Did you know Cornelis Drebbel built the first-ever thermostat in the 17th century? The thermostat originated from a mechanical device that controlled the temperature of an incubator. In comparison, modern smart thermostats for room air conditioning can provide 0.1 degrees Fahrenheit of precision temperature control. They feature advanced technologies such as geofencing, scheduling, energy metering, personalization, and many other features to maximize comfort and efficiency.
A high-end thermostat with proper use and programming can save 10-20% on energy bills. However, a thermostat needs regular maintenance and calibration to perform at its most efficient form. When the thermostat is in good condition, the inhabitants will not have to adjust the temperature frequently, and the environment will remain comfortable.
Let's dive deep into how thermostats work and the steps we can take to maximize comfort and efficiency!
1. Understanding the Basic Functions of a Thermostat
Thermostats in our computers, smartphones, ACs, and appliances help us or our devices maintain temperature. Precision thermostats work actively by utilizing energy and other components to perform their function. Here are the details.
How a Thermostat Works
A thermostat is a device that detects the temperature of air or any other medium and controls its degree of hotness or coldness. Its operation requires temperature gauges or any other detection mechanism to provide feedback. In air conditioners, it detects the inside and outside temperature to sense whether cooling or heating is needed.
There are many types of thermostats, each with a unique working mechanism. However, there are three main categories:
● Mechanical Thermostat
The mechanical thermostat utilizes various mechanical devices to control the temperature. These include bimetallic strips in cloth irons and air conditioners.
Cornelis Drebbel's world's first documented thermostat was also mechanical from the 17th century. It utilized a mercury column that, upon heating, expanded in a tube, causing the mercury level to increase. A float on the mercury's surface started to move, causing a valve to open, allowing more air to come inside an enclosure. It controlled the flow of air to maintain the temperature inside an enclosure. However, in most modern applications, bimetallic strips are reliable, accurate, and long-lasting.
● Digital Thermostat
A digital thermostat utilizes instrumentation such as temperature sensors and hygrometers to detect atmospheric conditions. Electronics are the primary part of digital thermostats, and they are currently the most sold and used thermostats by product manufacturers.
These thermostats communicate through electronic signals. The electronics can include digital displays and a control system, meaning that the temperature sensor can be a semiconductor type in some devices.
● Smart or Learning Thermostat
The latest and most advanced form of thermostat is a smart thermostat. It uses a detection and control mechanism similar to a digital thermostat. However, it takes customization and control to a whole new level using WiFi and allowing remote control.
These thermostats allow users to control the temperature of their space remotely. Advanced features such as geofencing, voice control, and a learning mechanism allow automatic air conditioning to turn on/off based on your location. They can also automatically adjust the room temperature based on user preference to improve energy efficiency.
Other popular names for thermostats within these three categories are:
- Programmable/ Non-Programmable Thermostats
- Wi-Fi/ Wireless Thermostat
- Manual Thermostats
- Line Voltage Thermostat
- Low Voltage Thermostat
- Hybrid Thermostat
- Touchscreen Thermostat
- Data Logging Thermostat
Role of the Thermostat in an AC System
Air conditioners have many sensors and regulating circuits that ensure your indoor conditions remain comfortable. A typical air conditioning system includes a thermostat, temperature sensor, humidity sensors, and an inverter circuit for the compressor. We need to know about the psychometric chart to understand how these components work together to ensure comfortable temperature conditions.
Psychometric Chart and Comfort Zone
The chart provides insights into the thermodynamic properties of moist air. It is a tool that helps temperature control systems regulate and maintain air conditions and establishes a relation between temperature and humidity.
Scientists and engineers have found that humans generally feel comfortable within a relatively narrow range of temperatures (around 65-75°F or 18-24°C) and relative humidity (between 30-60%). The region within the psychometric chart is called the comfort zone. Thermostats ensure that your AC maintains the air temperature and humidity within the comfort zone.
Controlling Temperature
The thermostat is vital in AC systems and is the HVAC systems' brain or control center. A typical AC will have a thermostat to set desired air temperature conditions indoors. After the user sets the desired temperature, the thermostat takes the current value of the indoor temperature and compares it with the user's set conditions. If the set temperature exceeds the room temperature, the thermostat will start the compressor to initiate a cooling effect. Similarly, it will turn off the compressor when cooling is unnecessary and the room air reaches the desired temperature.
Controlling Humidity
Another critical job of a thermostat is maintaining the humidity level within the room. High humidity above 60% can become discomforting for the inhabitants. The human body cools by evaporating water through the skin. If the moisture in the air is already high, the body will stop releasing heat, which can make people feel hot. Similarly, low humidity below 30% can cause itching, dry skin, and flaking. It can also increase breathing difficulty for individuals with asthma or respiratory disease.
Thermostats use hygrometers to detect the in-air humidity levels. If the levels are too high, the AC will reduce its blower speed, and the thermostat will turn on the compressor to enhance condensation. If the humidity levels are too low, the blower will have an increased speed. Advanced ACs also feature humidifiers that can improve the humidity levels for comfortable living.
Impact of Thermostats on ACs
A high-quality thermostat is the key to maximizing your AC's reliability, efficiency, and comfort. But how do they do that? Let's examine how thermostats work.
Programming to Improve Efficiency
The thermostat takes feedback from the temperature and humidity sensors. It compares the feedback signals with the user settings. It then stops the compressor within the defined start and stops temperature setpoints, which are the thermostat's differential temperature settings. The compressor's start and stop need to be smart, as a larger band can cause a significant fluctuation in temperature between on and off cycles.
