Underfloor Solar Heating

Heat your home with free energy from the sun

With a DSHH Solar powered underfloor heating system from Energy Efficient Homes.

Digital Self-Heating Home

Imagine slashing your heating energy bills by half or more. The key is year round, low cost, thermal solar storage and a dedicated computer to manage the heating and transfer of energy. With the Digital Self-Heating Home (DSHH) system you can store the massive amount of summer heat AND use most of the winter solar heat to heat your home and even heat your hot water. The DSHH system can also use a log fired wetback/boiler and or a hot water heat pump for backup.

The DSHH system is designed as Background Heat in the serviced part of the home, and helps prevent the living areas from dropping below +18c, once the system storage has reached its optimal holding temp.

How it works

The key concept is excess heat is stored in the dirt under the house, and extracted as required to warm it. This stored heat takes a long time to become useful, in the interim the winter solar heat is injected directly into the slab, warming the home.

There are 3 phases to the basic DSHH system + options like solar hot water, wetback integration and heat pump operation. All facets of the operation are controlled by a custom designed solar controller with monitored sensors for: Solar Panel(s), Hot Water H & L, Slab, Heat Core, Wetback/Boiler.

Phase 1: Directly Heat the Home
1. As above, the sun heats up the evacuated tube, collector collectors which heats the transfer fluid; a water and antifreeze mix.
2. The controller checks the house temperature, if it needs heat it:
3. The Digital controller directs the heat from the solar panels, through controlling right valves and pumps, directly to the Slab
4. The fluid circulates in the slab until the controller decides the room is up to the preset temperature, at which time it turns the slab heating off, and goes back to phase 1
above.

Phase 2: Store the solar heat
1. The sun heats up the collector tubes which in turn heats the water inside the pipes.
2. The controller decides it doesn’t need the heat anywhere else and sends the excess heat to the Thermal Heat Core Storage Area. This is a HUGE area the size of the house, under the slab.
3. The Digital controller opens the correct control valves and the pumps & sends the surplus heat to the Heat Core, especially valid in summer.
4. The water circulates through the Core releasing its’ heat to the heat core and then the cooled fluid enters the Solar collector to be reheated.

Phase 3: Use the Stored heat
1. When there is no sun, (or other heat such as a wetback or hot water heat pump).
2. And if heat is required in the home, the controller extracts heat from the Heat Core.
3. The correct valves are opened and the heat is pumped from the Heat Core to the Slab.
4. The warm fluid circulates through the slab warming it and the home.

All heat, including excess wetback heat, if NOT needed for immediate use is stored in the Heat Core.
It will take at least a full summer season of sunlight to begin charging up the heat core.
Once heated, the thermal mass of the insulated slab will retain warmth for extended periods.

Subfloor Design Requirements for a Digital Self-Heating Home

A well insulated sub floor is required for installation of a DSHH underfloor heating system.
North Island: >900mm ICF Slab sub-wall
South Island: >1500mm ICF Slab sub-wall
Under-slab EPS insulation >70mm
Insulated slab edges

Thermally Efficient House Design Required

The system works best in a thermally efficient home and is not currently designed to be retrofitted to an existing home.

Solar Hot Water Option

Solar hot water qualifies for the EECA government solar rebate scheme.

Option 1: Fully integrated with the DSHH system. Extra collectors are included to increase capacity. This system makes the Hot water priority, however, in summer, a large solar array as used by the DSHH system, can heat even large HWC (Hot Water Cylinders/Tanks) quite quickly before reverting to house heating and storage.

Option 2: Matching but separate solar hot water system, may include overheat dump to DSHH. In summer the HWC can reach its pre-set heat point quite early.

DSHH Limitations

The DSHH system needs to be built into a new home during the design phase. For optimal design parameters, the system works best with a thermally efficient home and can be integrated in to many designs before foundation is started. Underground water movement may require additional excavation, compaction, moisture barriers and insulation.

Expectations: In optimal locations in the North Island, excluding the plateau, design is for a standard whole-house background temp of 18c for most of the winter, and 18c for 75% of the winter in Southland and the plateau areas. These figures will vary based on house design, earth, thermal mass, temperature set point, as well as summer and winter sunshine hours. The system will inject solar heat even in winter under freezing conditions outside. It is anticipated the system will improve over time as the heat core storage increases in thermal energy.

Contact

For further information and pricing, contact:

Energy Efficient Homes Limited
44 Aroha Ave, St. Lukes
Auckland 1025
New Zealand

Phone +64 9 815-6664

www.eehnz.com