HVAC Controls: All You Need to Know

HVAC stands for heating, ventilation, and air conditioning. It is a system used to control the temperature and humidity of an area by moving air indoors and outdoors. Not only does it keep you warm during winter and cool on hot days, but it also maintains proper ventilation.

Suppose you are planning on installing an HVAC system for residential use. You should have complete knowledge of HVAC controls to realize the full potential of your investment and ensure that the system is operating efficiently. Even if you already have an HVAC unit installed, it’s likely you’re not aware of all that your HVAC control system offers.

Worry not; this article covers all the essentials required.

What Are HVAC Controls?

Just like your brain makes decisions interpreting different external signals, a controller takes commands via manual input or sensor signals to carry out specific tasks. HVAC controllers and most terminal unit controls can be a little complex, but for residential use, you only require an understanding of the basics.

You rely on these cooling and heating systems to make a living area comfortable, especially during the hottest and coolest days. HVAC controls are built in a way to be able to cater to the fluctuating environmental needs and handle even the worst-case scenarios. Several variables affect HVAC control usage. These include changing temperature and humidity, building occupancy, solar heat loads, new equipment, etc.

HVAC controls help the unit react to these changes effectively and ensure the temperature is adjusted to make living conditions comfortable and safe, not only for people but also pets and perishable food items. HVAC controls maintain temperature and reduce unnecessary energy expenses. In addition, HVAC humidity control allows you to manage the moisture in the air so that you do not feel too dry or tacky.

Starting from the simplest HVAC controls, you can turn the system on or off using the On and Off controls. For example, let’s suppose it has been raining outside all day, and the weather is pleasant; you can simply turn off your HVAC system to avoid energy wastage.

Other controls include time schedules, set points, logic, timers, trend logs, and alarms. The programmable nature of these HVAC controls allows for customizable use. They have analog inputs to measure temperature, humidity, or pressure, and digital ones that control airflow based on settings such as hot or cold!

Elements of a Control System: How Do HVAC Control Systems Work?

An HVAC control system, from the simplest room thermostat to the most complicated computerized control, has four basic elements: sensor, controller, controlled device, and energy source. Here is what they do individually:

Sensors

Sensors are the key components of any control system. In order to make smart decisions, a controller needs input from sensors and compares it with its setpoint. Without them, it is impossible to monitor and regulate the indoor climate. For example, different types of controlled variables crucial for an HVAC unit include temperature, the flow of the air, humidity level, etc. If the set point temperature is 73, the sensor will detect the current room temperature, and if it is higher, it would start cooling.

Controller 

A controller (or a thermostat) is a device that regulates the behavior of a system. It takes in input from sensors and processes that information to generate an intelligent output signal. Then, the required action is carried out. For example, when the temperature rises above a certain level, the sensors detect it and send a signal to reduce the temperature to cool down the place.

Controlled Device

After the sensors collect information and relay it to the controllers, the controllers direct the dedicated device to perform specific actions. The HVAC control module is responsible for directing the output devices. This computerized system governs all operations to adapt to changes in the environment so they can maintain desired conditions.

Source of Energy

There are two main types of control systems: pneumatic and electric. Both of them require power to operate. The HVAC system in your home is powered by electricity, and the energy source for that electricity is your local utility company. But did you know there are other options for powering your HVAC system?

One alternative energy source is solar power. Solar panels can be used to generate electricity that can then be used to power your HVAC system. Solar power has several advantages, including being renewable and environmentally friendly. However, it is more suitable for commercial use and requires a substantial installation cost.

Types of HVAC Controls

There are multiple types of HVAC control. All of them have their own advantages and limitations. Ultimately, deciding which type of HVAC control system to use depends on your specific needs and requirements.

• Pneumatic Control

Pneumatic control systems are powered by compressed air. Pneumatic controls are the most common type of HVAC control. They help HVAC work by providing a way to regulate the temperature and humidity in a space automatically. By using sensors and controllers, pneumatic control can help maintain a comfortable environment while saving energy. They are simple to install and maintain. They are also less expensive than electronic controls. However, pneumatic controls are not as accurate as electronic controls, but they can be calibrated to compensate for inaccuracies.

