U.S. patent application number 11/387417 was filed with the patent office on 2006-09-28 for automatic energy-efficient bathroom exhaust fan controller.
Invention is credited to Russell E. Bruhnke, Christopher J. Kimble.
Application Number | 20060213000 11/387417 |
Document ID | / |
Family ID | 37033700 |
Filed Date | 2006-09-28 |
United States Patent
Application |
20060213000 |
Kind Code |
A1 |
Kimble; Christopher J. ; et
al. |
September 28, 2006 |
Automatic energy-efficient bathroom exhaust fan controller
Abstract
An automatic control system for an exhaust fan of a room having
a water dispensing conduit is disclosed. The system includes a
control module that controls delivery of electricity to the exhaust
fan to activate and deactivate the exhaust fan, and a sensor
suitable for mounting on the water dispensing conduit. The sensor
senses temperature of the water dispensing conduit and when a
temperature above a predetermined temperature value is reached on
the water dispensing conduit, the sensor transmits a control signal
to the control module. The temperature increase is due to hot water
flowing though the water dispensing conduit (e.g., a shower pipe).
Upon receipt of the control signal, the control module activates
the exhaust fan for a user selectable time period.
Inventors: |
Kimble; Christopher J.;
(Pine Island, MN) ; Bruhnke; Russell E.;
(Rochester, MN) |
Correspondence
Address: |
QUARLES & BRADY LLP
411 E. WISCONSIN AVENUE
SUITE 2040
MILWAUKEE
WI
53202-4497
US
|
Family ID: |
37033700 |
Appl. No.: |
11/387417 |
Filed: |
March 23, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60665650 |
Mar 25, 2005 |
|
|
|
Current U.S.
Class: |
4/211 |
Current CPC
Class: |
F24F 11/30 20180101;
F24F 7/007 20130101; F24F 2007/001 20130101; F24F 2110/00
20180101 |
Class at
Publication: |
004/211 |
International
Class: |
E03D 9/04 20060101
E03D009/04 |
Claims
1. An automatic control system for an exhaust fan of a room having
a water dispensing conduit, the system comprising: a control module
that controls delivery of electricity to the exhaust fan to
activate and deactivate the exhaust fan; and a sensor suitable for
mounting on the water dispensing conduit, the sensor sensing
temperature of the water dispensing conduit, the sensor
transmitting a control signal to the control module when a
temperature above a predetermined temperature value is reached on
the water dispensing conduit, wherein upon receipt of the control
signal, the control module activates the exhaust fan.
2. The system of claim 1 wherein: the control module activates the
exhaust fan by providing electricity to the fan.
3. The system of claim 2 wherein: the control module includes a
timer circuit that provides electricity to the fan for a
predetermined time period after which the fan is deactivated.
4. The system of claim 3 wherein: the predetermined time period is
a variable time period selectable by a user.
5. The system of claim 2 wherein: the control module includes a
timer circuit that provides electricity to the fan for a
predetermined time period after temperature falls below the
predetermined temperature value.
6. The system of claim 5 wherein: the predetermined time period is
a variable time period selectable by a user.
7. The system of claim 1 wherein: the control module includes a
control for setting the predetermined temperature value.
8. The system of claim 1 wherein: the water dispensing conduit is a
shower pipe.
9. The system of claim 1 wherein: the water dispensing conduit is a
bathtub spigot.
10. The system of claim 1 wherein: the control signal is a radio
frequency signal.
11. An automatic control system for an electrical device in a room
having a water dispensing conduit, the system comprising: a control
module that controls delivery of electricity to the electrical
device to activate and deactivate the electrical device; and a
sensor suitable for mounting on the water dispensing conduit, the
sensor sensing temperature of the water dispensing conduit, the
sensor transmitting a control signal to the control module when a
temperature above a predetermined temperature value is reached on
the water dispensing conduit, wherein upon receipt of the control
signal, the control module activates the electrical device.
