Solartrex wo sich Ökonomie und Ökologie treffen

Cold city or well water enters the boiler and is slowly heated up by an electric heater element to 120 - 150° F. This is the common way to heat water in the United States because this heating system is inexpensive.

Contra:
- The most expensive way to heat water.
- Makes up for about 1/3 of your electricity bill.
- Heats up a reservoir of water even when you do not need it.
- Lasts about 12 Years.

On demand tankless water heater

There is no stored hot water. On demand, cold water passes through a heat exchanger and is instantly heated to the desired temperature.
The most common is the electric powered version, but the gas powered version is the more efficient since there is no electric energy lost in transport and transformation through the grid.

Contra of the electric version:
- 2/3 of original energy is lost.

Contra of the gas version:
- More complicated to set up.
- You have to order gas.
- Gas tank sitting around outside.

Solar water heater with storage tank and no backup

Cool water from the lower part of the storage tank is pump through the solar water heater where sunlight is transformed into heat that warms the water. The warmed water enters the storage tank at the upper part. Warm water is lighter then cold water so it collects at the upper part. The warm water drawn from the storage tank is replaced by cold city or well water. When the stored warm water is used up you need to wait for the sun to shine.

Contra:
-No warm water when sun is not active enough.
-No freeze protection.

Freeze protected Solar water heater with heat exchanger

In climates with temperatures below freezing you need to mix antifreeze in the water going out to the solar collector. Since you do not want anti-freeze in your coffee or shower water, you have to separate the fresh water from the freeze protected water. The anti-freeze water is kept in a close loop. The sun warmed water passes through a coil inside the storage tank and transfers the heat to the fresh water.

Solar water heater with backup conventional water heater

For warm water at all times, you need to back up the solar heater which does not work when the sun is not shining. If you keep your existing conventional water heater as a backup for a rainy day, the solar heater preheats the water going into the boiler tank. The boiler brings the water temperature to the desired 120°F and keeps it there, even if there is no water being used.

Pro:
- Always warm water until both tanks are cold.
- Big savings compared to conventional heating.
- Make use of your existing boiler water heater.

Solar water heater with complementary thankless water heater

Endless warm water is achieved by a tankless water heater backing up the solar water heater. Only if the water in the solar storage tank is not warm enough, it will be brought up to the desired temperature while it passes through the tankless heater.

There are two "on-demand" thankless heater systems, gas- or electric powered. (See above "on demand tankless heater")

Pro:
- Endless warm water.
- Big savings compared to conventional heating.
- Only uses energy on demand.
- Uses less space inside your house since there is no second tank needed.

T-Rex System freeze protected and inexpensive

The T-Rex system stores warm water mixed with anti-freeze close to the solar heater in your attic. The distances are smaller so the pump is smaller and uses less energy.

Cold fresh water is warmed up by passing through a the heat exchanger inside the storage tank. A tankless heater backs up the system. Since the solar heater and the storage tank are pressureless, there is no need for a expansion tank. It is easier to install and makes leaks less likely.

Pro:
- Endless warm water.
- Big savings compared to conventional heating.
- Only uses energy on demand.
- Uses no space in house.
- Less energy used for pumping.
- No pressure on solar heater.
- No expansion tank needed.
- Easy to install and maintain:
- Freeze protected system.