HVAC
Building Control
Fire Safety
Your friend in indoor comfort & safety systems
Home Company Services Case Studies References Agencies Daikin-Vrv Handbook Fires / Hotels Links Save Energy Contact Us
Eco Homes

Solar Water Heeating

Solar Electric Systems
Wind Turbines
Passive Solar Heating
Passive Solar Cooling
Water Conservation
Building Material
Ground Source Heat Pumps
Eco Cases
Save Energy
Solar Water Heating
Solar Electric Systems
Wind Turbines
Passive Solar Heating
Passive Solar Cooling
Building Material
Water Conservation
Ground Source Heat-Pumps
Green Hotels

Glass &Windows Selection

Standalone Systems
Grid Connected Systems
Hybrid Systems
Back-up Systems
Solar Cells
Solar Arrays
Inverters
Change Controller
Direct Systems
Indirect Systems
Thermosiphons
Draindown Systems
Pool Heating Systems
Turbines
Hybrid Systems
Grid Systems
Water Pumping
Using Wind Energy
Enviromental Aspects
Buyer's Guide
Solar Collectors
Flat Plate Collectors
Evacuated Tube Collectors
Concentrating Collectors
Transpired Collectors
Solar Control Systems
Big Hotel Fires
Hotel Fire Cases
Fire Hazard Classification
Hotel Sprinkler Systems

Hotel Fire News

Ask The HvacMan
Air Handling Units
Cooling Towers
Heat Recovery
Psycometry

Steam Generation

Which collector is suitable for which situation ?

The desired temperature range of the material to be heated is the most important factor in choosing the correct type of collector. An uncovered absorber is certainly not suitable for producing process heat. The amount of radiation on that spot, exposure to storms, and the amount of space must all be carefully considered when planning a solar array.

Vacuum tubes are in thermos bottles. You can pour in the hot coffee and it will stay hot for quite some time in the winter. This is because of the perfect insulation of a vacuum.

Then add a selective surface coating to reduce the black body emissivity. Then add a phase change heat pipe. Then add an insulated manifold with the heat tube condenser inserted. Flow water across the condensers and the laws of thermodynamics take effect-----the higher energy level ( heat radiation ) will move to the lower level of the heat transfer fluid. The heat transfer fluid again gives off its higher energy level to the potable water at the heat exchanger and voila---solar domestic water heating

Flat plate collector, vacuum tube collectors, batch tank collectors and coiled black garden hoses all do this. But, in cold climates only the vacuum tube heat pipe technology will do it with any efficiency or cost benefit.

It can be shown that a collector to ambient differential temperature of about 50 degrees Celsius is the point at which the evacuated tube collectors become a better economic value than the glazed flat plate alternatives. From 27 to 47 deg Celsius the evacuated tube collectors requires a lesser footprint than the glazed flat plate for the same energy produced.

For all applications requiring differential temperatures below 47 deg Celsius (eg Florida in the wintertime ) the flat plate glazed collectors may be the better value as they can be used in open loop configuration where the potable water is pumped directly through the collectors. The coiled black garden hose will also work out in such a warm climate. Vacuum tube collector applications requiring average differential temperatures of ~50 deg Celsius through below 50 degrees Celsius may require only 1/3 to ½ the surface area of the glazed flat plate collectors.

Another nice fact about the vacuum tube heat pipe system is the ease of installation. While they must be handled gingerly, they to not require a small elephant to hoist them up onto steep second story roofs. A homeowner can install a system working alone and save the contractor installation costs. Which must be factored into the cost efficiency of the device over its useful life.

The specific costs of collectors are also important. Evacuated-tube collectors are substantially more expensive (at 511,29 - 1278,23 Euro /m² collector surface) than flat-plate collectors (153,34 to 613,55 Euro /m²) or even plastic absorbers (25,60 to 102,26 Euro /m²). However, a good collector does not guarantee a good solar system. Rather, all components should be of high quality and similar capacity and strength.

 

 
 
Google
 
Web www.iklim.com
  Discuss on the Message Board
   
 
  http://www.iklimnet.com
 
Book & Magazine
Interstate Bank Fire
Beverly Hills Club Fire
MGM Fire
Firehause Magazine
Special Fires
Hotel Fires
Ship Fires
Industrial Fires
Warehouse Fires

Restaurant/Nightclub Discotheque-Fires

High Rise Fires
Fires
Fires ABC
Big Building Fires
Book About Fires
Fire Stats
Fire Board

Books About Fires

Hotels
Enviroment
Energy Save
Hotels & Legionella
Green Hotels
Hotel Design Books
Control Software