12. The system of claim 11 wherein: the control module activates
the electrical device by providing electricity to the electrical
device.
13. The system of claim 12 wherein: the control module includes a
timer circuit that provides electricity to the electrical device
for a predetermined time period after which the electrical device
is deactivated.
14. The system of claim 13 wherein: the predetermined time period
is a variable time period selectable by a user.
15. The system of claim 12 wherein: the control module includes a
timer circuit that provides electricity to the electrical device
for a predetermined time period after temperature falls below the
predetermined temperature value.
16. The system of claim 15 wherein: the predetermined time period
is a variable time period selectable by a user.
17. The system of claim 11 wherein: the control module includes a
control for setting the predetermined temperature value.
18. The system of claim 11 wherein: the water dispensing conduit is
a shower pipe.
19. The system of claim 11 wherein: the water dispensing conduit is
a bathtub spigot.
20. The system of claim 11 wherein: the electrical device is a
blower.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Patent Application No. 60/665,650 filed Mar. 25, 2005.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention relates to an automatic energy-efficient
controller for a room exhaust fan.
[0005] 2. Description of the Related Art
[0006] Exhaust fans are used to ventilate rooms, such as bathrooms,
to prevent humidity from accumulating in the room. Conventional
exhaust fans are activated by a wall switch turned on by the home
owner. Many homes do not have electronic or mechanical timers
operating the bathroom exhaust fan, and consequently when the fan
is turned on, it may remain on for a much longer time than is
necessary to remove the moist air. Thus much energy is wasted, as
the fan expels air that has been expensively heated (in the winter)
or cooled (in the summer).
[0007] Consequently, devices have been proposed to automatically
control bathroom exhaust fans. Japanese Patent Application No.
JP3286940 describes a control device for a bathroom fan where the
fan is driven for a preset time.
[0008] Japanese Patent Application Nos. JP63254339, JP3117838,
JP3036445, JP58156134, JP10110982, JP10047719, JP9318111 and
JP7120026 describe a control device for a bathroom fan where a
humidity sensor provides a signal to start and/or stop the fan. In
a related application, the device of Japanese Patent Application
No. JP62194136 uses a humidity reading to determine an operating
time for the fan. However, humidistat control tends to be imprecise
and slow to respond, and is furthermore useless during periods of
high humidity in homes that are not air-conditioned.
[0009] Japanese Patent Application Nos. JP63254339, JP2003279091
and JP10110982 describe a control device for a bathroom fan where a
temperature sensor provides a signal to start and/or stop the fan.
However, temperature control also tends to be imprecise and slow to
respond.
[0010] Japanese Patent Application No. JP2247436 describes a
control device for a bathroom fan in which a hot water feeding
switch for a bath also starts a ventilating fan. However, this
control device appears to require mounting the control device
behind a room wall in line with a hot water pipe.
[0011] Japanese Patent Application No. JP2004144383 describes a
control device for a bathroom fan where a bath water level sensor
provides a signal to start the fan. This device may be slow to
respond in that it may take a long time before water reaches the
sensor level.
[0012] Japanese Patent Application Nos. JP1006634, JP9318111 and
JP5180475 describe a control device for a bathroom fan where a
sensor that detects a person provides a signal to start and/or stop
the fan. These devices may be inefficient in that fan operation may
be triggered when a person enters a room momentarily.
[0013] Japanese Patent Application No. JP3236538 describes a
control device for a bathroom fan where a light sensor which
detects steam provides a signal to start and/or stop the fan. Like
a humidity controller for a fan, this device may be imprecise and
slow to respond.
[0014] In view of the disadvantages of known automatic controllers
for a bathroom exhaust fan, there exists a need for an improved
automatic energy-efficient bathroom exhaust fan controller.
