Key Specifications at a Glance
Full DC inverter pool temperature control systems covering residential plunge pools to large commercial facilities. Heating and cooling in one unit.
How Pool Temperature Control Works
A pool temperature control system moves thermal energy between the air and your pool water. In heating mode, it extracts warmth from the air and delivers it to the pool. In cooling mode, it reverses the cycle to remove excess heat — delivering 5-7 times more thermal energy transfer than the electricity it consumes.
1. Absorb Heat from Air
The DC fan draws ambient air across the evaporator coil, where R32 refrigerant absorbs thermal energy and evaporates at low temperature.
2. Compress and Amplify
The Panasonic DC inverter compressor raises the refrigerant temperature and pressure, concentrating the harvested energy into usable high-grade heat.
3. Transfer to Pool Water
Hot refrigerant passes through the titanium tube-in-shell heat exchanger, transferring heat directly to the circulating pool water safely and efficiently.
Advanced Pool Temperature Control Technology
Every iSPA unit combines premium components and intelligent controls to deliver reliable, efficient pool temperature control — heating and cooling — in any climate.
R32 Refrigerant System
- Low GWP of 67568% lower global warming potential than R410A (GWP 2088). More thermodynamically efficient per kilogram of charge.
- Danfoss Electronic Expansion ValvePrecision superheat control across all operating conditions. Faster response than mechanical TXVs for optimal efficiency.
- SANHUA 4-Way Reversing ValveSeamlessly switches between heating and cooling modes. Heat your pool in winter, cool it in summer.
DC Inverter Components
- Panasonic DC Inverter CompressorVariable-speed operation matches output to demand. No hard starts, reduced wear, lower noise, and peak efficiency at partial loads.
- Nidec DC Fan MotorBrushless DC motor with stepless speed control. Whisper-quiet operation with precise airflow management.
- Titanium Tube-in-Shell ExchangerMarine-grade titanium resists saltwater, chlorine, and bromine. No corrosion, no contamination, maximum heat transfer.
Touchscreen Controller
Intuitive colour touchscreen for temperature setting, scheduling, mode selection, and diagnostics. No complex menus.
Wi-Fi Ready
Connect to your home network for remote monitoring and control via smartphone app. Check pool temperature from anywhere.
Spray-Coated Steel Body
Durable white steel cabinet with anti-corrosion spray coating. Designed to withstand outdoor pool environments year-round.
Why Choose iSPA Over Gas or Electric?
Traditional pool heating methods are expensive, inefficient, and increasingly obsolete. The iSPA delivers superior results at a fraction of the running cost.
Gas / Electric Pool Heaters
- COP of 0.8-1.0 -- most energy wasted as exhaust
- High monthly gas or electricity bills
- Combustion produces CO and NOx emissions
- Gas supply infrastructure required
- Short lifespan of heating elements and burners
- No cooling capability — pools overheat in tropical climates
Karnot iSPA Temperature Control
- COP up to 7.52 -- 5-7x more efficient
- Up to 85% lower running costs
- Zero on-site emissions or combustion
- Only requires a standard electrical connection
- Long-life titanium exchanger and DC compressor
- Both heating and cooling modes built in
COP up to 7.52
Over 7 kWh of pool temperature control for every 1 kWh of electricity. Under optimal conditions, COP can reach 14.05.
Heat and Cool
Heating mode: 18-35 °C water output. Cooling mode: 15-32 °C. Perfect for tropical pools that overheat, as well as extending swim seasons in cooler climates.
Quiet Operation
Noise levels from just 37 dB(A) on smaller models. DC inverter runs at low speed when demand is light.
Wide Ambient Range
Operates from -15 °C to 45 °C ambient. Reliable performance in tropical, temperate, and cold climates.
Saltwater Compatible
Titanium tube-in-shell exchanger is immune to saltwater, chlorine, and bromine corrosion.
Low Environmental Impact
R32 refrigerant with GWP 675 -- 68% lower than R410A. Efficient operation further reduces carbon footprint.
Ideal Applications
The iSPA range covers every pool temperature control need — heating pools in cooler weather and cooling them when tropical sun pushes water temperatures too high — from backyard pools to large commercial facilities.
Residential Pools
Maintain the perfect pool temperature year-round — heat when it's cold, cool when tropical sun overheats your water. Quiet operation and compact design suit any backyard.
Commercial Pools
Gyms, sports centres, and swim schools. Reliable heating for high-usage pools with demanding temperature requirements.
Hotel and Resort Pools
Precise temperature control for guests 365 days a year — cooling overheated pools in summer, heating in winter. Silent operation preserves the premium guest experience.
Water Parks
Large-capacity 3-phase models (28-39 kW) efficiently heat large pools and lazy rivers. Cascade multiple units for any size.
Spas and Hot Tubs
Precise temperature control from 18-35 °C. Maintain therapeutic water temperatures efficiently without electric elements.
Complete iSPA Product Range
11 models from 6.5 kW to 39 kW. Single-phase (220V) and three-phase (380V) options for residential and commercial installations.
Single Phase (220V)
Three Phase (380V)
All prices: Contact for Quotation | Multiple units can be cascaded for pools larger than 100 m³
Pool Temperature Control Calculator
Find the right iSPA model for your pool. Enter your pool details below and we will recommend the ideal unit for heating and cooling.
Find Your Ideal iSPA Model
Your Recommended iSPA Model
UK: £0.17/kWh electricity
Need an Accurate Quote?
This calculator provides estimates based on typical conditions. For a precise sizing analysis including local climate data, pool construction, and wind exposure, request a complimentary pool temperature control assessment.
Ready to Control Your Pool Temperature?
Request your free pool temperature control assessment and receive a detailed recommendation for heating and cooling your installation.
Request Free AssessmentFrequently Asked Questions
What COP do Karnot iSPA pool temperature control systems achieve?
Karnot iSPA pool temperature control systems achieve COP ratings from 5.98 to 7.52 at standard test conditions (A27/W27). Under optimal conditions, COP can reach up to 14.05. This means you get 6-7 kWh of pool heating for every 1 kWh of electricity consumed.
Can the iSPA cool my pool as well as heat it?
Yes. All Karnot iSPA models feature both heating and cooling modes. In heating mode, water temperature ranges from 18 to 35 degrees C. In cooling mode, water temperature ranges from 15 to 32 degrees C. A SANHUA 4-way valve automatically reverses the refrigerant cycle.
Is the iSPA safe for saltwater pools?
Yes. All Karnot iSPA models use a titanium tube-in-shell heat exchanger that is fully resistant to saltwater, chlorine, and bromine corrosion. Titanium is the gold standard for pool heat exchanger longevity.
What size pool can the iSPA heat?
The iSPA range covers pools from 15 cubic metres up to 100 cubic metres and beyond. The smallest model (iSPA 6R at 6.5 kW) suits pools of 15-20 cubic metres, while the largest models (iSPA 39N at 39 kW) handle pools of 50-100 cubic metres. Multiple units can be cascaded for larger pools.
What refrigerant does the iSPA use?
The iSPA uses R32 refrigerant, which has a Global Warming Potential (GWP) of 675, roughly 68% lower than the older R410A refrigerant (GWP 2088) that it replaces. R32 is more energy efficient and requires less charge per unit of cooling capacity.
Can the iSPA operate in cold weather?
Yes. The Karnot iSPA operates in ambient temperatures from -15 degrees C to 45 degrees C. The full DC inverter system with Panasonic compressor and Danfoss electronic expansion valve automatically adjusts to maintain performance across this wide range.