Humidity Performance · Pillar 1
For decades, HVAC has been designed, sold, and rated around one variable: temperature. Humidity Performance is the case for giving the other aspect of cooling, removing moisture, its own target, its own equipment criteria, its own control, and its own proof.
Humidity Performance, defined
Humidity Performance is the intentional setting, control, and continuous verification of the humidity conditions a building needs to perform as intended, improving energy use, comfort, operations, and reliability.
In practice, it comes down to four principles: design a humidity target before you build, select equipment that can actually hit it, control it independently where it matters, and verify that it’s holding, continuously. It’s not a certification, a code, or a rating body. It’s a way of thinking about HVAC that a growing number of engineers, owners, and manufacturers — Mojave included — believe the industry is overdue to adopt.
This article is the first in a series laying out what that means, why it matters, and how it changes the questions worth asking about any building’s climate system.
The problem with measuring buildings by temperature alone
Ask almost anyone how a building’s climate control is doing, and they will answer in degrees. Thermostats are set in degrees. Efficiency ratings like SEER2, EER2, and IEER measure cooling delivered per unit of energy at standardized test conditions, they don’t tell you whether a system can hold a humidity target in the building it’s actually installed in. Comfort complaints get filed as “too hot” or “too cold.”
Humidity rarely gets a number at all, let alone a target. It is treated as whatever happens to come out of the cooling process, not something engineered on purpose. We call that incidental humidity control: humidity managed indirectly, as a side effect of cooling, and evaluated inconsistently, if it’s evaluated at all.
That gap has a cost. The IEA estimates that space cooling used around 7% of the world’s electricity in 2022 and produced roughly one billion tonnes of CO₂, and in humid climates a large share of that cooling energy goes toward removing moisture, not heat. A 2022 analysis published in Joule found that removing moisture accounts for more than half of the world’s cooling-energy emissions, more than lowering air temperature, with humidity’s share projected to grow to 67% by 2050 due to building efficiency improvements and increased ventilation rates.
Humidity’s reach goes well beyond comfort, too. It drives condensation and mold risk, refrigeration performance, manufacturing quality, building durability, service calls, and operating cost. In humidity-sensitive spaces like grocery, healthcare, and data centers, it damages product and equipment directly. In pharmaceutical and industrial production, it can mean lost product outright: a single humidity excursion can compromise a batch of moisture-sensitive tablets, powders, or components before anyone notices. Occupants feel it even when the thermostat reads “correct.”
Engineers have a mature, decades-deep playbook for sensible (temperature) load. The playbook for latent (moisture) load is comparatively thin, which is exactly the gap Humidity Performance is named for.
The industry has started to acknowledge this. Since its 2019 edition, ASHRAE Standard 62.1 has limited indoor dew point to 60°F in spaces served by mechanical cooling, checked at design conditions. That’s an important step, but a design-condition check is a starting point, not proof of performance. It says nothing about which equipment can meet the limit efficiently, how humidity is controlled day to day, or whether the building is still holding it three summers later.
The shift behind Humidity Performance is one engineers are already seeing in the field. In a recent ACHR News article, Mojave VP of Product Aaron Meles explains how tighter building envelopes have shrunk sensible loads while the latent load from ventilation and occupants stays the same. He also explains why separating the two is becoming a design driver. As he puts it, “Asking one coil to cool and dry at the same time is not effective.” For the engineering case behind that idea, read Humidity Control: The Growing Role of Low-Dewpoint Cooling.
The four principles of Humidity Performance
Humidity Performance rests on four principles, applied in sequence across a building’s life, from the first design meeting through years of real operation:
01
Design
Set the target before you build.
Insufficient temperature control makes a space a little uncomfortable. Insufficient humidity control harms people and buildings: mold, product loss, comfort complaints, and wasted energy. So, Humidity Performance starts with an explicit humidity or dew point target at design time, the same way a temperature setpoint already gets one. Similarly, latent loads or moisture removal rates should be calculated with as much careful attention as sensible loads.
02
Select
Choose equipment that can actually hit it.
A humidity target is only as good as the equipment chosen to deliver it. That means selecting systems on what they can actually do, dew point capability, energy performance, and behavior at part load and across real operating conditions, not just the peak-rated number on a spec sheet.
03
Control
Control it independently where it matters.
Humidity should be controlled on its own terms, not chased as a side effect of running the cooling coil colder. That takes two things: independent control, and a control sequence that’s set up and tuned for the building it serves. It also means controlling to the right variable. Relative humidity shifts with temperature: air with a 55°F dew point reads about 50% RH at 75°F but over 60% at 68°F, even though the moisture content hasn’t changed. Dew point and humidity ratio (grains of moisture per pound of dry air) measure the moisture itself, which makes them the more reliable control targets.
04
Verify
Prove it’s holding, continuously.
