Designing an air conditioning system might not seem like a lot of work but it’s actually a very complex process.
That’s because every building is different. Even when we know straight away what type of system you need, we still have to work out the most efficient, cost-effective and attractive set-up for you.
In this post, we hope to give you an insight into the steps we take to design a high quality, bespoke air conditioning system.
Key Points of the Air Conditioning Design Process:
- Carry out a detailed site survey
- Calculate the required heating and/or cooling load
- Identify a range of suitable units with the required capacity
- Discuss the options with our customer and make recommendations
- Select the most appropriate units and any customisable options
- Identify the optimum positions for the units
- Draw up a quote for the installation
Sizing the Air Conditioning Systems
The required heating and/or cooling load is largely determined by the area of the space. As a rule of thumb, we would generally base our calculations on 120W per square metre.
Because ceiling heights don’t vary a great deal in commercial properties, the floor area is normally an appropriate measurement to accurately size each system. However, in some cases, particularly in high-ceilinged buildings like churches or concert halls, it’s necessary to work out the volume of the space.
As well as measuring the area, we take into account everything else that can affect the heating and cooling load. We have to consider heat transfer through walls, doors and roofs, existing heating and lighting systems, IT equipment and occupancy levels.
The size and orientation of the windows is especially important. South facing windows result in high solar gain, giving you a natural source of passive heat. This can have a major effect on our calculations.
After carrying out a detailed site survey, we have enough information to work out the required heating and cooling capacity. Once we’ve done that, we can start to identify the most suitable system for the space.
Different Types of Air Conditioning System
Depending on the capacity you need, there are several types of air conditioning system to choose from, as well as a number of manufacturers.
The cheapest system is a wall-mounted single split, which is typically used in server rooms, IT facilities and small offices. In our old office, we had two Mitsubishi Electric ZEN wall-mounted split systems to heat and cool our office throughout the year.
More expensive systems, such as VRF, VRV or ducted systems, are made up of several indoor and outdoor units. The indoor units are installed above the ceiling, leaving only the grilles visible. They’re common in large commercial facilities, including hospitals, hotels and office buildings.
Most of these large projects are specified in advance, meaning that all we need to do in the design stage is price up the installation. However, we often give technical feedback to other contractors and architects, suggesting improvements to the system’s efficiency, functionality and cost.
Additional Air Conditioning Design Considerations
When we design systems for our customers, we always take them through the different options. While the final decision is up to them, we use our knowledge and experience to give informed recommendations.
The majority of the time, the upfront installation cost is the most important consideration but other factors also come into play. Increasingly, energy efficiency is a big concern for our customers, given that it’s vital for reducing running costs and carbon emissions.
Businesses and residential customers often try to find a system that matches their interior (and exterior) design. We can achieve this by choosing the most attractive units and keeping the system as discrete as possible.
Getting down to details, customers may also ask for specific control functions and different styles of grille, as well as additional features like self-cleaning filters. Some optional extras can also be added at a later stage.
Positioning the Indoor and Outdoor Units
Once we’ve selected the units and components, we need to confirm they’re viable for the building. If the indoor units are going above the ceiling, we need to make sure the area is large enough to contain them.
We also have to take the structure of the property into account. In every building, there are places where units can and cannot be fitted, whether that is due to electrical wiring, plumbing or the materials used in the walls.
The outdoor units also need to be positioned carefully. Depending on the building and surrounding area, the best place might be on the roof, on the ground or mounted on an external wall.
All air conditioning units need a certain amount of space to operate properly and should be kept clear of dirt and debris. It’s sometimes necessary to fit cages around them to prevent damage and theft.
Designing the Route Between the Units
It’s also important to minimise the distance between the indoor and outdoor units as much as possible. Having a longer route connecting them is more expensive to put in place and may have a detrimental impact on performance. Manufacturers set limits to the distance between the units, which vary depending on their specification.
The route between the units also affects the installation time. If the layout or structure is problematic, even a short route might take longer to put in place. For example, if you occupy one room of a multi-storey office building and need an outdoor unit on the roof, we need to plan very thoroughly in order to make the installation feasible.
If the initial site survey is not done properly, the time and cost of the project could escalate dramatically. This has negative implications for both the installer and customer and is one reason we take air conditioning design very seriously.
If you would like B-DACS to design and install your air conditioning system, get in touch on 0141 773 3355. As always, we provide a free quote and are happy to answer any questions you have.