HP v3
Energy hidden
in a moment
of change.
Phase change materials store and release enormous amounts of thermal energy the instant they melt or freeze — holding temperature steady while quietly doing the work. It's one of nature's most powerful and underutilized phenomena.
Two kinds of heat.
One is vastly more powerful.
Understanding why PCM works starts with a distinction most people never learn: the difference between sensible heat and latent heat.
Why temperature isn't the whole story
When you heat water on a stove, its temperature rises steadily — that's sensible heat. Every BTU you add shows up as a measurable temperature increase. It's predictable, linear, and ultimately limited in how much energy you can pack into a given volume.
But when water reaches 212°F and begins to boil, something remarkable happens: you can pour in enormous amounts of energy and the temperature stops rising entirely. That energy isn't disappearing — it's being absorbed into the physical process of breaking molecular bonds. This is latent heat.
"It takes as much energy to melt one pound of paraffin as it does to heat a pound of water by 100°F — yet during the melt, the paraffin's temperature doesn't change at all."
Phase change materials are engineered to exploit this phenomenon at precisely useful temperatures — from –40°F for deep-freeze cold storage, through the 55–130°F sweet spot for hot water and refrigeration, up to 400°F+ for industrial heat recovery.
The result is a thermal battery that charges and discharges at a fixed, controllable temperature — with dramatically higher energy density than any water tank or ice block of equivalent size.
| PCM Material | Melt Point | Latent Heat | Application |
|---|---|---|---|
| Water / Ice | 32°F | 144 BTU/lb | Freezer buffer |
| Paraffin C18 | 86°F | 100 BTU/lb | Hot water boost |
| Paraffin C22 | 124°F | 98 BTU/lb | High-temp hot water |
| Salt hydrate (CaCl₂) | 82°F | 75 BTU/lb | Refrigeration buffer |
| Erythritol | 239°F | 130 BTU/lb | Industrial recovery |
Charge. Hold. Release.
Every PCM application follows the same elegant three-phase cycle — storing energy when it's plentiful, holding it without significant loss, and delivering it precisely when needed.
Charging — the PCM melts
Heat flows into the PCM from a heater, waste heat source, or off-peak electricity. As the material reaches its melt point, it absorbs massive amounts of energy while its temperature holds perfectly steady — transitioning from solid to liquid and locking energy into its molecular structure.
Solid → LiquidStorage — energy held in reserve
Once melted, the PCM retains its stored latent energy without significant loss. Unlike a hot water tank that bleeds heat continuously to its surroundings, a well-insulated PCM vessel holds its thermal charge for hours — or days — ready to deploy the moment demand arrives.
Liquid — ready to dischargeDischarge — delivered on demand
When a refrigerator coil, water circuit, or air handler draws heat from the PCM, it re-solidifies — releasing all of its stored latent heat at the exact same temperature it absorbed it. The output is perfectly steady from the first moment to the last molecule frozen.
Liquid → SolidFour applications.
One elegant principle.
The same physics that makes an ice cube cool your drink can protect a walk-in freezer through a power outage, multiply your home's hot water, and recover megawatts of waste heat from an industrial process.
Freezer thermal buffer
PCM panels inside commercial or residential freezers absorb excess cooling during off-peak hours and release it during compressor off-cycles, door openings, or power outages. Temperature stays locked at the PCM's freeze point — protecting product and slashing compressor runtime.
Refrigerator energy reduction
A PCM shelf inside a refrigerator acts as a thermal flywheel — absorbing energy when the compressor runs and slowly releasing it when the compressor cycles off. The fridge holds temperature with far less compressor runtime, cutting energy use and wear on the system.
Hot water capacity boost
A PCM thermal buffer paired with any water heater — gas, electric, or tankless — multiplies available hot water without adding a second unit. The PCM charges slowly during quiet periods and discharges instantly during peak demand, so a small heater delivers the output of a much larger one.
Industrial waste heat recovery
Factories, powder coating lines, bakeries, and data centers shed enormous amounts of thermal energy. A PCM vessel captures this heat at the source, stores it isothermally, and delivers it hours later to pre-heat process water, warm facility air, or supply industrial hot water — energy that would otherwise go up a flue.
The vocabulary of
thermal storage.
You don't need a physics degree to work with PCM — but a solid grasp of these concepts will help you evaluate systems, ask better questions, and make confident decisions as you explore our products.
Each concept below builds on the last. Read from the top, or jump to whatever you need.
Our product pages apply each of these principles to real specifications — capacity, recharge time, and peak output — for your specific use case.
Explore the products →What is latent heat, exactly?
What does "isothermal" mean in practice?
How is a PCM different from a hot water tank?
What is "peak demand" and why does it matter?
Are paraffin PCMs safe around food and potable water?
How do you choose the right melt point?
You understand the science.
Now see it in action.
CoreTherma applies these principles in engineered products built for real-world installation — from residential hot water boosters to commercial cold chain buffers to industrial heat recovery systems.