GUIDE to HOT WATER STORAGE TANKS
TWIN COIL WATER STORAGE TANK ARE INDIRECT FEED
ie; the fluid inside coils never mixes with the water in the storage tank.
OPTIONAL HOT WATER STORAGE TANK
Tank-in-Tank technology represents a significant advance in the science of hot water production. A greater heat transfer surface means the Tank-in-Tank units recover much faster than any other type of hot water storage cylinder - keeping boiler cycling to a minimum, and ultimately giving improved fuel efficiency with outstanding hot water delivery.
The design of the inner cylinder not only ensures scale-free operation but also avoids the sediment problems that plague conventional cylinders. Even after years of use the inner stainless steel tank would be as clean as the day it was installed.
Available are hot water storage tanks made of;
copper or stainless steel.
Given the cost, each type comes with benefits.
TANK-in-TANK Advantages Over Twin Coil Tank
∗ Increased heating surface for rapid domestic hot water recovery
∗ Large primary volume allows for greater thermal store
∗ Can be used as a low loss header for heating circuit
∗ Smaller compact tank with increased performance
∗ Immersion heater in primary circuit
∗ More heat sources absorbed into the tank
∗ Flexible design options for specifiers and installer
The combination of solar hot water heating and using the back-up heat from a wood stove chimney to heat water can enable a hot water system to work all year round in cooler climates without the supplemental heat requirement of a solar hot water system being met with fossil fuels or electricity.
Hygiene
The storage tank of a Tank-in-Tank system is made of stainless steel. Stainless steel is sanitary (it is generally used in hospitals and in the pharmaceutical and food and beverage industries), requires no maintenance whatsoever (it does not require anode protection), and enables the use of high storage temperatures.
In addition, the storage tank of a "Tank-in-Tank" system prevents the formation of warm pockets because even the base of the inner tank is a heat exchanger that remains at the temperature of the boiler (typically from 60 to 80°C): thus, any "Tank-in-Tank" water heater operating at 60°C ensures that the hot water remains free of legionellae and safe for the consumer.
GUIDE to SOLAR CONTROLLERS and TEMPERATURE SENSORS
The Solar Controller is the brain of our solar system.
The controller monitors the temperature in the solar panel located on the roof and also the temperature in the water storage tank. As the sun rises the solar panel will warm, as soon as the controller senses that the solar panel is 6 degrees higher in temperature than the water in the hot water storage tank, the solar panel will start the solar circulation pump, which transfers the heat to the hot water storage tank.
The differential controller tells the pump when to turn on and off. The controller, via sensors connected to the solar panel (on the roof) and the storage tank, determines whether the solar panel outlet is sufficiently warmer than the bottom of the storage tank to turn the circulating pump on.
The sensors are located at the collector outlet, and at the bottom of the storage tank. These sensors are thermistors that change their resistance with temperature. The differential control compares the resistances of the two sensors. It turns the pump on when the solar panels are warmer (usually 20°F) than the bottom of the water storage tank to collect useful heat. The controller usually shuts the pump down when the temperature difference is 3 to 50F.
Solar controllers can also store and output data to a computer or digital display, also have a freeze prevention feature which pulses the pump if at regular intervals when the solar panel temperature drops below 10c.
