What are the passive and active parts of an energy efficient house?

Question

I am doing a project for science on energy efficient houses. My teacher said to use in my project passive parts (parts that don't move, like windows on south side) and active parts (like water moving in roof?) What are some active parts?

Answer 1

We might think of self actuating blinds or shutters that close to keep in or out heat, based on whether the house wants to be kept warm or cool

Actively, we can have heat exchangers that recover heat (or cool) while providing air exchange. This goes further and uses heat pump technology to move air out as cold as outside air, or to pump heat into outbound air.



Systems that gain heat from deep in the ground are usually active, unless one has a hot spring.

A system to heat water flowing into the water heater during use of a shower.. could be passive or active, depending on technology used.

Windows that open to allow convective cooling or just cross ventilation. might be passive or active.

Overhanging roof or awnings to keep sun off  windows would be passive.

Refrigerator that is energy star is an active element.

A panel that collects heat from sunlight might be passive if its heat flows into a plumbing system without assistance. It is part of an active system if it uses pumping or particularly heat-pumping technology.

A heat storage unit is essentially passive, but to get best use of space it may be heat pumped, making it active.

Large hot water tanks are often faulted for lack of efficiency, some prefer tankless. But a large tank used with solar heating even as a preheater for  a tankless heater, allows sun heat to be used well beyond the time the sun goes down.

R2000 standards for insulation are mostly passive, other than for active thermal window shutters.

Aluminum foil under the roof deck is passive. It also ruins asphalt roofing.

Would we think of a cedar hedge that breaks the wind as passive or active? Now a berm that does the same is very passive.

Shade trees to allow comfort without A/C?

Low energy lighting that is not all on or all off, switched by zone. Active?

Photovoltaic panels that provide all the energy the building uses plus a margin... somewhat active, some may not regard as part of efficiency.