Hotel Engineering Systems: Water, Electrical, and More

Posted on Apr 3, 2025 in Technology

Hotel Engineering Systems

1. Cold Water Supply System

From the aquifers, the pipes have specific pressure. Engineers know the pressure at each point, so when a hotel wants to connect to the public pipe, they can do so. Once connected, we add a counter that measures the water we receive. This water goes to a tank where it is kept. Then, water goes through a pump that sends it either to the base of the building (Constant Pressure System) or to the top (Gravity Fed System) to a tank from where the water will be delivered to the building by pipes. In a high building, it is more efficient to locate the tank on the top of the building. In the Gravity Fed System, once we pump the water to the tank, the water will be distributed by gravity to the hotel.

Components

  1. Tank: Keeps the water.
  2. Filters:
    • Softening – with salt filter
    • Chlorination – chlorine purifies water and kills bacteria
  3. Pipes:
    • Copper
    • Recyclable plastic, polypropylene
  4. Pumps: To pump water.
  5. Pressure Reducing Valves: For lower floors, we use pressure-reducing valves to regulate the pressure, with one per floor.
  6. Valves:
    • Keys to open and close
    • If the building is very tall, you need pressure-reducing valves (all bathrooms must have the same one).

2. Hot Water Supply System

Solar (sun) – very efficient and cheap – you can recover the investment in 7 months, but unfortunately, they occupy plenty of space.

  1. Solar thermal panels – water enters cold, and inside a metal box, we generate a greenhouse effect. Air gets extremely hot, heats the metal, and the metal heats the water. Then we need a pump to move the water, and so we are producing electricity.

Components

Same as cold water system +

  1. Boilers: Hot water is stored in hot water tanks. To avoid loss of heat from water despite the use of isolated pipes, we store this water to have water constantly moving and being reheated.

3. Rainfall Sanitary System

We collect the rainwater and send it out of our property. In some cases, we can recycle it. The rainwater flows into sewers (drainage). Then it could be treated for potable uses or not treated for non-potable uses such as irrigation.

Components

  1. Sewers: Collect water. Could be located on the ground level or on the rooftop.
  2. Vertical pipes: Polypropylene or polyethylene
  3. Horizontal pipes: Send the water to the city pipe.

4. Grey & Black Water Sanitary System

Components

  1. Syphon: After each WC, there is a V-shaped pipe which prevents hot air (bad smells) from escaping.
  2. Ventilation pipe: Air goes up and gets out of the hotel. We need different pressures in pipes to avoid strokes. (Vertical & horizontal – no PVC)
  3. Septic tanks:
    • Normal standard
    • Grease traps – different septic tank next to places with oils & Chemical waste (garage)
  4. City Pipe: Takes the water to an urban depuration plant

5. Wastewater Reuse

We can reuse that greywater by installing machines that clean and depurate that water. So we are including circular processes in the hotel to save money.

  1. Pretank: Container to store the greywater; we separate it from the black water that would go through another sanitary pipe.
  2. Depuration plant: UV ray filter – water is depurated (completely transparent)
  3. Post tank: Holds the water we are going to reuse.
  4. Pumps to push water: New water supply system that will bring the water back into the hotel (WC, laundry, gardens, water decorative features, fountains…).

6. Rainfall Sanitary System

We collect the rainwater and send it out of our property. The rainwater flows into sewers. Then it could be treated for potable uses or not treated for non-potable uses such as irrigation.

Components

  1. Sewers: Collect water. Could be located on the ground level or on the rooftop.
  2. Vertical pipes: Polypropylene or polyethylene
  3. Horizontal pipes: Send the water to the city pipe.

Elevators

Hydraulic Elevators

Hydraulic Elevators can only be used in buildings of six or fewer stories. They have no cables and push the car upward or downward using a massive piston inside a cylinder. The cylinder extends into the ground to a depth equal to the height of how much the elevator will rise. An electric pump forces oil into the cylinder through valves when the car goes down.

Traction Elevators

Held by steel cables that loop around a sheave at the top of the shaft, where the machine room is.

