The humidity excursion you didn't see.The product you can no longer ship.
For tropical warehouses storing tobacco, dried foods, grains, paper or any hygroscopic product. Standard split air conditioning physically cannot hold 22 °C / 60% RH in Manila ambient. Karnot AHU + iSTOR + iHEAT R290 + iVOLT solar holds the warehouse at spec continuously, year-round, while taking ~89% off the electricity bill.
Why standard split AC always fails for tropical product storage.
The engineering reason your warehouse RH climbs above 65% every wet season is structural — not a fault, not bad operation, not undersizing. Split AC is the wrong machine for a latent-dominated tropical load. Four ways the existing plant fails, and what each one costs.
SHR Mismatch — sized for the wrong job
A standard split AC has a Sensible Heat Ratio of 0.70–0.85 — 70-80% of capacity goes to lowering temperature, only 20-30% to removing moisture. Your tropical warehouse needs SHR 0.40–0.50 — the load is dominated by latent moisture from infiltration, ventilation and product respiration. Specifying the wrong SHR is a fundamental engineering error, and it cannot be corrected by adding more split AC.
Short-Cycle Compressor — humidity spikes silently
The room hits 22 °C in five minutes (low sensible load). The thermostat is satisfied; the compressor cuts off. Dehumidification stops. Moisture continues to enter through loading-bay doors, ventilation, product respiration. RH spikes to 75–80% within the hour. Mould in 3–6 days; cured tobacco can be irreversibly spoiled inside one week. The damage compounds silently — it does not show up on the BMS dashboard.
Electric Reheat Workaround — illegal under ASHRAE 90.1
The lazy operator solution to humidity creep is to add an electric reheat coil: overcool the air to drop the dewpoint, then electrically reheat it. This is explicitly forbidden under ASHRAE 90.1 §6.5.2.3 (simultaneous heating and cooling) and triples the electricity bill. The only compliant path is hot-gas reheat from recovered condenser heat — which standard split AC cannot do, but a Karnot AHU + iSTOR system does by design.
Product Loss — the cost nobody puts on the spreadsheet
PHilMech (Philippine Center for Postharvest Development) documents average 12.7% storage loss on corn alone; broader agricultural loss across PH supply chains routinely reaches 50%. Tobacco operators face the same physics — once mould begins on cured leaf or finished cigarettes, the entire affected pallet is unrecoverable. Inadequate warehouse HVAC is universally cited as the primary driver.
One AHU. One reversible heat pump. Two iSTOR tanks. One iVOLT solar package.
Four products that work as one continuous system — the AHU conditions the warehouse air, the iHEAT R290 charges either iSTOR tank on demand, the iSTOR tanks buffer the AHU through every heat-pump reversal, and the iVOLT solar + Li-ION package powers the whole thing from the warehouse roof.
iHEAT R290
Reversible R290 heat pump 9.5–105 kW. Heating COP 4.14–5.59 / Cooling EER 3.51–4.16. Outdoor packaged unit, ambient −25 to +45 °C. Charges either iSTOR tank on demand.
iSTOR PCM × 2
Two phase-change thermal batteries — hot tank @ 44 °C, cold tank @ 22 °C. Patented PCM, natural fluids sourced in PH. Buffer the AHU through HP reversal — no warehouse interruption.
Karnot AHU
Fully inverter-controlled Air Handling Unit with hot coil + cold coil + ECM fan. Conditions the warehouse air directly through ductwork. Runs on humidistat for continuous RH control.
iVOLT solar + Li-ION
Roof-mounted PV array + Karnot inverter + LiFePO4 lithium-ion battery. Sized to power the entire AHU + iSTOR + iHEAT system through any grid event. Eliminates diesel-generator OPEX.
One zone. ~89% off the bill. ~2.9-year payback.
First-principles ASHRAE Heat Balance Method calculation on a 200 m² tobacco-product warehouse zone at 22 °C / 60% RH spec. Existing setup: 5 × 3 HP + 1 × 2 HP split AC running 24/7. Tariff: ₱14/kWh including 3-phase service premium. Existing annual electricity cost: ~₱629,000. Replaced with Karnot iHEAT 18.5 kW R290 + iSTOR PCM thermal storage + dual-coil AHU + 15 kWp iVOLT roof solar: ~₱65,000 annual cost. Net annual saving: ~₱564,000 per zone. CO₂ avoided: ~28 tonnes per year per zone. Customer name withheld. Real numbers from a free site audit on your specific warehouse.
Capital purchase. ~2.9-year payback per zone.
Karnot equipment is sold outright with a 3-year warranty on the heat-pump core. Per-zone payback figures are from a worked first-principles 200 m² warehouse case study. Energy-efficiency capex may qualify for BOI incentives under RA 11285 — Karnot supports the registration paperwork; the final package is confirmed by BOI on a case-by-case basis.
From the day it's commissioned, the bill drops.
Energy Efficiency & Conservation Act incentives.
Most warehouse climate retrofits qualify. Karnot supplies the BOI registration paperwork as part of the project handover.
- RA 11285 framework — codifies energy efficiency as a public-policy priority
- RA 11285 classification support — Type 1 / Type 2 designated establishment
- BOI registration — Karnot supports application paperwork as standard project scope
- Final incentive package — confirmed by BOI based on project profile and Strategic Investment Priority Plan
- Verify with your tax adviser before commitment — incentives are not guaranteed
Download the Karnot Warehouse Climate System brief
The full sales deck and the four-page flyer — both ready to share with your facilities team, your CFO or your board.
Engineering Tools for Warehouse Projects
Free calculators to size your warehouse climate-control system.
