What to ask before replacing the HVAC system in a building
Replacing an HVAC (heating, ventilation and air conditioning) system in an existing building affects space, energy, maintenance and the daily routine of those who use it. This guide gathers questions to frame the decision with the designer, the installer and whoever maintains the building. It is general information and is limited to the questions to ask: the solution comes from analysing each building.
What is there today and why change it
A good proposal starts from the building as it stands. These questions help to gather that information before solutions are compared.
- What is prompting the replacement: breakdowns, end of service life, comfort, consumption, noise or a change of use?
- Which areas are served, and where are complaints concentrated?
- Are the design, as-built drawings, manuals and maintenance records available?
- Has the building changed since the original installation, in occupancy, hours or layout?
- Which parts are meant to stay, such as ductwork, pipework, grilles, electrical panels and controls? Who has assessed their condition?
What changes in the building
In an existing building, the new installation has to find its place within what is already built. It helps to clarify these points early, together with whoever is proposing the solution. In a building divided into units under horizontal ownership, works that change its architectural line or appearance need prior authorisation from the owners' meeting, by a majority representing two thirds of the building's total value (Portuguese Civil Code, Article 1422(3)).
- Do the new units fit in the intended locations, with access for installation and future maintenance?
- Who confirms that the roof or structure can take the weight and vibration?
- Does the existing electrical supply serve the new installation, or does it need altering?
- How are noise near occupants and neighbours, condensate drainage (the water the units give off) and the ventilation of the spaces dealt with?
- Does the work alter the facade or roof? Does it call for any notice to the municipality?
During the works
In occupied buildings, how the work is organised matters as much as the technical choice.
- Does the building stay in operation? In which phases will the work take place?
- Which service interruptions are planned, and what temporary arrangement covers the affected areas?
- Who removes the old equipment and deals with the refrigerant and waste?
What to request in the proposal and at handover
Decree-Law No. 101-D/2020 counts space heating and cooling and ventilation among a building's technical systems (Article 3(x)). In buildings it covers, a technical system is replaced by technicians qualified for the purpose (Article 10(2)), with its scope identified and its energy performance assessed and documented (Article 11(1) and (2)). It is worth agreeing from the outset who handles these items.
- What is included, and what falls to other disciplines?
- What testing, adjustment and control checks are planned after installation?
- What documentation will be delivered, and what training will the system's operators receive?
- What maintenance does the system need, who can carry it out and which parts remain accessible?
- What are the warranty terms, and how do the equipment and installation warranties fit together?
Frequently asked questions
Which documents should be gathered before requesting proposals?
Plans, the design and as-built drawings where they exist, equipment manuals, maintenance records, energy bills and a description of complaints and hours of use. A complete starting point makes proposals easier to compare.
Who defines the right solution?
The solution comes from analysing the specific building, through design or technical consultancy, with the owner, the designer and the installer. This guide prepares that conversation.
Does the replacement have to be carried out by qualified technicians?
In buildings covered by Decree-Law No. 101-D/2020, installing, replacing or upgrading technical systems is carried out by technicians qualified for the purpose (Article 10(2)). The designer or installer can help confirm how this applies to the building.
How can I request a proposal or contact you?
You can request a quote or online consultancy in the Client Room, write to geral@afazerescuriosos.pt, call +351 21 145 1077, message us on WhatsApp or book a preliminary call to frame your request.
Need building services (MEP) engineering support?
Talk to us about online consultancy, design development and review, site supervision, commissioning or audits in HVAC and DHW, electrical systems, telecommunications and fire safety.