Centralized Systems

  1. Fan Coil Systems: To heat water – boiler, To cool water – chiller. One fan coil per room – water has to arrive at each one of them
  2. Radiator System: (only heat). It is a closed system that has only pipes, the cold water arrives at the boiler where it is heated and then taken to a hot water tank. The hot water travels through pipes until it reaches the radiators in each room. The water heats the radiator (metal).
  3. Multi-split System: Are ductless systems that offer superior performance, energy-efficiency and comfort in stylish solutions. Heating and cooling. Multi-split systems have temperature controls installed in each room. This equipment forces heated and cooled air through ducts that then deliver it to various parts of the home.
  4. Variable Refrigerant Volume (VRV) Systems: A large outdoor unit serves multiple indoor units. Each indoor unit uses an LEV (electronic liquid expansion valve) to control its refrigerant supply to match the demand of the space it serves. The outdoor unit also varies its output to match the communal demands of the indoor units it serves. These systems can be used for cooling only, heat pumping or heat recovery.
    Types:
    • Cooling only systems
    • Heat Pump systems
    • Heat Recovery systems
  5. Air Handling Units (AHUs): In places with too much pollution + too much noise. Consist of coils (through which steam/hot water or chilled water is circulated from central boilers and chillers), filters, fresh air intakes, exhaust air discharges, and sometimes humidification equipment.
    Types:
    • Draw-Through: the fan pulls the air through the mixing box, filters and cooling coil before discharging it from the fan outlet to the space to be conditioned or to the ducting network.
    • Blow-Through: the fan blows the air through the mixing box, filters and cooling coil before discharging them to the space being conditioned or the ducting system.

Decentralized Systems

  1. Split Systems: Locate only the evaporator and distribution fan in the guestroom and put the condenser and compressor outside the building on a balcony, roof or on the ground. The condenser has access to outside air, which it uses for heat rejection. Room air is circulated through the evaporator, where it cooled and dehumidified.
  2. Packaged Terminal Air Conditioning Units (PTAC): Essentially self-contained air conditioning units. Found in hotel rooms for the guests to set their room temperatures. Uses electricity to push the refrigerant through the unit and removes the heat and humidity out through the vent.
  3. Heat Pumps: Uses the refrigeration cycle for cooling and heating. The heat pump transfers heat by reversing the refrigeration cycle used by a typical air conditioner. Through a cycle of evaporation and condensation, the indoor coils are heated, and the air is pushed over the warm coils. From there, the warmed air is blown through the ductwork to increase the temperature in the interior rooms of your home.
  4. Electric Heaters: The heating element inside every electric heater is an electrical resistor, and works on the principle of Joule heating: an electric current passing through a resistor will convert that electrical energy into heat energy.

Electrical Systems

To take electricity from the city, we need to have a transformer which converts the high voltage electricity, which comes from electrical towers, into a low voltage which we use in the hotel. Once it is converted it goes through wires to a main or distribution panel, where we have circuit breakers (switches) that send the electricity to electrical lines in each panel of the hotel. These panels are called sub panels and the cycle is reappeared with more electrical lines ad sub-panels which go to machines.

Components

  1. Transformer: Regulates the voltage, makes it safe to use.
  2. Wires: Made out of copper and protected by PVC.
  3. Main panel: Has many circuit breakers (switches) which distribute energy to the building. Each switch is the beginning of an electric line.
  4. Circuit breakers (switches): Which distribute energy to the building (S)
  5. More Wires: That go from the main panel to other floors and other subpanels or installations as elevators, swimming pool, restaurants,…)
  6. Electrical fixtures: Final users of electricity, sockets, artificial lighting and minibars.
  7. Subpanels with certain breakers: In a hotel, each room has a breaker + a wire.
  8. Final circuits: That go into everything in the room (minibar, lightning, TV,…)
  9. Counters: Are electronic devices which are connected to the BMs and control the consumption of electricity. always at the beginning of the system to count the amount of energy we use + counters in every single level/floor.
  10. Back up generators (EPG – Emergency Power Generator): Every hotel has one (S) – this generator burns diesel so we need different tanks to store that diesel. It provides energy without electricity when there are blackouts.

Lighting

Types: General lighting, task lighting and accent lighting.

Sources

  1. Incandescent Lamps: Consist of a filament inside a sealed glass bulb. The lamp is usually coated to diffuse the light produced by the filament. They are very inefficient as only 30% of the electricity is transformed into light; the other 70% is lost in heating. They are characterized by short lifetimes, but they are capable of instant starting and restarting, low in cost and are readily dimmed.
  2. Electric Discharge Lamps: Generate light by passing an electric arc through a space filled with a special mixture of gases. It converts 70% of the energy into light, making it quite efficient.
  3. Light-Emitting Diode Lamps (L.E.D): Are semiconductor devices that produce visible lights when an electrical current is passed through them. They are the most efficient lamps as almost all of the energy (95%) is transformed into light. They are also the most expensive ones but long-term speaking they are worth it.