Maintain a cooler environment in non-conditioned buildings

Assignment Help Civil Engineering
Reference no: EM13858439

A roof-cooling system, which operates by maintaining a thin film of water on the roof surface, may be used to reduce air-conditioning costs or to maintain a cooler environment in non-conditioned buildings. To determine the effectiveness of such a system, consider a sheet metal roof for which the solar absorptivity as is 0.50 and the hemispherical emissivity e is 0.3. Representative conditions correspond to a surface convection coefficient h of 20 W/m2 · K, a solar irradiation G s of 700 W/m2, a sky temperature of - 10°C, an atmospheric temperature of 30°C, and a relative humidity of 65%. The roof may be assumed to be well insulated from below. Determine the roof surface temperature without the water film. Assuming the film and roof surface temperatures to be equal, determine the surface temperature with the film. The solar absorptivity and the hemispherical emissivity of the film-surface combination are aS = 0.8 and e = 0.9, respectively.

Reference no: EM13858439

Questions Cloud

Paper for quantitative analysis for business class : Reflection Paper for Quantitative Analysis for Business Class. Write a one page reflection paper, share the most important lesson or concept
Strategic plan for a health care organization : Analyze the steps involved in building a strategic plan for a health care organization and determine which step is the most difficult to get execute correctly
The importance of labor-management relations : The importance of labor-management relations, and how they differ around the world
What role marketing may have played in your seeking care : Determine if your situation followed the five steps of the buying decision model and what role marketing may have played in your seeking care
Maintain a cooler environment in non-conditioned buildings : A roof-cooling system, which operates by maintaining a thin film of water on the roof surface, may be used to reduce air-conditioning costs or to maintain a cooler environment in non-conditioned buildings. To determine the effectiveness of such a ..
How long will it take to gather the required data : Include a time line of activities and a duration for data collection. How long will it take to gather the required data? How long will each participant be required to devote to fully participate in your project
Proportion of shafts with a diameter : For this process what is the proportion of shafts with a diameter between 19.89 mm and 20.00 mm?
What is your batna? reservation price? target? : What is your BATNA? Reservation Price? Target?
Describe outlet switched from two switch locations : A duplex receptacle with one receptacle outlet always hot and the other outlet switched from two switch locations. The receptacle has two controlled outlets, must be powered through a switch control (SPDT), include all phase, neutral and grounding..

Reviews

Write a Review

Civil Engineering Questions & Answers

  Crash at a railroad crossing

Due to a crash at a railroad crossing, an overpass is to be constructed on an existing level highway. the existing highway has a design speed of 50 mi/h.

  Another alternativeis an anodized metal exterior attached

HJ Heinz Corporation is constructing a distribution facilityin Italy for products such as Heinz Ketchup, Jack Daniel's Sauces,HP steak sauce, and Lea & Perrins Worcestershire sauce. A15-year life is expected

  Calculate total mass of sludge dry solids generated per day

The flow rate of the treatment plant is 2,000 m3/d. a. Calculate the mass of sodium bicarbonate (NaHCO3) that would be required per day to replace the alkalinity consumed.

  Determine what is the angular rotation rate of the car

A car is travleing towars a 20 degree slope at 60 mph. The wheels have a radius of 12 in. and the car's wheelbase is 100 in. What is the angular rotation rate of the car immediately after the front wheel contacts the slop

  How deep is the water level in the second culvert

A rectangular culvert 4 feet x 6 feet is running full and discharging 3,500 cfm. There is no friction loss. Find the velocity in fps. The culvert empties into a 10 ft wide culvert and the velocity reduces to 0.6 fps.

  Determine the force supported by the hydraulic cylinder

A Steel plate weighing 205 lb with a center of gravity at point G is supported by a roller at point A,a bar DE, and a horizizontal hydraulic cylinder BC. Negelcting all weights of all members except for the plate,

  What is the percent volatile matter in the sample

A suspended solids analysis is run on a sample. The tare mass of the crucible and filter is 55.3520 g. A sample of 260 mL is then filtered and the residue dried to constant mass at 103 degrees C

  Find the bod5 of the final effluent using the nrc equation

A two-stage trickling filter plant treats 291.7 m3/h of municipal wastewater that has a BOD5 of 200 mg/L. The two filters have equal dimensions (depth = 1.68 m; diameter = 21.3 m), and each has a recycle ratio of 1.0

  Determine the most economical alternative of return analysis

Using Rate of Return Analysis, determine the most economical alternative below. Assume a minimum attractive rate of return of 6%, and a 5-year life with no salvage value for each. The alternatives are mutually exclusive

  Illustrate and annotate the lever system

a wheel barrow is used to lift a 200lb load. the lenght from the wheel axle to the center of the load is 2ft. the length from the wheel and axle to the effort is 5 ft. illustrate and annotate the lever system.

  Calculate the critical depth of a circular concrete pipe

calculate the critical depth of a circular concrete pipe with a diameter of 42 inches, a Manning's Number of .014, a slope of .025% and a flow rate of 10 CFS (cubic feet per second). The radius is 3.55 and normal depth is 25 inches

  What is the aftertax cash flow from the sale of the asset

Consider an asset that costs $712,000 and is depreciated straight-line to zero over its eight-year tax life. The asset is to be used in a five-year project; at the end of the project, the asset can be sold for $184,000

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd