High-Temperature Pool Chiller: Cooling a 3,000 L Tank in the Gulf Heat

In the Gulf summer, an unshaded water tank is effectively a solar heater. A 3,000 L storage tank or swimming pool sitting in direct sun can climb to 50–60 °C — far above the 25–30 °C a swimmer expects, and well past the temperature at which potable water should be stored. A Saudi customer recently asked Delin to engineer a chiller for exactly this duty. This case study walks through the requirements, the heat-load math, and the design choices that let a standard industrial chiller work in the desert.

The Challenge: A Tank That Behaves Like a Solar Collector

Requirement	Value
Tank volume	3,000 L
Inlet water temperature	up to 50–60 °C
Target temperature	25–30 °C
Power supply	380 V / 50 Hz / 3-phase
Wetted materials	Pure titanium (all water-contact parts)
Water quality	Potable / drinking-water compatible
Installation	Outdoor, Saudi Arabia
Design	Integrated unit, pure-titanium circulation core

Why This Is Not Standard Chiller Duty

• High inlet temperature. Standard process chillers are rated for 7–12 °C chilled water. Here the evaporator must accept water entering at 50–60 °C, so the heat exchanger and control range are sized for high-inlet duty rather than taken from a data-sheet nameplate.
• 50 °C ambient. A condenser sized for a 35 °C design day loses capacity and risks high-pressure trips at 50 °C. The unit therefore carries a high-ambient condenser package — oversized coil and fan set plus high-pressure controls.
• Aggressive water. Gulf supply is often desalinated, chlorinated, or naturally high in chlorides. A copper coil would corrode and contaminate the stream; titanium does not.
• Outdoor enclosure. Weatherproof, sealed construction against sun, dust, and seasonal humidity.

The Heat-Load Math

Cooling 3,000 L of water from 60 °C to 30 °C is a 30 K temperature drop. The energy to remove:

Q = m × c × ΔT = 3,000 kg × 4.186 kJ/kg·K × 30 K ≈ 105 kWh

Step	Value
Water mass	3,000 kg
Temperature drop ΔT	30 K
Energy to remove	≈ 105 kWh (≈ 377,000 kJ)
Chiller nominal capacity	14.5 kW
Ideal cooling time, no losses	≈ 7.2 h
Effective capacity at 50 °C ambient	≈ 11–12 kW (≈ 75–85 % of nominal)
Realistic cooling time	≈ 9 hours

The gap between the ideal 7.2 h and the realistic ≈ 9 h is the desert itself: condenser derating at 50 °C ambient plus continuous solar gain into the tank and piping. A quoted "9 hours" is honest engineering, not an optimistic figure from the brochure.

Selected Model: DL-E050R2F-AA

Parameter	Value
Model	DL-E050R2F-AA
Cooling capacity	14.5 kW (5 HP)
Power input	4.35 kW · 380 V / 50 Hz / 3-phase
Heat exchanger	Pure Grade 2 titanium
Water-contact wetted path	Titanium only (plus food-grade gaskets)
Refrigerant	R410A (closed loop — never contacts water)
Design	Integrated, outdoor-rated

The 5 HP / 14.5 kW rating matches the customer's power configuration, and its capacity aligns with the 9-hour duty. An integrated titanium circulation core keeps the wetted path short, serviceable, and free of corrosion joints.

Why Grade 2 Titanium Is Non-Negotiable Here

• Corrosion at temperature. Corrosion rates roughly double with every 10 °C rise in water temperature. A copper or 316 stainless part that is "fine" at 25 °C becomes a maintenance liability at 60 °C — especially in chloride-laden water.
• Potable-water safety. Titanium is biologically inert and does not leach into the stream, so the wetted loop is compatible with drinking-water contact. Copper and many alloys are not.
• Long service life in the Gulf. Titanium is unaffected by the chlorinated, desalinated, or blended supply common in the region — no scale build-up, no pitting, no taste or odour.

Practical Notes for Tank-Chiller Installations

• Batch vs. recirculation. A 3,000 L tank is typically cooled by circulating tank water through the chiller until setpoint is reached. Size the circuit so the pump can turn over the tank volume in roughly an hour for even temperature throughout.
• Shade and insulate. Putting even part of the tank surface in shade cuts daytime heat gain noticeably and shortens cooling time.
• Clean-air placement. Keep the condenser clear of walls and heat sources. In 50 °C air, every degree of unobstructed airflow counts.
• Cool overnight. A simple timer or temperature controller lets the unit cool at night, when ambient is lower and the chiller runs more efficiently.

Summary

Customer need	Delin answer
3,000 L tank, 50–60 °C inlet → 25–30 °C	DL-E050R2F-AA, 14.5 kW / 5 HP
Potable-water compatible wetted path	Pure Grade 2 titanium + food-grade seals
Outdoor Gulf installation	High-ambient condenser package, IP-rated enclosure
Cooling time	≈ 9 hours, backed by the heat-load calculation
OEM sample	Available, built to customer specification

A "high-temperature pool chiller" for the Gulf market is less a special product than a standard industrial chiller correctly specified: high-inlet evaporator, high-ambient condenser, titanium everywhere water touches, and a sizing calculation the customer can check by hand. That is exactly how Delin builds it.