Behind your meter. Sized to your load. Not to the net-metering cap.
Most Filipino businesses have been sold solar that covers only 20% of consumption. That is not a regulatory cap — it is what solar gives you without storage. The government's April 2026 circular lifted net metering to 1 MW for commercial sites; and if your solar only feeds your own site, never exporting to the grid (utilities call this Zero Export), there is no cap at all. The missing piece is storage that actually matches your load — which on most industrial and commercial sites is mostly thermal, not electrical.
1 · Karnot iVOLT solar & LiFePO₄
Solar inverters and LiFePO₄ batteries sized to the roof you actually have. LiFePO₄ chemistry chosen for tropical safety — no thermal runaway, 6,000+ cycle life. Configured for Zero Export so the only cap is your own daytime demand.
2 · Karnot iHEAT & iCOOL
R290 heat pumps for hot water, process heat, and reversible air conditioning; CO₂ for refrigeration. The heat pump is the largest customer of the iVOLT battery — absorbing solar before it gets exported and banking it as heating or cooling capacity instead.
3 · Thermal batteries that aren't lithium
iSTOR phase-change batteries for hot water and process heat, Permafrost for chilled water and cold-chain. 5–10× cheaper per kWh than lithium for thermal loads — with the Karnot FLX coconut-based PCM in development, sourced from the next province over.
We do not sell solar. We do not sell heat pumps. We do not sell batteries. We sell the integrated Philippine solution that lets all three actually work together — behind your meter, sized to your real load, with thermal storage that matches what your site actually consumes.
You've been told 100 kWp is the cap. It isn't. And it hasn't been since April.
Every solar quote a Philippine commercial customer received before mid-2026 was anchored to the old 100 kWp net-metering cap. Two regulatory routes have opened — one explicitly, one that was always there.
Three ways to spend a midday solar kWh. Only one keeps the value.
Once your rooftop solar is large enough to outrun midday demand, every excess kWh becomes a disposal problem. There are three options. Two of them lose you money.
Frequently Asked Questions
Why does standard split air conditioning fail in tropical warehouses?
A standard split AC has a Sensible Heat Ratio (SHR) of 0.70–0.85 — designed to remove sensible heat. A tropical warehouse load is dominated by latent moisture (SHR around 0.40–0.50). The split hits its temperature setpoint in minutes, the compressor cuts off, and humidity continues climbing through loading-bay door cycles, ventilation infiltration and product respiration. RH spikes to 75–80%, mould forms in 3–6 days, and stored hygroscopic product is irreversibly damaged.
What is the payback period for a Karnot installation?
Sub-12-month paybacks are realistic on integrated retrofits combining solar (Karnot iVOLT), heat pumps (iHEAT R290 or iCOOL CO₂), and thermal storage (iSTOR or Permafrost) at sites paying full commercial grid tariff. Standalone retrofits pay back more conservatively — iMESH adiabatic chiller upgrade typically under 12 months, DHW-only retrofit replacing LPG or diesel in 18–24 months. Most installations qualify for BOI Pioneer status and Income Tax Holiday under RA 11285, which shortens payback further. Karnot files the BOI registration paperwork as part of project scope.
Does this help our SEC PFRS S2 sustainability disclosure?
Yes — directly. Replacing an R-32 / R-410A split-AC fleet (GWP 675 / 2,088) with Karnot iHEAT R290 (GWP 3) cuts the refrigerant Scope 1 line by >99%. Pairing iVOLT zero-export solar with the iSTOR thermal batteries cuts Scope 2 grid electricity by ~89%. Both reductions land on the same SEC PFRS S2 disclosure your CFO submits — and the green-loan filing pack Karnot prepares includes the figures formatted for that disclosure.
What happens during a power outage?
iSTOR phase-change thermal batteries store up to 80kWh of hot water energy, providing hours of backup without electricity. When paired with generator backup, the heat pump restarts automatically and the thermal store bridges the transition period seamlessly.
Why am I being told my solar can only cover 20% of my electricity bill?
That 20% figure is not a regulatory cap — it is the daytime self-consumption ceiling that solar gives you without storage. Two routes raise it: (1) the government's April 2026 circular lifted the net metering cap to 1 MW for commercial sites, and (2) if your solar only feeds your own site, never exporting to the grid (utilities call this Zero Export), there is no capacity cap at all. The binding constraint is your ability to absorb daytime generation — which is exactly what Karnot heat pumps plus thermal storage solve, by banking solar as heating, cooling, and hot water for night-time dispatch.
How does Karnot help with demand charges?
Commercial electricity bills include a demand charge based on the highest 15-minute kVA peak in the billing period. Heat pumps charging a Permafrost or iSTOR thermal battery overnight or during off-peak hours dispatch hot water and chilled water during the daytime peak, so the heat-pump compressor can be sized smaller and run at lower nameplate during the peak window. This shaves the 15-minute peak — often the single largest controllable line on a Philippine commercial electricity bill.
How is Karnot different from MSpectrum, Solaric, or other Philippine solar installers?
They sell solar panels. Karnot sells the integrated solution that lets solar actually work for a commercial site: solar plus heat pump plus thermal battery, sized to your real load profile and configured behind the meter. We do not install net-metering systems capped at 20% offset. We engineer Zero Export installations sized to whatever your roof and load can carry. The result is typically 60–80% bill reduction instead of the 4–20% that solar-only installs deliver on a 24/7 commercial load.
Ready to Hold Your Warehouse at 22 °C / 60% RH Year-Round?
Book a free site survey. Our engineers will model your warehouse load using the ASHRAE Heat Balance Method, size the AHU + iSTOR + iHEAT + iVOLT package, and show you the exact payback.