You’re starting a new construction project. How can you ensure the HVAC system is energy-efficient?

HVAC system energy efficiency starts from understanding the enegy needs or consumption profile and the climate conditions Then specifying the consumption profile as a requirement for the the HVAC, ensuring a design that allow for automatic shutdown when energy is not required. Implementing energy saving system and using as much as possible natural air or ventilation as a cooling medium.

In order to choose the right system it is important to perform a Mechanical System Analysis. In this report we provide the following information for multiple systems being considered: 1. Estimated costs: first cost, energy cost (based on a detailed energy model of the specific building), maintenance cost, replacement cost. 2. Net Present value analysis: shows 40+ year costs for the system. Cheaper systems needing replacement more often may be more costly long term. Energy efficient systems can also cost less over time. 3. Building effects: floor space required, weight of system (structural impact), ceiling space required, etc. 4. System capabilities: longevity, scalability, flexibility, redundancy, is it centrally maintainable, etc.

Before choosing the right system, you need to design the building in the right way. Limit the needs of energy by choosing well the windows, the wall insulation and inertia of your building. This will lead to less power needed in heating / cooling if the design of the building is good. Then you have to ask yourself if you want to treat the heat emission through hydraulic or air system. Hydraulic will be more compact but air system will give usually quicker response and allow easier/better cooling.

Optimising the HVAC system isn't a one-way simple method. From my own experience I like creating a preliminary HVAC load calc. that provides insights regarding the major contributors to the overall load. Once you write down the load breakdowns, you start suggesting strategies affecting the major contributors starting with the cheapest! Example: your building is crowded? Requires high Vent. Rates? Plot the annual climate profile and consider using an economiser rather than heat recovery...apply strategies 1 at a time and see how they build up. The next step depends on the building operations. Having a centralised system can result in higher diversity values if HVAC zoning is done correctly. And that's my personal approach.

Many years in the field and I have seen systems installed poorly and programmed just as bad, may as well saved some money and install a time clock! Keeping going for cheap installs and waste your money or look to have it done right from the off and it WILL pay for itself over time!

It's always better to check the qualification of the contractor. Cheap installation often means quick work and errors on the construction. In the best case scenario, it's a minor correction to do after installation but you could also have unqualified workers that would install in the wrong way your HVAC system and worse could also be accident on your construction site because of lack of security.

Each equipment of HVAC needs to be checked regularly. To keep the efficiency of the system and avoid loss of energy (thus money) but also to maintain the good conditions of work for the boiler/heat pump... and make it last longer avoiding premature refurbishment.

Power optimisation is most important factor for HVAC system. With efficient controls total power consumption could be reduced. Compressor being the main power consuming component need rpm reduction as and when needed. Controlled expansion valve for efficient sub-cooling and superheat controls enhances overall performance coefficient.

Before we just focusing on the upgrade HVAC, it's essential to understand the connection between HVAC efficiency and energy consumption. According to industry experts, HVAC systems contribute to roughly 40% of total energy consumption in residential and commercial buildings. here is some key note you have to consider When you are dealing with these kinds of challenges, first energy efficiency minimizes the amount of energy required to maintain a comfortable indoor environment,second utilizing energy efficient HVAC systems can lead to reduced energy consumption and lower utility bills, furthermore proper insulation and regular maintenance enhance the overall efficiency of HVAC systems.

In my experience, one problem that should be avoided is excessive noise from equipment. This must be taken into account in the design to avoid complaints and future problems.

Though I would usually recommend central system for HVAC, I used to work for a company that is providing interesting HeatPump to execute all HVAC in a decentralized way. Very usefull for the renovation of office building with labels like BREEAM/WELL ... There is no all fitting solution. Always consider different options for your building.