Solar heated building designs for cloudy winters

• US 5,524,381 A
• Filed: 05/26/1992
• Issued: 06/11/1996
• Est. Priority Date: 03/19/1991
• Status: Expired due to Fees

• Current Assignee: Day Chahroudi
• Original Assignee: Day Chahroudi
• Inventors: Chahroudi, Day
• Primary Examiner(s): Raduazo, Henry E.
• Application Number:
  US07/888,230
• Time in Patent Office: 1,477 Days
• Field of Search: 47/17 SC, 47/17 RM, 52/173.3, 52/1, 126/419, 126/422
• US Class Current: 47/17
• CPC Class Codes: A01G 9/243 Collecting solar energy in general F24S
• CPC Class Codes: E04C 2/54 Slab-like translucent elements floors for transmitting light E04B5/46; translucent or open-work ceilings E04B9/32, E04B9/34; translucent roof coverings E04D3/06, E04D3/28
• CPC Class Codes: F24S 50/80 for controlling collection or absorption of solar radiation
• CPC Class Codes: F24S 80/50 Elements for transmitting incoming solar rays and preventing outgoing heat radiation; Transparent coverings
• CPC Class Codes: F24S 80/56 characterised by means for preventing heat loss
• CPC Class Codes: Y02A 40/25 Greenhouse technology, e.g. cooling systems therefor
• CPC Class Codes: Y02B 10/20 Solar thermal
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02P 60/12 using renewable energies, e.g. solar water pumping

Abstract

A building including high efficiency transparent insulation and optical shutter solar collector (HETIOSSC) to effectively control heat loss and gain in a passively-solar climate control system. HETIOSSC includes a layer of protective glazing, a transparent insulation, an optical shutter, an optional solar radiation absorbing material and optional heat storage elements. When the building and its heat storage are too warm, the optical shutter layer becomes opaque to prevent overheating. During cloudy and cold winter days, HETIOSSC still has a solar transmission and insulation efficiency great enough to collect sufficient sunlight for heating. Location of HETIOSSC on the roof, rather than the walls, does not alter shape and orientation of a building.

Claims

1. A solar heated building having a roof, with more than half of the area of said roof comprising a solar collector, said solar collector comprising therein a sequence of layers from the top, that is, above, to the bottom, that is, below, including:

a layer of transparent glazing;

a layer of transparent insulation having a top and a bottom side and having a thermal conductivity of less than 0.25 BTU/sq. ft/°

F./hr, and with a solar energy transmission of greater than 40%; and

a layer of optical shutter material with no liquid or gas moving fluid and no macroscopic moving parts, having a transmissive and a non-transmissive state, and located on one of said sides of said transparent insulation layer;

wherein said optical shutter allows solar energy transmission three or more times greater in its transmissive state than in its non-transmissive state.

2. A building as in claim 1, comprising an additional solar radiation absorbing layer located below both said insulation and said optical shutter, said absorbing layer having a solar energy absorptivity of greater than 70%.

3. A building as in claim 2, where a layer of interior finish is below and in proximity to said absorbing layer.

4. A building as in claim 1, comprising additional heat storage elements located below both said insulation and said optical shutter, said storage elements having a thermal capacity of greater than 2 BTU/sq.ft/°

F./hr.

5. A building as in claim 4, comprising an additional solar radiation absorbing layer located adjacent to said storage layer, said absorbing layer having a solar energy absorptivity of greater than 70%.

6. A building as in claim 5, where a layer of interior finish is below and in proximity to said heat storage element and said absorbing layer.

7. A building as in claim 4, where part of said heat storage elements is a layer below and in proximity to said layers of transparent insulation and optical shutter.

8. A building as in claim 7, where part of said heat storage layer is water.

9. A building as in claim 7, where part of said heat storage layer is a phase change material.

10. A building as in claim 4, where part of said heat storage layer is contained in a floor below said roof.

11. A building as in claim 4, where heat is transported from part of said heat storage elements to part of said building'"'"'s interior by means of air circulated by fans through ducts.

12. A building as in claim 11, where, for the purpose of not transporting humidity along with said transported heat:

an air to air heat exchanger is interposed between said heat storage element and part of said building'"'"'s interior;

and separate fans drive the air circulation loops on either side of said heat exchanger.

13. A building as in claim 1, where said optical shutter:

becomes substantially non-transmissive primarily by reflecting solar radiation;

and is located below said transparent insulation.

14. A building as in claim 1, where said optical shutter:

becomes substantially non-transmissive primarily by absorbing solar radiation; and

is located above said transparent insulation.

15. A building as in claim 1, where said optical shutter becomes substantially non-transmissive to solar radiation above a preselected temperature and becomes substantially transparent to solar radiation below a preselected temperature.

16. A building as in claim 1, where said optical shutter becomes substantially reversibly non-transmissive to solar radiation in response to an applied voltage or current.

17. A building as in claim 1, where said transparent insulation includes one or more low emissivity layers.

18. A building as in claim 1, where said transparent insulation includes one or more low emissivity layers and one or more convection baffles which are substantially transparent to both solar and thermal radiation.

19. A building as in claim 1, where said transparent insulation includes one or more low emissivity layers and one or more layers of vacuum adjacent to said low emissivity layers.

20. A building as in claim 1, where said transparent insulation includes one or more layers of honeycomb material which is:

oriented with its openings approximately perpendicular to the surface of said building'"'"'s roof or floors;

substantially non-absorbing of solar radiation;

substantially specular in its transmission and reflection of solar radiation;

substantially absorbing of thermal radiation.

21. A building as in claim 1, where said transparent insulation is made from one or more layers of aerogel.

22. A building as in claim 1, where heat is transported from said heat storage elements to parts of said building'"'"'s interior by means of water circulated by pumps through pipes.

23. A building as in claim 1, with an additional solar still comprised of:

an evaporator of impure water interior to said building from said solar collector;

a condenser and collector of distilled water comprised of;

part of the interior surface of said solar collector, and/or an air to air heat exchanger; and

a collection trough.

24. A building as in claim 23, where said evaporator includes plants in a greenhouse.

25. A building as in claim 1, where at least part of said solar collector comprises part of the envelope of a greenhouse attached to said building.

26. A building as in claim 25 where at least part of said greenhouse is at least part of a top story or attic of said building.