53 will not go into the general description of this topic here, which for the most part does not concern our profession. THE DATA REQUIRED FROM THE INSTALLER At point 2.3.8 of the prescriptions related to the project, there is a specific request that the designer must address to the lift installer, namely the preparation of a technical data sheet reporting the type of technology adopted (we assume it is required to specify whether the traction is hydraulic or electric and possibly the presence of an energy recovery system), capacity, travel, nominal motor power, energy consumption in the reference cycle, stand-by power. Similar data are required for escalators. These data are used by the designer to establish the lift’s annual energy requirement relative to the building’s square meters, necessary to calculate the global energy performance index, expressed in kWh/m² per year. The first four data are immediately definable or retrievable, while how to proceed with the last two requires further analysis. In principle, stand-by consumption could be measured on-site, and energy consumption in the reference cycle could also be measured and calculated based on the measurements taken, using ISO 25745-1 and 2 standards (or 3 for escalators and moving walkways), which are however costly to apply. Article 3 of the decree modifies the regulatory references of the previous DM 2015 by adding to the previous list the UNI/TS 11300-6 “Determination of energy requirements for lifts, escalators, and moving walkways”. This technical specification will allow us to calculate and provide the required data. In this article, we will stick to analyzing everything concerning vertical transportation systems that are not escalators or moving walkways, nor platform lifts. HOW TO ESTIMATE STAND-BY POWER Let’s start with the stand-by power required, which, thanks to the setup of the technical specification, is the simplest element to estimate; UNI/TS 11300-6, in fact, indicates criteria for estimating values rather than an exact calculation. The technical specification, in fact, first allows, at point 6.2.2.3, the estimation not of stand-by power, but of the daily energy requirement of control and lighting systems. As for the control panel with microprocessor board, which is now practically standard, the daily consumption is estimated at 1.2 kWh, so the associated power is 50 W. If an inverter is present, the technical specification estimates 1 to 2 kWh daily depending on capacity and speed of the lift. In the common case of a gearless electric system with 480 kg capacity and 1 m/s speed, the lower value is assumed, equal to about 40 W associated power. The expert Emanuele Emiliani, in an interesting article in issue 2-2023 of this magazine, referenced a real case where the power was estimated much lower, less than 25 W: the lift installer can still request a more precise figure from the supplier. For car lighting, if LED as is common today, the daily requirement is estimated at 0.7 kWh, with associated power of about 30 W. In this case too, a more precise figure can be obtained from the supplier. The technical specification considers the frequent case where the car light turns off automatically after a short interval from when the car stops at the floor. In this case, the requirement is estimated at one-tenth (i.e., the lights would stay on for 2.4 hours a day, a generally pessimistic assumption), thus 0.07 kWh; however, from the point of view of the power to be declared, it does not change. The technical specification then indicates to add to these values those of other present devices (which in the case of an electric lift with inverter, 480 kg capacity, and 1 m/s speed are about 120 W). Emiliani, in the cited article, estimated 20 W for the door operator motor, just over 20 W for floor and car displays, and just under 10 W for the photocell barrier, encoder, and safety circuits. Buttons and other signals, with the lift in stand-by (more precisely in non-operation condition), are considered off or negligible. Adding the values provided by the technical specification and those derived from the cited article, we would have a stand-by power of 170 W, while the figure specified in Emiliani’s example was about 115 W. If the lift is not electric but hydraulic, it generally does not have an inverter, so stand-by power decreases by those 40 W indicated by the technical specification. However, it must be taken into account that hydraulic lifts often have an oil heating resistor, which can require power of several hundred Watt when in operation. ENERGY CONSUMPTION IN THE REFERENCE CYCLE The technical specification describes, in point 6.2.2.2, the calculation of the energy requirement for an average travel cycle. A “cycle” refers to an average upward run and the corresponding downward run. The average travel cycle depends on the building’s characteristics and its traffic model, not in terms of the number of daily travels, but their nature. The starting point is the number of stops and thus the maximum travel distance the car can run: for example, a 4-stop building typically has a maximum distance of about 9-10 meters. However, unless there are only two stops, the average travel will be shorter than the maximum, as not all rides go from the lowest to the highest floor and vice versa. Note that the “standard” case described below may not match reality if one floor is much more frequented, such as in a medical office in a nearly residential building. The work (energy, in Joules) L required to move a mass P (in kg) over a height h (in m) is given by the formula: L=9.81×P×h/η where η is the system efficiency. For average cycle energy needs, h is the average travel and P the average load, which is less than the cabin’s maximum capacity since it rarely travels full—in fact, experience shows it often runs empty or with one person only, especially in universal operation systems common in Italy, even in non-residential buildings (except freight lifts, which often travel full). A table in the specification estimates average
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