Introduction
A vacuum cleaner is a home electrical device that is used to clean floors and carpets. It uses an air pump to create a vacuum that sucks up dust particles and other dirt from the surface. This is mostly used as a home appliance. But large industrial vacuum cleaners are also produced.
History
Multiple sources are making different claims as to who first invented the vacuum cleaner. But many agree that the vacuum sweeper that got the patent was first invented by Daniel Hess in 1860 (Kautzman). This sweeper used the technology of having a water chamber inside the machine to clean the air and collect the dust particles. This technology of water chamber is being used in modern vacuum cleaners today. Various versions of vacuum cleaners were produced in the late 1800s. The most famous production was by Cecil Booth in 1901. This large vacuum cleaner was powered by an engine and was aimed at cleaning the whole house or building through large pipes.
The first electric vacuum cleaner that was small enough to be used inside a house was produced in 1907. William Hoover bought the patent rights for this machine and sold it door to door. Thus the vacuum cleaner as a home appliance became popular as early as 1908. (Kautzman)
Technology
A vacuum cleaner is a medium-sized machine that can be managed by a single person, although robot cleaners have also been produced lately. The vacuum cleaner usually has a chamber on the wheels and a pipe connected to the chamber. This chamber has the motor, suction pump, and water chamber or a bag. A wire usually connects to the electrical socket and the motor runs the suction pump. Ahead of the pipe, there is a brush and suction holes that suck the dirt and dust particles.
The vacuum is created through a difference in air pressure. The motor inside the machine lowers the pressure, and this causes the air to move inside the machine through the pipe. Hence the dust particles are pushed inside the bag, or water chamber. The dust is collected inside the chamber as it mixes with the water inside.
- Types: According to the air cleaning technology, there are different categories of vacuum cleaners; upright, canister, central, and extractor in-home purpose cleaners.
- Upright cleaners use the rotating brush and nozzle to rub the surface and gather the dust. A handle and a bag are attached to the machine. The motor inside also causes the brush roll to rotate which removes dust through rubbing, sweeping, and vibration. The dust is blown through the suction pump into the bag.
- The canister type is similar to the upright, except that it has the motor and bag in separate canister units. That makes it better able to keep the dust from being blown out in hot air released from the motor.
- Central cleaners are larger vacuum cleaners that have a bag and hose in the center, from which the suction pipes can be carried to different rooms.
Exhaust Filtration
The air that the motor releases need to be filtered from the dust particles that are sucked inside. For this various techniques are used.
Those cleaners having dust bags rely on the walls of the bag. The walls do not allow the dust particles to escape. Often an air filter is attached to the bag to help filter the air that is exhausted. Cyclonic separation is used in bag-less cleaners. In this technique, the air is spun fast around a chamber that forces the dust particles into the dust chamber. Water Chamber cleaners are getting very popular. They use a chamber that has little water, instead of having a dust bag. The sucked dust is mixed with water, and it is kept in the chamber while clean air is exhausted.
Question
How to improve the vacuum cleaner product?
Proposal
The exhaust gases from the vacuum cleaner make it very hot and dangerous for minors. A vacuum cleaner with an air condenser is introduced that would cool down the air before exhausting. Furthermore, the air should be cleaned before exhaustion. For this, a vacuum cleaner with a water chamber may be introduced. Advancement in this case is steam cleaner. Although it does not use the concept of vacuum, it looks like a vacuum cleaner in its operation and working. It is more useful in case of cleaning sticky dust particles that may not be separated by a simple vacuum cleaner. It has a disadvantage in that it gets very hot as it needs to heat the water inside to make steam that is used to clean the surface.
Data
The data is collected about injuries and breathing problems caused by vacuum cleaners. The first population (P1) is the data relating to injuries caused by normal upright bag vacuum cleaners in a particular year. The second population P2 is related to the new water chamber, heat efficient vacuum cleaner.
Assumptions: The assumptions are that the data has been collected randomly in the same states after the new product has been introduced. Only a few medical centers have been selected in each of these states before and after the introduction of a new product. It is assumed that after the new product is introduced, none of those injured were using old machines. Both samples are assumed to be normally distributed.
Hypothesis: We need to test whether the two samples are significantly different. For that, we can use an independent two-sample t-test.
Null Ho: X1 = X2
Stats
t – value = 5.651735
Compared with the table value at 28 degrees of freedom and 95% significance level, that is 2.0484, the t statistic is greater than the table value.
Conclusion
The null hypothesis cannot be accepted, hence there is a significant difference between the two samples.
The statistical Model
To test the hypothesis a statistical model may be devised. This statistical model will attempt to explain the acceptance of the new product, i.e. its rating, in terms of its price and technological innovation. The t statistic of the variable “innov” will test our hypothesis. This is a dummy variable, taking the value of 1 when the product is new (that it falls in P2) and zero when it is old technology.
Accept = α + β1 (price) + β2 (innov) + γ
The regression of accept was run on the values of price and innov. The values for accept are the product ratings by various research market websites. The results are in favor of the hypothesis.
Regression run on Stata 8.0.
The coefficient of price is small as expected. The demand of a product should be less correlated with its price. The t statistic of price is also very significant, against the 95% confidence value of 1.96. The value of special interest is that of the “innov”. The coefficient is very small, that is almost 0.1, but the t-statistic is very significant. The value of 3.67 against 1.96 explains that the innovation is definitely linked with the ratings. The constant is very large and that tells the noise is significant in the model. That implies that there are many other factors explaining the ratings that are not included in the model.
Final Conclusion
The hypothesis about improvement in the vacuum cleaner technology was tested by two techniques. Both t-test and the multiple regression give an indication that the new technology will prove to be highly acceptable by consumers and favorable for the manufacturers as well. Although many other variables could be included in the regression, the basic result needed was the t-statistic of the “innov”, that is already very significant.
Appendix A: Data used in regression
Note: The prices are assumed to be generally higher for the new models, and for those the value of innov is 1.
Bibliography
Robert Kautzman. Web.
H. Cecil Booth. “The origin of the vacuum cleaner, Transactions of the Newcomen Society”. 1934–1935, Volume 15 Vacuum Wizard. Web.