Modern AC systems come with inverter technology that does not turn off the compressor. The thermostat reduces the rotational speed of the compressor to facilitate cooling or heating output. It is highly efficient and allows better control of room temperature. There are no large turning ON/OFF cycles. As the thermostat does not let the AC deviate its temperature widely from the setpoint, it improves the overall efficiency of the AC. An inverter-based AC consumes less power to provide the same output as a standard AC.
Ultra Comfortable Environment with Smart Thermostat
Modern smart thermostats use internet and smartphone technology to provide a welcoming home or office. They are highly energy efficient owing to the following features:
- Individual Preference:It allows the user to customize temperature and humidity control for different times of the day. The user can load their profile for their room to adjust the AC according to their preference.
- Customizable Schedules:If you have air conditioning in your office or home and get in and out at specific times, you can use customizable schedules. Smart thermostats allow users to set the AC parameters according to their routine.
- Geofencing:Smart thermostats with WiFi communicate with the user's smartphone. It constantly checks the user's location. If the user is within a specific distance from their house or office, then the thermostat will turn ON or turn OFF the AC. If the user enters the circular geofence around the house, the thermostat will turn ON the AC for a more welcoming home atmosphere. It also turns the AC off to save energy when you leave the same geofence.
- Welcoming Home:Smart thermostats' welcoming home feature combines geofencing and scheduling to provide the most accurate temperature conditions when you enter the house. There is no initial discomfort in starting the AC and waiting for the right conditions to kick in.
- Adaptive Programming:A smart thermostat will also feature innovative programming that learns your habits and temperature requirements. If you increase the temperature for sleep, the smart thermostat will automatically know the pattern and adjust the temperature for you next time. In retail, sellers also call them learning thermostats.
2. Thermostat Installation and Maintenance
To ensure that the thermostat works at its maximum potential, the user or professional should perform its installation and maintenance properly. The installation location can significantly impact the performance of the AC unit.
The Importance of Proper Installation
The installation of a thermostat can affect its ability to work efficiently. Here are the key aspects to consider when installing a thermostat:
- Location:If your thermostat has a built-in temperature sensor, it is essential to place it at an accessible location. Install it in a room that is the most busy or used.
- Height:The sensor should be at least 5 feet above the ground for representative temperature conditions.
- Avoid Sunlight:Sunlight can disturb the thermostat's calibration by heating its temperature sensor above the room temperature, causing the air conditioner to run constantly. It can also damage the thermostat's internal parts.
- Keep Away from Heat or Cold Air Outlets:Your thermostat should be away from the air supply ports, radiators, windows, or any other source of cold or hot air. It can also deviate the thermostat from regular operation and cause major efficiency issues.
- Follow Manual:Smart, digital, or mechanical thermostat manufacturers provide comprehensive installation manuals with tips to ensure efficient operation. Review them to find the optimum installation position for the best results.
Regular Maintenance and Calibration
As with any equipment, some thermostats also need regular maintenance and calibration. Whether you have a mechanical, digital, or smart thermostat, all require regular maintenance and calibration for improved accuracy.
Cleaning: Dust can accumulate inside the thermostat, hindering its ability to detect the temperature accurately. If the dust increases, it can also lead to complete failure of the thermostat. So, cleaning the thermostat's interior once every six months is suitable for efficient operation.
Replacing Batteries: Wireless thermostats may have batteries to power them. A low battery can cause the thermostat to malfunction. Replace the batteries when the low battery signal lights up on the thermostat.
Calibration: The material inside the thermostat can degrade or change properties with time, causing the calibration to lose accuracy. Calibration is essential for any mechanical, digital, or smart thermostat.
Software Updates: Smart thermostats have built-in software that performs checks to improve their working mechanisms. The thermostat can program itself to improve efficiency and, in some cases, recalibrate itself. Always keep your thermostat software updated to the latest version.
3. Conclusion: Optimizing Your AC Use Through the Thermostat
Thermostats are a vital part of AC systems. They provide a balance between comfort and energy efficiency. Modern inverter-based AC maximizes comfort by utilizing advanced smart thermostats that feature scheduling, geofencing, home welcoming, adaptive programming, and personalized profiles to suit user requirements.
Modern thermostats can turn off your AC or reduce its output based on user activity and time. It can even track you leaving the house with geofencing to automatically turn off the AC unit. It can also turn it back on for maximum comfort when you're within a specific distance from your home.
FAQ
- How is my thermostat compatible with my AC?
To see if a thermostat is compatible with an AC, you need to see which communication protocol it uses, wired or wireless. The voltage, number of stages, cooling, heating, and manufacturer compatibility should be the factors to consider for compatibility with AC.
- Can a smart thermostat save me money on my energy bills?
Yes, smart thermostats can significantly reduce energy bills. They can turn on/off the AC or heat pump based on user location, time, schedule, personal preference, geofencing, and adaptive programming, drastically improving the efficiency of the cooling or heating unit.
- What is the best placement for a thermostat in a home?
The thermostat should be in the busiest room, away from sunlight and cold/hot air drafts. The user should install it 5 feet above the ground where irrelevant factors do not influence its temperature sensing capability.
- How do I troubleshoot a thermostat that isn't responding?
Start by checking for batteries, main supply, and WiFi availability, inspecting the wiring, and restarting the smart thermostat. If you cannot find any problems, contact the thermostat manufacturer's customer support.
- How often should I calibrate or replace my thermostat?
Calibrate every 1-2 years and replace after 5-6 years. However, these numbers are for reference as many factors influence calibration and replacement needs. Usage frequency, product quality, environmental factors, and power fluctuations can affect these numbers.
