Replacement, Retrofit or Upgrade
REPLACEMENT, RETROFIT OR UPGRADE SOLUTIONS
Commercial Buildings & Industrial Estates
Hotel Accommodation, Pubs & Clubs
Education, Schools & Childcare
Hospitals, Medical Centres, Aged Care & Health
Mine Site Buildings & Accommodation
THE LAWSON AIR APPROACH
We at Lawson Air consider every project as a unique opportunity to deliver the most cost-effective and energy-efficient solution for our customers. We work with building owners, site managers, maintenance managers as well as business corporate management to guide them through the process as well as the potential benefits of a more efficient and robust HVAC, Air conditioning, BMS or Mechanical System.
Heating, Ventilation and Air Conditioning (HVAC) systems are required to provide occupants of a building with suitable control of indoor temperatures. To maintain thermal control of what are often large volumes of air, HVAC systems typically have high levels of energy consumption. As such, improvements to the HVAC system’s ‘energy-saving efficiency’ are something that owners should consider. This guide isn’t designed to aid consumers with the introduction of new HVAC systems, but rather the potential benefits of retrofitting existing systems.
WHEN AND WHY SHOULD YOU RETROFIT?
An ageing HVAC system will become less efficient and require repairs more frequently. Due to this, retrofitting is necessary to prevent further loss in performance. If the HVAC system is over 10 years old, it may be nearing the end of its functional life. If this is the case, a retrofitting or repair is required to allow the machine to continue to run in subsequent years. Other signs that your HVAC system could be due for an upgrade could be high levels of energy consumption, poor indoor air quality and rising energy bills. When considering the capital cost of a retrofit, also note that replacing an outdated system may decrease energy costs by more than 20 per cent.
Retrofittings are usually implemented to reduce the HVAC system’s energy usage. Over time, most machines tend to lose efficiency with the wear and tear of repeated cycles. Concurrently, new technologies have been developed to allow for newer models to be increasingly efficient. On top of this, retrofitting an existing system is a fast and relatively simple solution to reduce energy consumption. Due to the large amounts of energy that HVACs consume, retrofits that prioritise cutting energy costs end up getting a return of investment within a few years.
The decision to retrofit may have been instigated by signs of an ageing HVAC. Over time, older systems start to drop in performance which may become observable with a decrease in air quality. On top of diminishing air quality, older systems may also start operating at louder sound levels. To maintain a high standard of air quality indoors as well as quiet operation, a retrofit may be the best solution. Also, if repairs are frequently being made to the HVAC system, then it’s a sign that components must be fully replaced.
Another key reason for a retrofit is for system longevity. Components of a mechanical system aren’t made to last indefinitely. Replacements are necessary to maintain an HVAC system. On top of extending the lifetime of a system, new technologies can be implemented to make the system more suitable for more modern requirements.
The main purpose of retrofitting is to ultimately improve the existing HVAC system by decreasing both operating and maintenance costs. These costs are reduced mainly by increasing the energy-saving efficiency of the system but, additionally, installing a Building Management System (BMS) can help centralise various systems. Any decision to upgrade or replace parts of an HVAC system should be evaluated beforehand as these mechanical systems are quite large and often integrated into the structure of a building. Because HVAC retrofits can be a complex procedure, it is recommended that owners and property managers look to external sources for help in determining whether a retrofit is necessary and for guidance when designing a retrofit.
A thorough evaluation of the existing HVAC system is important to determine whether a retrofit would be the best course of action and to identify any under-performing components before the implementation of the retrofit. A baseline assessment is to measure the system’s performance against desired performance rates which can usually be found online. A specialist engineer may be needed to assess more difficult parts of the HVAC system.
The sizing of a system is important as it correlates to its effectiveness when managing temperature. A smaller air conditioning system will use less energy but struggle to regulate temperature levels for a large area. In contrast to this, a larger system would generally be more effective for controlling temperature but use up more energy, costing the system efficiency. It is important that you only choose the sizes that are suitable for the corresponding area.
HVAC service providers typically estimate the technical requirements for a system to function depending on the size of the area it is meant to regulate. Contact the HVAC service providers responsible for installing your current system to check if they have any information available. If your building has undergone changes to the architecture that would affect the HVAC system’s coverage, then new calculations may have to be made.
The operating conditions of the building should be considered when choosing a replacement system or parts. When spaces are occupied by more people, the HVAC system has to deal with extra heat. The compressor in your HVAC system must be suited to the changeability of the HVAC system’s operating conditions. If the conditions within the affected area will vary, the correct compressor must be installed.