• Electronic Control

Electric control systems are powered by electricity. They are typically used in environments where precision is important, such as automotive manufacturing or aerospace engineering. That said, they are also widely used in residential areas. Electric control systems are more expensive to maintain than pneumatic control systems but offer greater precision and accuracy.

• Analog Electronic Control

Analog electronic control systems use electrical signals to control the various components of an HVAC system. They are used in multiple ways to help regulate the operation of these systems. One common use is to control the speed of fans and other moving parts from the HVAC control board.

This can help save energy and extend the life of the equipment. Additionally, analog electric controls can be used to monitor system performance and make adjustments as needed. Analog electronic control systems are typically more reliable and easier to troubleshoot than digital electronic control systems. Nonetheless, the precision may be compromised.

• Electronic Direct Digital Control (DDC)

DDC systems transmit information over the internet for remote monitoring and control capabilities. The most modern, state-of-the-art DDCs can also offer trend analysis to increase efficiency in your business or home’s mechanical setup – making them perfect investments!

Digital electronic control systems use computerized algorithms to control the components of an HVAC system. As a result, they often offer more precise control over the various parts of the system, making them more energy-efficient.

• Smart HVAC Controls

Smart HVAC control systems and IoT technology play a big role in improving the comfort, efficiency, and convenience of heating, ventilation, and air conditioning systems. By leveraging the latest advances in machine learning and cloud computing, these solutions have been engineered to operate efficiently and lower energy costs, as well as reduce maintenance demands. You can even make your ordinary HVAC unit smart right now by pairing it with a smart thermostat (for ducted units) or a smart AC controller (for ductless units).

Smart HVAC controls provide numerous advantages, such as personalized automated temperature settings, automatically utilized fan speed based on the room’s occupancy levels, or even schedule-based HVAC operation that maintains an ideal temperature throughout the day.

The integration of IoT into smart HVAC controls allows for more robust management and control as multiple smart appliances can be connected and operated together. By connecting thermostats to the internet via an IoT hub, these systems are enabled to access your preferences from anywhere, respond to voice commands from voice assistants like Alexa or Google Home with extraordinary accuracy, integrate with weather app to learn forecasts, and then optimize temperature settings accordingly.

Benefits of HVAC Control Systems

It is important to know about your HVAC controls as they offer many benefits when it comes to indoor climate control.

• Maintain Thermal Comfort  

Thermal comfort is the subjective experience of an individual’s physical comfort based on the temperature and humidity of the surrounding environment. It is affected by many factors, including air speed, mean radiant temperature, relative humidity, clothing level, activity level and thermal adaptation.

Humidity and temperature are important factors to consider when optimizing your thermal comfort. In addition to heating and cooling your home, an HVAC system also helps maintain comfortable living conditions by removing excess water vapors that contribute to indoor humidity. Moreover, you can create zones for personalized

• Maintain Optimum Indoor Air Quality

IAQ can be compromised due to a host of reasons. You must watch out for any pollutants seeping into your house for a healthy lifestyle. HVAC control systems can be an effective way to minimize the harmful effects of these pollutants. They are designed to keep you healthy by constantly recycling and purifying the air you breathe.

• Reduce Energy Use 

A more efficient HVAC system consumes up to 20% less energy. With the help of sensors, there is no need to repeatedly adjust the temperature manually. By investing in the latest HVAC technology, like a smart thermostat or a smart AC controller, you are directly contributing to acting on climate change. It reduces the carbon footprint as well as electricity bills as your AC never runs unnecessarily. It is a win-win situation for both the consumer and the environment!

• Identify Maintenance Problems 

Smart HVAC systems give you even more control and offer a variety of benefits. When combined with smart technology, it can help prevent problems before they arise. For example, Cielo smart AC controllers send alerts when air filter cleaning is due.

Some smart thermostats even detect if the AC is not performing well, which could be due to defective parts. With timely measures, you can prevent maintenance cost and improve efficiency.

Make The Most Out of Your HVAC Units

If you’re in the market for a new HVAC system or just looking to get more out of your current one, it’s important to understand the different types of HVAC controls and how they work. Understanding the controls might initially feel overwhelming, but getting the hang of all the terms and functions will definitely make it a lot easier.

The guide above should equip you with the basics to fully utilize the system’s benefits. If you were reluctant to spend on an HVAC unit, now is a perfect time. Invest in a good control system, and enjoy greater efficiency and comfort in your living space all year round.