that your house is well sealed and that no air enters or leaves the house. When the air temperature in your house rises a short while later, what statement is correct regarding the air pressure? Question 10 options: The air pressure does not change at the higher temperature. The air pressure increases at first but then decreases again as the temperature approaches its higher value. The air pressure is lower at the higher temperature. The air pressure decreases at first but then increases again as the temperature approaches its lower value. The air pressure is higher at the higher temperature.
T₁ = 10°C $₁ = 30% V₁ = 45 m³/min 10°C Heating coils Air T₂ = 22°C 2 Celllllll3= 25°C = 60% $1 = 30% Humidifier 22°C %09 = 50 AN EXAMPLE The amount of heat and mass at each point along with the properties of the air? 25°C I need a clear answer by hand, not by keyboard and fast answer within 20 minutes. Thank you | dybala 17
Newton's Law of cooling states that the rate at which heat is lost by a heated body is proportional to the difference in temperature between the body and the surrounding medium. Match the following statements/phrases with the corresponding item in the drop down box. Choices in the box 1. In accordance with the stated law obove, we have the equation? 2. If a thermometer is taken outdoors where the temperoture is 5 deg C, from a room in which the temperature is 20 deg C and the reading drops 10 deg C in one minute, the working equation is? 3. In the obove problem, separoting the variables and integrating will result to? 4. In the obove problem, how long, in minutes, after its removal from the room will the reading be 6 deg C? 5. In the obove problem, ofter 30 seconds, whot will be the thermometer reading? 5.2 dT(body temp)/dt = k(Temp of medium - 5) dr(body temp)/dt = k(Temp of body - Temp of medium) Temp of body = Cenkt +5 2.5 13.7 dr(body temp)/dt = k(Temp of medium - Temp of body)…
QUESTION 1 A 120-ton capacity chiller, based on a refrigeration cycle, is used to maintain a coolant temperature of 35 deg. F. The chiller exchanges heat to the surrounding air at 70 deg. F. This unit utilizes a 150 hp motor. What is the rate of heat removal from the coolant, in Btu/hr? O1,440,000 O 381,675 O 1,821,675 O 120 QUESTION 2 A powerplant operates between a furnace at 990 deg. Fand cooling water delivered from a nearby river at 70 deg. F. What is the maximum possible efficiency of this powerplant, in %? Oa. 72.8% Ob. 27.2% Oc 92.9% Od.63.4% QUESTION 3 If fuel oil is supplied to a power plant furnace at a rate of 60,000 gallons/hr, and the oil has a heating value of 150,000 Btu/gallon, and the plant has a thermal efficiency of 30%, what is the power output of this plant (in MW)? Oa. 2637.6 Ob.9000 Oc 2700 d. 791.3
true or false pleassse faster Saturated steam’s enthalpy EQUATES the vapor enthalpy of steam at that given temperature or pressure. Steam is the BASIC source of energy in the food industry The average latent heat of water at any temperature is EQUAL to difference of the vapor and liquid enthalpies at that temperature Under the wet-steam region, isothermal and isobaric lines moves in the SAME direction Degree superheat is the temperature DIFFERENCE of the superheated steam temperature from saturated steam temperature Water CAN boil in a temperature below 100C LIQUID ENTHALPY also refers to the energy of liquid water The enthalpy of steam plotted in steam chart or tabulated in steam table is reckoned from ABSOLUTE ZERO Steam is STABLE even up to 2000K The SUM of moisture and quality under wet-steam region is equal to 1
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VAPOR COMPRESSION REFRIGERATION SYSTEM ANALYSIS 3 Warm environment Он Condenser Expansion valve Evaporator QL Cold refrigerated space in Compressor 1 FIGURE 1: VAPOR COMPRESSION REFRIGERATION CYCLE The chiller system operates based on the vapour compression refrigeration cycle (figure 1) with a single stage compression. The isentropic efficiency of the compressor is assumed at 85%. The refrigerant exit evaporator and condenser can be assumed as saturated.
2. Conduction is function of the environment's humidity and the airflow/exchange next to the skin. True False 3. One of the amendments to Regulation 854 that came into force in 2016 is strengthening and improving requirements regarding high visibility safety apparel. True False 4. Cold stress is also known as "thermal strain". True False 5. Dynamic force presents a greater risk of strain than static force. True False 6. In underground climate, auto compression of air adds 4-60C/km to the wet bulb temperature. True False An industrial machinery gives out 112 dBA of noise 1 m away from the source, which requires double hearing protection. You are a worker performing work for 8-hrs around the machinery and you are required to wear double hearing protection. An earplug which has an NRR of 29 dB and an earmuff with an NRR of 31 dB. The suggested derrating percentage of the hearing protections are 60% and 55% of the NRR, respectively. Does the double hearing protection reduce the noise level…
Which of the following will be useful for modelling the process in an air conditioning unit O No-flow Energy Equation O Steady Flow Energy Equation O Fourier's Law O Newton's law of cooling
select if true or false for the following questions 1. For a standard condenser in a refrigeration system, the thermal energy (in J) is equal to the mass (in kg) multiplied by the change in enthalpy across the condenser (in J/kg). 2. Consider a basic refrigeration cycle: Since it requires less work to compress a liquid than a vapor, the entire refrigeration process would work better if the compressor was replaced with a pump. All else being equal, increasing the mass-flow rate of refrigerant will increase the rate of heat transfer at the system’s evaporator. All of these (except, of course, the one labeled, “None of these.”) None of these.
2 points The process, generally used in winter air-conditioning to warm and humidity the air, is called; * O heating and dehumidification humidification O heating and humidification O cooling and dehumidification