Low‑Pressure Solar Geyser Specs | The Sun Pays

Low-Pressure Solar Geyser Technical Guide

If you want to save money on your electricity bill, start with a solar geyser. This guide will help you decide whether a low-pressure solar geyser suits your needs.

💧 Difference Between Low and High-Pressure Geysers

Municipal water supply pressure typically ranges from 1 bar to 5 bar depending on location and time of day.

High-Pressure Geysers

Connect directly to municipal water without a pressure-reducing valve
Can be integrated into existing plumbing systems
Delivers hot water at similar pressure to cold water
Ideal for high-flow fixtures like mixer taps and showers

Low-Pressure Geysers

Open to atmosphere — hot water pressure equals the static head (mounting height)
Can work with municipal water if a pressure-reducing valve is used on the cold side
The auxiliary tank helps balance hot water pressure in the system

🔆 Low-Pressure Solar Geyser Design

The geyser is mounted on top of your roof and uses evacuated vacuum glass tubes to heat water via direct sunlight. These tubes connect into a tank, with an auxiliary tank mounted above it.

📏 Sizing Your Geyser

Standard sizes: 100L, 150L, 200L
Estimate at least 50L per person in the household
Two geysers can be connected in series for higher capacity

🧪 Available Models

Model	100L	150L	200L
Qty. of Tubes	10	15	20
Tube Size	58 x 1800 x 2 mm
Exterior Tank Material	0.35mm Stainless Steel Sheet
Interior Tank Material	0.35mm SUS304 Stainless Steel
Outer Tank Diameter	470 mm
Insulation	55mm Polyurethane Foam
Stand	Flat/pitched roof stand (1.5mm galvanized and painted)

📦 What’s Included in the Kit

100L–200L stainless steel tank with SUS304 inner and outer casing
Flat or pitched roof mounting stand
10–20 x 2mm vacuum glass tubes (hail-resistant, 58mm)
Stainless steel auxiliary tank

🔌 Optional Electrical Backup

All geyser models can accommodate a standard 32mm screw-in South African electric element with a dry pocket for thermostat or programmable controller.

Programmable Controller Features:

Displays real-time tank water temperature
Three programmable heating cycles with target temperatures
Default schedule: if below 54°C at 4–5am or 5–10pm, it heats to 60°C
Manual boost button to heat to target temperature
Battery backup to preserve settings during power outages

✅ Why Choose a Low-Pressure System?

Very cost-effective and simple to install
No moving parts — longer life expectancy
Low maintenance and highly reliable
Well-suited for gravity-fed and rural applications

Note: Consider plumbing diameter (15mm vs 22mm) for optimal water flow. One-lever mixer taps can restrict flow; two-knob taps usually perform better.