**1. Introduction**

Historically, construction has been a wasteful process that sometimes could be automated or anyhow upgraded. Particularly, the manual installation of asphalt roofing rolls has several efficiency issues and its susceptible of being developed such as: safety and workers' health, installation speed, emissions, and quality of installation.

Currently, as experts in the field can ensure, installation of asphalt roofing rolls is usually carried out manually. The operators must accomplish several tasks: choosing the position of the rolls, calculating how many rolls are needed, getting them unrolled on the ground, activating rolls bonding with the surface by heating them, and ensuring everything is glued tight. In addition, during manual installation, there is not any heat control or measuring, since heat torches are hand-controlled by the workers themselves, which sometimes leads to an excessive application of heat and energy loss. Using the

explained current method, an average of 20–25 installed rolls per worker a day is only achievable. The poor work capacity of manual installation has uncovered the necessity to look for new systems or equipment that makes the process easier and more efficient.

Most of the devices designed to assist in these tasks are based on one or more torches. SO2 and CO2 emissions generated by gas burners must be diminished as much as possible. Environmental administrations are heeding roofing processes in order to reduce emissions. Emission factors in the manufacturing of asphalt [1] were devised by the Asphalt Roofing Manufacturing Association (ARMA). A measurement of 75.2 kg CO2 per roll was done [2] and determined that the responsible for the greater number of those emissions was the installation stage. Six million tons of asphalt per year are used in this installation process, which produces a large amount of CO2, SO2, and other non-eco-friendly emissions.

An alternative option to gas burners [3] could be infrared heaters, but a high electrical power source must be available, so its usability is limited. Therefore, the most polyvalent solution is to optimize heat transfer from torches, burners to asphalt rolls and, thus, gas expense.

Roofing workers' health must also be secured besides installation speed and gas consumption. Workers do not usually employ safety prevention equipment at the expense to improve their speed while performing manual installation. This practice also increases the risk of accidents. A proper way to prevent injuries is to design systems and equipment for efficient operation [4]; fatalities and occupational illnesses also can come from a non-designed bad posture during manual roofing.

In this book chapter, a state of the art is made of the main patents and products for the improvement and assistance in the installation of asphalt roofing rolls, based on both torches and infrared heating. Then, two new systems based on torches and infrared heating are described and compared with previous systems. This novel equipment permits the operators to work in more secure conditions avoiding occupational injuries. It must be lightweight and usable on any class of roof, will increase installation speed, and optimize gas and electricity consumption. Consequently, this new equipment even supposes a human factor improvement because while working, humans are also an emission source (eating, creating waste, using electricity, etc.), so, if the working time is reduced, so will be worker's impact.

In contrast, infrared heaters can supply steady heating power, free from the need of fuel burners. Infrared heaters are electrically powered and driven. That power could have been obtained from green energy sources, and also it is cleaner and safer for operators in their workplace. Enhancement of infrared heaters can also imply large heat transfer rates [5].

The designed new equipment is based on a trolley, which ensures the installation of asphalt in a cleaner, faster, and safer way. One version of the devices incorporates eight infrared heaters located radially and longitudinally around the asphalt roll, while the second version has a set of five parallel torches located in front of the roll to heat the asphalt up. Operators do not have to lift or unroll asphalt rolls, since they are directly placed on the floor and unrolled by auxiliary wheels as the same operator controls heat application. This conciliates a uniform and continuous roll heating to properly stick onto the ground, at the same time it keeps unrolling. Moreover, to guarantee the adherence of the asphalt in those places where the rolls overlap, the equipment counts with two small compaction drum rollers in both lateral sides.

The mechanical and thermal design of both models is presented, comparing heat transfer efficiency with computer fluid dynamics (CFD) simulations and calculations. Furthermore, some photos of the prototypes and operational tests are provided, demonstrating the advantages of its use rather than using manual installation. A comparison of these new systems with previous patents and commercial equipment is given in conclusions section.
