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Solar Thermal Radiant Floor Heating Adjustment
Radiant floor installations rarely need more than seasonal adjustment. Typically, they are set up at the time of installation and just need to be switched on or off depending on the time of year.
At installation, the ball valve on the heat exchanger bypass stays about 1/3 closed at all times, forcing some of the hot solar fluid through the heat exchanger, but allowing most of it to go to the radiant floor heating (or shunt loop in the off-season).
Layout Patterns for Radiant Floor Tubing
When you opt for radiant floor heating, you opt for the most efficient, cheapest and most comfortable heating available, especially when you combine it with a solar thermal installation. The big question for radiant floor installation is how to lay out the piping that carries the hot solar fluid through the high-mass heating medium.
How to Prepare Pex Tubes for Radiant Heating
Back when modern radiant floor systems were first installed, copper or steel pipes were used. They were embedded in concrete under the floor and hot water ran through them to heat the building. It doesn't take a genius to see where the problems came from:
Can I Integrate a Forced-Air Heating System with Solar Thermal?
This is a common question from people who want to retrofit a solar thermal space heating system. The simple answer is "Yes, you can integrate the two systems." The reality of the process is a little more complicated.
Controls for an Integrated Forced-Air and Solar Thermal Setup
Control in a batch installation
If your solar thermal system has no storage, the heat gathered by the collectors goes straight to the ducting. When heat is needed, both systems are switched on, so hot solar fluid circulates to the heat exchanger and the furnace blower distributes the heat around the building.
Integrating Solar Thermal Space Heating with Hydronic Systems
Most residential buildings that have an existing grid-tied heating system use a hydronic rather than a forced-air system. This is generally better for integration with solar thermal installations, though that's a big generalization: there are so many different layouts, implementations and requirements that it is impossible to state whether integration is guaranteed.
Controls for an Integrated Hydronic and Solar Thermal Setup
Combining a solar thermal heating system with an existing hydronic installation requires not only plumbing and solar equipment but some extra control gear – both electronic and hydronic – to divert fluid when needed. There are several options available in most cases.
In some situations, you will be able to wire the solar thermal setup into the existing thermostat control system so that the water supply passes through the solar storage tank's exchanger when there's enough heat to do some good.
Non-Integrated Solar Thermal Heating Systems
Although it is usually preferable to connect your solar thermal space heating installation into a grid-tied system and have the two work together, it's not always possible. Some retrofits simply do not lend themselves to integration, so you will end up with two separate systems. They can still work together, just not to the same extent.
High Mass Solar Thermal Space Heating
One of the oldest known man-made solar thermal space heating systems was built by the Romans, who constructed radiant floors for their bathhouses over 2,000 years ago. The systems heated the bathing water and the buildings by circulating hot air under the floors, then up through multiple chimneys. Today, radiant floors are not only the most comfortable heating system available, but the most economical – especially when tied into solar thermal heat generation!