A target without evidence is just a slogan. Verification means showing that a system is actually holding its target throughout real operation, not only at commissioning, and not only at the single condition a spec sheet is rated for.
The principles work as a set. A dew point target that no equipment can meet, or a capable system that no one verifies, is not Humidity Performance. It is a partial answer.
It is also worth being precise about what it is not. Humidity Performance is not a new industry standard, a compliance requirement, or a seal Mojave hands out. No one “passes” or “fails” it, and it does not replace ASHRAE guidance, local code, or existing efficiency ratings. It is a shared name and a shared lens — a way of asking a question the industry has not consistently asked out loud: not just how cold does this building get, but how well does it hold humidity where it needs to be, and how do we know?
The principle behind the movement
A few things are converging to make this the right moment to name it.
Buildings are tighter and better insulated than they used to be. That is good for energy use, but it leaves moisture from people, cooking, showers, and process loads with fewer ways out. And as better envelopes and lighting shrink the sensible load, the latent load does not shrink with them, so moisture becomes a larger share of what the cooling system has to handle. Climates are trending wetter and more volatile in much of the country, pushing latent load higher even where design conditions have not been updated to reflect it. And post-2020, indoor air quality — humidity very much included — moved from a facilities afterthought to a boardroom topic, tied directly to occupant health and liability.
At the same time, humidity-sensitive facilities, such as healthcare, grocery, data centers, and hospitality, are also under growing pressure to cut energy use. Those two goals used to feel like a tradeoff: tighter humidity control meant more energy spent reheating overcooled air. Humidity Performance starts from the premise that they are not actually in conflict, once a system is designed to control moisture and temperature independently instead of using one to chase the other.
From incidental to intentional
The shift Humidity Performance describes is less about new technology and more about which questions get asked first.
Incidental Humidity Control
Humidity Performance
None of this is exotic engineering. It is a sequencing change: ask the humidity question at the same time as the temperature question, and keep asking it after the building is running, not after something has already gone wrong.
Humidity-First Climate Systems
Humidity Performance is the outcome. Humidity-First Climate Systems are the category of solutions designed to deliver it. Instead of beginning with equipment type, they begin with building performance: humidity sits at the center of climate system design, and temperature and moisture are managed according to what each building actually requires.
01
Independent control.
Sensible (temperature) and latent (moisture) loads are managed separately, rather than one being a forced side effect of the other.
02
Dew point capability across the load curve.
The system can deliver its target at partial load and in shoulder seasons, not just at the single condition a spec sheet is rated for.
03
Built-in verification.
The system produces the operating data needed to show it is holding its target over time. If a system claims Humidity Performance, it should be able to show its work.
The category is not defined by any one technology. The four principles describe what a building needs; a Humidity-First Climate System is equipment built to make those principles achievable. What qualifies a system is whether it delivers the outcome, not how it gets there.
What this means for owners, operators, engineers, and contractors
For building owners and operators
Humidity is a risk line item whether or not it is on your maintenance budget: mold liability, tenant comfort complaints, and — in grocery, healthcare, and hospitality — direct damage to product or occupant experience. Asking your design team what humidity or dew point target a system is designed to hold, what equipment can meet it, and how you’ll know it is still holding a year after commissioning is a fair and increasingly answerable question.
For engineers
Humidity Performance turns a design goal that has historically been implicit into an explicit one: a dew point target, evaluated as its own latent load calculation rather than folded into sensible cooling, then carried through equipment selection, the control sequence, and ongoing verification. It also changes what’s worth asking a manufacturer for: dew point and energy performance data across part-load and off-design conditions, not just a single peak-rated number.
For contractors
Fewer callbacks tied to comfort complaints or moisture problems, a clearer story to tell customers about what “done right” looks like, and performance data you can point to after the job closes out, particularly on jobs in humid climates or humidity-sensitive facilities, where it is often the difference between a system that gets praised and one that gets blamed.
Where Mojave fits in
Mojave did not invent humidity problems, and this series is not a claim that we have solved all of them. What we have built is the ArctiDry platform — ArctiDry DX and ArctiDry Hydro — Humidity-First Climate Systems that use liquid desiccant technology to control cooling, heating, and dehumidification independently of one another, rather than using one to chase the other. Liquid desiccant is the means; a building that holds its humidity target is the outcome.
In the field, that approach has delivered 25–50% energy savings against standard HVAC, typical payback under 18 months, and supply air dew points as low as 35°F (ArctiDry DX) and 25°F (ArctiDry Hydro), across more than 400,000 logged field hours.
We are naming and publishing this framework because we think the industry needs a shared vocabulary for the problem, not because we think we are the only ones capable of solving it. If Humidity Performance takes hold as a way of evaluating buildings, that is a win for occupants and owners regardless of whose equipment is doing the work.
Better buildings begin with Humidity Performance. A building’s climate system is only as good as its ability to manage the air it is actually responsible for, all of it, not just the part that shows up on a thermostat.