Question

In: Mechanical Engineering

It is desired to air-condition a small one-room store located on the first floor of a...

It is desired to air-condition a small one-room store located on the first floor of a building several stories in height. The store is 20' wide and 40' deep, and the ceiling height is 12'.The front wall, which faces north, may be condidered as 100% glass. The partitions between this store and the stores on either side are 4" cinder tile, platered on both sides; and the rear wall, which contains 40 sq ft of glass, is of 4" brickbacked by 8" concrete blocks with furred metal lath and plaster on the inside surface. The floor construction consists of a 6" concrete slab with 1/8" asphalt tile flooring laid directly on the conconcrete. There is no ceiling in the basement. The store ceiling constructin consists of a 3" concrete slab with a suspended metal-lath and plaster ceiling below the supporting steel joist, and a double wood floor on sleepers above the slab. The store is to be kept at 80F and 50% relative humidity when the outside temperature is 95F and the relative humidity is 50%. The stores on either side are not airconditioned, nor are the offices on the floor above. The temperature in the basement may be assumed to be 7 1/2 deg warmer than the store. Assume that there will be an average of 20 persons in the store and that about 2,000 watts of fluorescent lighting will be used.

What are the coefficients of heat transmission for walls, ceiling, floor, and partitions?

Calculate the sensible heat gain of the store described . Do not include infiltration.

For the same store, find the number of pounds of fresh air needed per minute if 75% of the air is recirculated and 25% is fresh air.

Compute the number of tons of refrigeration required to air-condition the store.

Solutions

Expert Solution


Related Solutions

The admin office has one centralized copy machine located in a small room in the office....
The admin office has one centralized copy machine located in a small room in the office. Jobs arrive at this copy center according to a Poisson process at a mean rate of 2 per day. The processing time to perform each job has an exponential distribution with a mean of 1/4 day. Because the copy jobs are bulky, those not being worked on are currently being stored in a room some distance from the copy machine. However, to save time...
An air-conditioning plant is designed to maintain a room at a condition of 20oC dry bulb...
An air-conditioning plant is designed to maintain a room at a condition of 20oC dry bulb and specific humidity 0.0079 when the outside condition is 30oC dry bulb and 40% percentage saturation and the corresponding heat gains are 18000 W (sensible) and 3600 (latent). The supply air contains one-third outside air by mass and the supply temperature is to be 15oC dry bulb. The plant consists of a mixing chamber for fresh and recirculated air, an air washer with chilled...
1- Who is the inventor of air condition, and what year was the first modern air...
1- Who is the inventor of air condition, and what year was the first modern air conditioning produced? 2- Explain the the Combined Gas Law and 2nd law of thermodynamics briefly. 3- Explain the Air Conditioning Cycle in steps and use figure? 4- Describe the role of each part of the A/C system including: Compressor, Condenser ,Expansion valve and Evaporator. 5- What are the types of A/C? 6- Explain the working principle of Water Cooled Chiller and Air Cooled Chiller...
One way to store a lot of energy is to compress air in a large cave....
One way to store a lot of energy is to compress air in a large cave. The air starts at the corner marked by the black dot, where P = 1 atmosphere, V = 1 cave volume (let's choose 1,000,000 cubic meters), and T = 300 K. It is then adiabatically compressed to half the volume by a pump. As the air comes out of the pump it is hotter (how hot? what is the pressure?), but it cools to...
An entrepreneur opened a small hardware store in a street mall. During the first few weeks,...
An entrepreneur opened a small hardware store in a street mall. During the first few weeks, business was slow with the store averaging only one customer arrived every 20 minutes. Assume that the random arrival of customers is Poisson distributed. (a) What is the probability that exactly 5 customers arrive during one-hour period? (b) If the average revenue from each customer is MYR 12, what is the probability that the entrepreneur’s hourly earnings are at least MYR 24? (c) If...
An entrepreneur opened a small hardware store in a strip mall. During the first few weeks,...
An entrepreneur opened a small hardware store in a strip mall. During the first few weeks, business was slow, with the store averaging only one customer every 20 minutes in the morning. Assume that the random arrival of customers is Poisson distributed. (a) What is the probability that at least 1 hour would elapse between customers? (b) What is the probability that 10 to 30 minutes would elapse between customers? (c) What is the probability that less than 5 minutes...
The number of computers sold during one day by a small store is a random variable...
The number of computers sold during one day by a small store is a random variable XX with the following distribution: P(0)=0.12,P(1)=0.19,P(2)=0.19,P(3)=0.12,P(4)=0.06,P(5)=0.32P(0)=0.12,P(1)=0.19,P(2)=0.19,P(3)=0.12,P(4)=0.06,P(5)=0.32 a. Compute the expected value E(X)E(X). Give your answer two decimal places. E(X)=E(X)= b. Compute the standard deviation σ(X)σ(X). Give your answer two decimal places. σ(X)=σ(X)= 1 point) The problem below describes an experiment and defines a random variable. (a) Find the distribution of the random variable (and provide it as a chart). (b) Calculate the expected value...
a. A trendy French restaurant is one of the first businesses to open in a small...
a. A trendy French restaurant is one of the first businesses to open in a small corner of a commercial building still under construction. The restaurant has received rave reviews and has lines of diners waiting for tables most nights. i. In the short run (next few months), what measures should the restaurant take to maximize its profit? Explain. ii. In the long run (next six months and beyond), how can it maximize its profit? (Assume that the impressive state...
Saddleback Farms Inc. is a small agriculture-based company located on Nevis, one of the twin islands...
Saddleback Farms Inc. is a small agriculture-based company located on Nevis, one of the twin islands of the St. Kitts Nevis Federation. It utilizes ten (10) acres of land for growing coconuts, mangoes, avocados, various cash crops, and bushes for the manufacture of various teas for the local and regional markets. The owner/manager, Mr. Sylvester Livingstone and ten employees operate the farm. Mr. Livingstone believes that the pricing of products is flawed and engaged your firm to advise on any...
Pete's Market is a small local grocery store with only one checkout counter. Assume that shoppers...
Pete's Market is a small local grocery store with only one checkout counter. Assume that shoppers arrive at the checkout lane according to a Poisson probability distribution, with an arrival rate of 16 customers per hour. The checkout service times follow an exponential probability distribution, with a service rate of 20 customers per hour. The manager’s service goal is to limit the waiting time prior to beginning the checkout process to no more than five minutes. Also the manager of...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT