Air Conditioning & HVAC Surveys

Diagnosing performance, and starting the year with efficiency first

The first few months of the year have a habit of doing this. Energy bills are landing on the doormat and are getting more expensive.  Under the January 2026 price cap, a typical household in Great Britain is paying around £947 a year for electricity and £809 a year for gas, with the cap itself set at £1,758 per year. For commercial organisations the stakes are even higher because HVAC typically accounts for around 30–40% of a building’s total energy use, and ventilation, heating and cooling alone can consume up to 25%, 18% and 15% respectively.

At the same time, comfort complaints are far from rare. A 2025 survey reported by Workplace Journal found that 64% of employees regularly work in uncomfortable temperatures, and many also see clear signs of waste, such as heating or cooling left running in empty rooms and even windows open while systems are on. Better control isn’t just a “nice to have”. The same research notes that most employees believe improved temperature control could reduce bills.

Building resilience is rising up the agenda. The Climate Change Committee warns that towns and cities will become increasingly hot, with many existing buildings at risk of overheating during heatwaves and heat-related deaths potentially exceeding 10,000 a year by 2050 without additional adaptation.

So if this is you and you’re thinking, “Should we get our HVAC looked at?”, the most direct answer is “yes”.

HVAC surveys, what they really look at

An HVAC (heating, ventilation, and air conditioning) survey is a compliance must-do and a structured way of understanding how a system behaves day to day (not how it was designed or supposed to work in the operational manual). How it behaves now, with real people in situ, in real environments, with real schedules and real wear and tear. This includes plant condition, controls, zoning, airflow, maintenance history, and how the system responds when demand changes hour to hour.

A quick note on HVAC compliance

In the UK, air conditioning systems with an effective rated output of more than 12kW must be inspected at intervals not exceeding five years. TM44 inspections are there for a reason. They flag inefficiencies, poor control strategies and highlight opportunities to reduce energy use. These inspections are necessary under the Energy Performance of Buildings Regulations and focus on efficiency and appropriate sizing and control of systems. The issue is not a one off inspection itself, more often than not, it’s how often it becomes a formality. Often a report is produced, recommendations are noted, everyone nods in appreciation and then the report is filed away and nothing further happens. (Compliance is met (inspection done), but performance stays flat).

What surveys tend to uncover (almost every time)

Across offices, residential blocks, and mixed use schemes, we see the same themes cropping up. Controls on systems that nobody fully understands (and therefore don’t get used properly). Systems heating and cooling all turned on at the same time (yes it happens!). Setpoints that drifted years ago and were never questioned or addressed. Poor balancing that leaves some spaces freezing and others hot and stuffy. None of these are catastrophic failures, but are inefficiencies that can drain energy or begin to add cost over time. The results often see staff or residents opening windows in winter. Portable heaters being turned on under desks, coats being worn in the building and comfort complaints become daily moans over coffee.

Efficiency first – the fixes that usually pay back fastest

The good news is that many improvements, once identified, are usually achieved with low disruption.

• Tightening control schedules.
• Adjusting setpoints and deadbands.
• Improving zoning.
• Addressing basic maintenance issues like filters and coils.
• Sometimes it’s simply making sure systems are switched off when nobody is there, all of which reduce energy use, improve comfort, and extend plant life.

If you then layer in more sophisticated thermal modelling or overheating assessments, you begin to see how HVAC performance links directly to occupant comfort and future resilience. Increasingly, having the right evidence matters. A mentioned above, one trap clients fall into is treating HVAC surveys as one-off events. A snapshot in time that is great for a moment, but quickly forgotten and out of date. A stronger approach is to consider surveys as part of an ongoing evidence trail. Document what was found, record what changed and review outcomes. That way, when someone asks about efficiency, comfort, or compliance, the answer is calm and confident and supported by up to date evidence.

Where enevo can help

HVAC performance is not an isolated measure, it connects to energy ratings, ventilation effectiveness, air tightness, and overheating risk. To that end, enevo supports thousands of clients across that whole picture. From EPC assessments and energy and sustainability planning statements, through to ventilation testing, air tightness testing, thermal modelling, overheating calculations, and air quality testing. Our aim is to help clients not just to fix issues they may experience today, but to help support the development and management of buildings that perform consistently better over time. Fewer complaints, lower energy use and all backed with clearer evidence.

A sensible way to start the year

Use Q1 to make a promise to yourself over the measurement and monitoring of your buildings. Done well, HVAC surveys and monitoring create momentum, replace guesswork with insight and help building environments that feel better to be in, (which is more noticeable by residents than a written report). If efficiency and more comfortable building environments is the focus this year, this is a good place to start. Get in touch to see how we can help you achieve this as practically as possible.