A Variable Speed Drive (VSD) is an important upgrade to consider as most HVAC systems don’t come equipped with one initially. VSDs save money by slowing down the rate at which the system operates depending on the required output. Although a VSD can save a lot of energy, its usefulness varies between situations. For systems that run non-stop at full capacity, a VSD is not needed. The same goes for low power systems as the return of investment is significantly lower than that of a larger, high power system. However, for large systems that run more variably, a VSD is a highly recommended upgrade that can save energy costs extensively. VSDs are also compatible with some types of water pumps and fans.
Motors are used in various HVAC equipment such as pumps, chillers and fans. When a motor experiences failure, it is usually rewound – undergoing an armature winding process that helps regain some or potentially all its original efficiency. With multiple rewindings, the efficiency of the motor tends to go down, thereby increasing operating costs. In many instances, it is better financially to invest in a new motor rather than lose money with less efficient but old motors.
Chillers are generally difficult to remove and replace, often leading to managers to avoid retrofitting them. They are often the most expensive piece of machinery in a building and may require the removal of walls and ceilings due to the system’s piping. Unfortunately, this leads to neglect from managements due to the disruptive and difficult nature of its replacement. Chillers consume high amounts of energy so an outdated system can lead to huge losses of performance, which translates into a loss of money. Replacing a chiller can cut massive costs on an HVAC system, especially if the chiller is more than a decade old. A new chiller operating at full capacity would require 40 per cent less energy than a fully functional 20-year-old chiller.
Air Handling Units (AHU) are used to distribute conditioned air throughout a building. AHUs take fresh air from outside to replace the dirtier air indoor. This system is necessary to maintain the comfort of individuals inside the building and so its components must be regularly checked for repairs or upgrades. Without a functional AHU, the oxygen and carbon dioxide levels, temperature and humidity may not be properly regulated. A viable upgrade would be converting to a Variable Air Volume (VAV) AHU which would regulate the amount of air depending on the occupancy and room temperature.
For most large buildings, heating is achieved through boilers. Boilers aren’t typically replaced that often due to their expensive cost and their relative durability. Some ways to determine if you have a boiler that needs to be retrofitted would be checking the overall condition, capacity and operating pressure/temperature. If a retrofit is necessary, consider replacing the boiler with a condensation boiler. Condensation boilers are more efficient than conventional boilers and should be considered when given the opportunity. It should be noted that condensation boilers have a corrosive condensate and so the drainage must be made with specific materials.
VAM Heat Recovery units are built to replace stale air with fresh air from outside while minimising the temperature loss during this exchange. This minimising of the temperature loss puts less of a load on the air conditioning system which results in energy savings. The heat exchange between the outgoing exhaust and the incoming supply air happens automatically and results in a reduction in energy loss. This automatic heat exchange can lead to approximately 30% less load to readjust the supply air to the desired indoor temperature. Most VAM units also come with a filter which removes most allergens contained in the air.
Programmable Logic Controllers (PLC) are small digital computers designed to automate a process. Within the context of HVAC systems, PLCs can be used to turn off the system when the desired air requirements are met. PLCs can also be programmed to change the system’s settings depending on the people’s schedule, to make sure energy isn’t spent on conditioning empty spaces. By changing the HVAC’s status when the occupancy levels are low or the building is empty, energy can be saved.
Motion sensors are an energy-saving option for buildings where occupancy may vary. The sensors detect when people are present to adjust the HVAC system settings depending on whether there is any motion. These sensors can sometimes be paired with PLCs to increase the automation of the process.
Night purge ventilation is when the air built up during the day is released during the night and replaced with fresh cool air. This method of cooling saves energy costs by requiring less energy to cool down in the morning. There is no running cost as this technology works just by allowing ventilation during the night, although ventilation is often built in the form of vents or windows. The schedule for the purges can be programmed on an hourly, daily and seasonal level. This method of cooling is more effective when the temperature difference between night and day is high.
Air-side economizers work by bringing outside air into the building and distributes the air throughout selected rooms. Due to the nature of how economizers handle air, the technology is not recommended in hotter climates as the technology is consistently reliant on a cool outdoor temperature to be effective. When the outdoor temperature is cooler than the indoor temperature, the refrigeration equipment can be halted, allowing the economizer to reduce the indoor temperature, hence saving money.