Barefoot, even in August.
CoolStone hides a hydronic system beneath your terrace stone — cooling it enough to walk barefoot in high summer, and carrying that free solar warmth into your pool to extend the season. Nothing on show, nothing to hear. It complements a heat pump; it will not heat the pool in winter.
Photography is illustrative. No CoolStone system is installed in any image on this page.
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- Stone slabs
- Bedding layer with CoolStone loops
- Insulation (XPS)
- Ground
- Ti heat exchanger — the terrace circuit ends here; a separate circuit feeds the pool
An invisible hydronic terrace that cools the stone and warms the pool.
Water channels hidden in the bedding layer beneath your paving draw the sun's heat out of the stone and carry it into the pool — using only the energy the terrace already collects and one small circulation pump. Nothing sits on the terrace, there is no plant beside the pool, and there is nothing to hear.
What it adds to the house — and to the summer.
Cool stone underfoot
Paving that would blister bare feet at three in the afternoon becomes walkable — morning-warm, not cold — right through August.
A longer season in the water
Free solar warmth, carried from the terrace into the pool, extends comfortable swimming at both ends of the summer.
Invisible and silent
No panels on the roof, no box beside the pool, nothing to hear. Specified at design stage, the system disappears into the architecture.
Sustainable comfort
Warmth harvested from stone the sun has already heated, moved by one small pump — no combustion, no compressor. A heated pool without the climate guilt.
Works with your pool
It sits alongside your existing pool and water-treatment systems, including chemical-free natural water. It adds a layer; it replaces nothing.
Measured and monitored
An owned control layer watches performance, leaks and safety, and reports what the system is actually doing. Effortless, white-glove ownership.
Every system has limits. We publish ours first.
It will not heat your pool in winter
December–February sun is too weak. Winter swimming needs a heat pump — CoolStone reduces its workload in the shoulder months, it doesn't replace it.
It needs an automatic pool cover
Without an automatic cover, evaporation carries the pool warmth away almost as fast as we add it, and the pool benefit largely collapses. If you don't have one, we quote the cover first — even though it costs us the sale.
Your terrace won't feel cold
In August the stone drops from hotplate (55–65 °C) to morning-warm (40–48 °C). Walkable, not chilled.
Shaded terraces don't qualify
Performance needs genuine sun. It depends on orientation, shading, stone colour and wind — we assess every site first, and we'll tell you honestly if yours won't perform.
These are estimates — for now
Every figure on this page is an engineering estimate. Our founding installations are fully instrumented and we publish the measured results, good or bad — real data, not brochure numbers.
Reality, not hype. Estimates until our founding installations prove them.
Worked example: 80 m³ pool (~36 m² of water), 100 m² of active terrace, Algarve sun, automatic cover closed at night.
With automatic cover
- +4–7 °C warmer pool
- 6–10 weeks longer season
- ~90% of collected heat retained overnight
Without a cover
- +1–3 °C only — evaporation dumps 100–200 kWh/day
- 2–3 weeks of season extension at best
- Deck cooling unchanged — the terrace doesn't care
Why we tell you this: without a cover you would be filling a leaking bucket, and we would rather lose the sale than oversell the system. If you don't have an automatic cover, we'll quote one first.
Your terrace is already a solar collector. We just connect it.
Portuguese terrace stone reaches 55–65 °C in summer sun — a huge store of free energy that currently does nothing but burn feet. CoolStone circulates fluid through channels hidden in the bedding layer, built entirely from proven, CE-certified European hydronic components. It complements a heat pump rather than replacing it: the heat pump gives temperature on demand, CoolStone does the free, invisible, sunny-day work.
Under the stone
High-contact hydronic loops draw heat out of the terrace, cooling the surface by 10–15 °C at peak sun.
Into the pool
A titanium heat exchanger passes the captured energy into your pool water — 150–220 kWh on a summer day, for the running cost of one small pump.
August night cooling
When the pool overheats past 30 °C in high summer, the same loops run at night — radiating pool heat to the sky and bringing the water back to refreshing.
A heated pool, without the climate guilt.
A pool that is warm from spring to autumn usually means a bill and a carbon cost. CoolStone changes where that warmth comes from — the sun the stone was already absorbing — and asks only a small pump to move it.
No combustion, no compressor
The only energy in is a small circulation pump. There is no gas burning and no refrigerant cycle running to make the pool warm.
The sun the stone already collects
The terrace is a solar collector heating up in the sun whether you use it or not. CoolStone simply puts that energy to work instead of letting it burn feet.
Toward a zero-carbon pool
Alongside a heat pump, CoolStone does the sunny-day work, so on bright days the pool trends toward zero-carbon — the reliable baseload stays for the days the sun can't cover.
A private climate consultancy, not a product off a shelf.
CoolStone is a professional consultancy — insured and specified like any serious building-services engineer, not a free quote. Four stages, working alongside the people already building your home.
Private assessment
A paid, professional site consultation with no obligation to proceed — orientation, stone, shading, pool and cover — ending in an honest verdict on whether your terrace will perform. If it won't, we tell you.
Design
We design the hidden circuit into your terrace build-up and pool plant, working with your architect and pool builder so nothing shows and nothing clashes.
Integration
Installation in the bedding layer as the terrace is built or renovated, from CE-certified European components, tied into your existing pool and water systems.
Monitoring
The owned control layer runs the system, watches for leaks, and reports performance — so ownership stays effortless, measured and safe.
Specify comfort that leaves no trace.
We work as an engineering partner to the design team. The system lives in the bedding layer, so it never touches your material palette, your layout or your joint pattern — and we coordinate to your build sequence.
Nothing to design around
No roof array, no visible plant, no compromise to the paving. It is specified at design stage and then disappears.
Same stone, inside and out
Because the system sits beneath the surface, your material palette is untouched — the terrace reads exactly as you drew it.
We work to your programme
We coordinate with your build sequence and your pool builder, and integrate with whatever pool and water systems the client already has.
A limited first cohort. At cost. Measured and shared.
We are opening a small founding cohort — the first flagship CoolStone installations in Portugal, ideally where a terrace is being built or renovated. Founding clients receive the system at cost with full engineering support, and their results — measured and shared — become the proof the company stands on.
At cost
Components and engineering at zero margin, with the founding price locked before you commit.
Fully instrumented
Deck, pool and energy sensors log all season through the monitoring dashboard. You see everything we see.
First of its kind
A limited founding cohort, not an open product — your installation among the very first, with results shared as they come in.
