You might be wondering what the connection between heat shrink wrap and PVC is, but both are widely used materials in modern day construction. In particular, both have a connection for use in electrical engineering.
Polyvinyl Chloride (PVC) is commonly used to create the tubing which protects electrical wires. PVC is formed by polymerizing the monomer vinyl chloride, creating a rigid chain of carbon atoms. For its application as insulation for electrical wires, PVC needs to plasticized. With plastic additives PVC becomes flexible enough to protect the wires even when they bend. However, the plastic additives can become a cause for concern.
In construction the major concern with electric wires that have plastic additives is the release of HCL gas when fires destroy a building. However, in areas where smoke is a major hazard, PVC free insulation is preferred. So long as air is cool enough to be breathed the HCL breaks down onto surfaces, making it unavailable for inhalation.
Despite the concerns inherent with burning PVC, the insulation is also prized because it is more flame retardant than other materials. Like PVC, heat shrink tubing has a certain degree of heat resistance. Where shrink tubing differs from PVC is in the result of heating it up.
When heat is applied to shrink tubing two different things can happen. In one instance, a material with many monomers will be heated until they polymerize. When the monomers polymerize the material's density increases as the volume decreases, causing the material to shrink around whatever it is insulating. In the opposite instance tubing is heated, expanded, and then allowed to cool after being mechanically stretched over the material being insulated. Thus when the material returns to its pre-heating size it will be tight around the insulated material.
The most common applications for heat shrink tubing are as insulation for small electrical wires in electrical components and also for computers. Many custom computers feature tower casings with windows and to make the wiring more aesthetically pleasing, manufacturers will use the heat shrink tubing to clean up the appearance of the computer insides a bit, thus preventing a seemingly random winding of wiring.
The tubing can also be used to protect conductors, protect exposed ends of wires, and also protect joints and terminals in electrical engineering applications. Since it can be used for so many different applications the tubing will often be color coded to facilitate easy of system identification when servicing components or computers.
To find an electrical contractor, you must first determine the type of work you need done in order to get the expert in that sub-section of the field. For instance, if you want to set up emergency power as back-up in case of an outage or failure, then you don't need an electrician who specializes in outside work only, like power line construction.
Similarly, if there is infrastructure work needed to be completed, an electrical worker who can set up your home automation service would likely not be able to implement electrical infrastructure such as power line construction.
You can either post your project on sites created for this purpose, where electrical contractors will place bids, or you can research your choices by obtaining word-of-mouth references and searching online. To jump-start your search, use the phrase "electrical contractor" with your geographical location added, so if you live in California, for example, your search term would be: electrical contractor California.
If you are too broad in your search (using "electrical contractor USA") or too narrow (using "electrical contractor San Jose") you will not obtain optimum search results. In the first instance, there will simply be too many responses to make it possible to look through; in the second, you may lose a state-wide contractor that has branches in several cities.
Therefore do the state search first (such as "electrical contractor California"), and from the first ten or so pages from that response, you can whittle down to your immediate town or county.
No matter how you actually find an electrical contractor, you need to protect yourself, and some suggestions include: obtain the contractor's business license number and make sure you call the local licensing office to verify that company's standing.
Remember to search the Better Business Bureau, where you can discover if there were any complaints filed against the electrical company. Call the insurance agent that represents the contractor, to confirm that their public liability and property damage coverage is in full force and effect.
As important as all of the foregoing, ensure that you obtain past client names and contact information from the contractor, and make sure you speak to these people. They were once in your position, searching for a reliable electrical contractor and have given permission to the one you are interested in hiring to be contacted as a reference.
Use this source, and take up any invitation given to see the work in person. Ask about everything: the bid or estimate; the finished cost; the time frame given and the actual time it took to do the job. Once you have done your homework, you can make an educated choice.
HVAC is a vital component in the design and construction of buildings such as schools, hospitals and other large structures. Unlike the residential air-conditioning systems, HVAC incorporates filtration units and other large scale applications for industrial type usage.
One specific HVAC part used by contractors is the semi-hermetic compressor. It is commonly installed for use by the commercial refrigeration, as well the commercial and residential, air conditioning industry.
Copeland compressors have been in service since 1986. They are famous for their patented Scroll compressor, offering hermetically sealed (airtight) units that resist corrosion from dirt, dust and other airborne particles. This item and hundreds more comprise the inventory of an HVAC part supplier.
From commercial to residential needs, a specific HVAC part may, at times be difficult to locate. Some businesses have maintenance departments that handle the HVAC systems. The homeowner or smaller business owner, however, that needs access to an HVAC part can usually find the item on the Internet.
Whether a Ducted Reverse Cycle/Refrigerate or Evaporative Cooler system, HVAC parts are needed for their operation and effectiveness. The advantages held by the first example are the ability to heat and cool the entire home and may last for years.
One disadvantage is cost. Another is that during operation it may lead to stale air within the home. This can be addressed with the installation of a fresh air inlet which is required in commercial applications.
The second example uses air flow over wet sheets used primarily in commercial buildings. It is inexpensive to operate but will not function in humid weather conditions. The dampness brought into a building can cause problems by producing mold.
Semi-hermetic compressors function to compress gas by diminishing its volume. Once compressed, the gas increases in temperature and it is the method of managing the gases in an HVAC unit that determines the heating or cooling properties.
For an HVAC part installation to be successful in a complete system, the following conditions are necessary for its effectiveness and functionality:
* It needs proper room size for air-flow
* Static air pressure drop across the handler meeting specifications
* Sealed duct-work providing proper air flow
* The return system sized for correct return air flow.
* Sealed return duct-work and balanced air flow between supplies minimizes temperature gain or loss between air handlers and room registers
* Properly charging with refrigerant
* Proper burner and draft operation
With all HVAC installations, the parts and related tools for a successful system are determined by the skills of those responsible for the final inspection. When a homeowner seeks to install or upgrade their residential system, the HVAC part to complete the job can be easily obtained through an online HVAC supplier.
From compressors to gauges, the online source for HVAC supplies is only a click away to place the order and arrange for shipping if needed. A good supplier has all the details you need.