Passive Open Loop - ICS Batch

An ICS system consists of an enclosed storage tank that acts as a large collector in which cold water is supplied at the bottom of the tank.

This system embraces the principals of stratification to collect and use hot water at the top of the tank and replaces used hot water with cooler water at the bottom.

Typically in these systems it is very rare that the ICS tank would freeze and suffer damage, however exposed piping are subject to freeze damage, and a simple Vernatherm Freeze Protection Valve could be installed as shown on the right to protect exposed piping.

The freeze protection valve must be placed on the exit of the tank so that in the event of freeze the valve would open and allow warm water to fill the pipes. The cold water line 'IN" will supply pressure to move the water through the system, out of the tank, and protect the piping.

Open Loop Direct System

An open loop direct system directly heats the water that will be used, and is circulated with the aid of a pump.

In this diagram cold water is fed directly into the system to the bottom of the solar collector, and uses the principal of stratification. When the cold water at the bottom heats up it will rise to the top which is then collected into the storage tank.

A controller with two temperature sensors cycles on and off when needed to keep water at the pre-set temperature selected by the owner.

If the power were to go out, the system is vulnerable to freeze damage in cold conditions. Use a Vernatherm Freeze Protection Valve at the bottom of the collector to prevent any damage from occurring. This valve requires no power source and operates on temperature drop. When this valve opens after it has detected near freezing conditions it will close again after purging cold water from the collector; ensuring warm water prevents freezing.

Open Loop Thermosyphon System

An open loop thermosyphon system stores it's hot water in a collection take that typically is mounted above the solar collector. Utilizing the concept of stratification that hot water rises, hot water is siphoned from the top of the collection tank down into an auxiliary water heater tank and eventually out to the user.

This open loop system uses residential water pressure, and the demand from the end user; when water is used, cold water is replaced within the system, and heated.

This system can freeze in cold climates and a simple Vernatherm freeze protection valve can be installed as shown to prevent this from happening.

Closed Loop Drain Back System

A pump assisted (Active) system in which fluid in a closed loop fashion is pumped through a collector which transfers the solar thermal energy it collects to a heat exchanger. This heat exchanger heats cool water within the tank for residential hot water usage.

Isolation valves are put in place to shut off the solar collection process for various reasons, and an auxiliary water heater is typically plumbed into the system as shown. The purpose is to prevent the loss of hot water when you shut off the collection process using the isolation valves.

An electronic controller senses temperatures at two points shown, and cycles on and off the system's pump which circulates the closed loop thermal conductive fluid through the collector and heat exchanger.

In the event of a power outage your system is vulnerable to freeze damage in cold conditions, use a Vernatherm freeze protection valve to non-electrically drain the collector into the drain back tank.

Closed Loop Pressurized Glycol System

This system is similar to a hydronic base board heating system you would find in many residential dwellings, the only difference is that the base board heating element is eliminated and replaced with a heat exchanger that resides inside a "solar storage tank". Rather than a system that heats the air, this system will heat colder water around it's heat exchanger.

This is closed loop system containing glycol fluid which will not freeze, when the temperature increases its volume will increase thus requiring an "expansion tank" similar to base board heating.

This system is used in many cold climates and does not require a Vernatherm freeze protection valve. An electric controller senses temperatures and cycles on and off the pump as needed.

If in the event of a power outage, your pump will not cycle on, yet your glycol fluid will not freeze.