The subfloor can be insulated by adding insulation material between the floor joists. This can be done by placing fiberglass batts, foam boards, or spray foam insulation. It is important to ensure that the insulation material fits snugly between the joists to prevent air leakage. Additionally, sealing any gaps or cracks in the subfloor can also help improve insulation. **

To re-insulate a subfloor, you can start by removing the existing flooring to access the subfloor. Next, you can add insulation material such as fiberglass batts, foam boards, or spray foam insulation between the floor joists. Make sure to seal any gaps or cracks to prevent air leakage. Finally, reinstall the flooring once the insulation is in place. **

For a single-family house built with timber framing, the most common type of subfloor to be placed under the foundation slab is a layer of compacted gravel or crushed stone. This type of subfloor provides a stable and level base for the foundation slab to be poured on top of. It also helps to improve drainage and prevent moisture from accumulating under the slab. Additionally, a layer of vapor barrier may be placed on top of the gravel to further protect the foundation from moisture. **

Self-luminous bodies are objects that emit their own light, as opposed to reflecting light from another source. Examples of self-luminous bodies include stars, the sun, and certain types of light bulbs. These objects generate their own energy through processes like nuclear fusion or electrical current, which produces light as a byproduct. **

No, the luminous clock is not radioactive. The luminescence in the clock is typically achieved using a phosphorescent material that absorbs light and then slowly releases it over time. This process does not involve any radioactive materials. The glow from the clock is simply a result of this light-absorption and emission process. **

A luminous point is a theoretical concept used in physics and optics to represent a source of light that emits light in all directions. It is often used as a simplification in the study of light and its behavior, allowing for easier calculations and analysis. In reality, a luminous point does not exist as a physical object, but it is a useful tool for understanding the behavior of light in various systems. **

Radiant energy is a type of energy that travels through space in the form of electromagnetic waves. It includes visible light, radio waves, microwaves, and other forms of electromagnetic radiation. Radiant energy is produced by the movement of charged particles and is essential for many natural processes, such as photosynthesis in plants and the warmth we feel from the sun. It is also used in various technologies, such as solar panels and communication devices. **

The luminous intensity is specified for reflector lamps because it measures the amount of light emitted in a specific direction, which is important for directional lighting applications such as spotlights and floodlights. Reflectors are designed to control and direct light in a specific direction, so specifying luminous intensity helps to ensure that the lamp is suitable for its intended purpose. Luminous flux, on the other hand, measures the total amount of visible light emitted by a source in all directions, which may not be as relevant for reflector lamps where the focus is on directing light in a specific direction. **