SUMMARY OF THE INVENTION
[0015] The present invention provides an automatic energy-efficient
controller for a room exhaust fan. The invention turns on a
bathroom exhaust fan automatically when someone takes a shower. A
thumb-sized smart sensor, clipped onto the shower pipe adjacent to
the shower head, detects the temperature increase when the
hot-water valve is opened. The sensor then communicates wirelessly
with a controller module built into the fan's wall-mounted switch,
turning the fan on for a user-selectable time interval. A timer
permits the homeowner to select the time delay. The smart sensor
could also be clipped onto the bathtub faucet. The invention can be
installed easily by a homeowner, and is attractive to businesses
participating in the burgeoning home-automation retail market.
[0016] Thus, the invention provides an automatic control system for
an exhaust fan of a room having a water dispensing conduit. The
system includes a control module that controls delivery of
electricity to the exhaust fan to activate and deactivate the
exhaust fan, and a sensor suitable for mounting on the water
dispensing conduit wherein the sensor senses temperature of the
water dispensing conduit and the sensor transmits a control signal
to the control module when a temperature above a predetermined
temperature value is reached on the water dispensing conduit. Upon
receipt of the control signal, the control module activates the
exhaust fan. The control signal may be a radio frequency
signal.
[0017] In one version of the invention, the control module
activates the exhaust fan by providing electricity to the fan. The
control module may include a timer circuit that provides
electricity to the fan for a predetermined time period after which
the fan is deactivated, and the predetermined time period may be a
variable time period selectable by a user. The control module may
include a control for setting the predetermined temperature
value.
[0018] In another version of the invention, the control module
includes a timer circuit that provides electricity to the fan for a
predetermined time period after temperature falls below the
predetermined temperature value. The predetermined time period may
be a variable time period selectable by a user.
[0019] In one use of the invention, the water dispensing conduit is
a shower pipe. In another use, the water dispensing conduit is a
bathtub spigot.
[0020] It is an advantage of the present invention that the user
does not have to remember to turn on a bathroom exhaust fan. Yet
moist air is reliably removed from the bathroom, where it otherwise
could promote mold growth or accumulate in exterior wall
insulation, possibly damaging the house.
[0021] These and other features, aspects, and advantages of the
present invention will become better understood upon consideration
of the following detailed description, drawing and appended
claims.
DESCRIPTION OF THE DRAWING
[0022] FIG. 1 shows an elevational view of a wall of a bathroom
including an automatic energy-efficient controller and an exhaust
fan according to the invention.
DESCRIPTION OF THE INVENTION
[0023] Looking at FIG. 1, there is shown a bathroom 10 having a
side wall 12 and a ceiling 14. Mounted in the ceiling 14 is an
exhaust fan 20 that exhausts air from the interior of the bathroom
10 and out a conduit 22 to the attic or outside atmosphere through
the roof. A wall mounted module 30 communicates via electrical line
32 with the exhaust fan 20 to provide electricity to the fan 20 to
operate the fan. The module 30 includes a control 36 that allows a
user to set the temperature threshold for allowing the fan to be
activated. The module 30 also includes a control 34 that allows a
user to set the operating time period for the fan 20 after the
temperature falls below the threshold.
[0024] The bathroom 10 includes a shower/bath tub stall 40 having a
shower pipe 42 that terminates in a shower head 44 and having a
bathtub spigot 46. Mounted on the shower pipe 42 is a smart sensor
50 that detects the temperature increase in the shower pipe 42 when
the hot-water valve is opened. Alternatively, the smart sensor 50
could be clipped onto the bathtub spigot 43. When a temperature
increase is sensed by the sensor 50, the sensor 50 communicates
wirelessly with the module 30, which sends a signal to the fan 20
turning the fan 20 on for the user-selectable time interval
selected with dial 34. In one form, the sensor 50 communicates
wirelessly with the module 30 by way of an radio frequency
transmitter and receiver.
[0025] Batteries in the smart sensor 50 can be quite small, yet
would be expected to last at least 6 months, because a
microcontroller in the sensor 50 would be asleep >99% of the
time. It would wake up just once or twice per minute to sense the
temperature of the shower pipe 42. An IC such as National
Semiconductor's LM35 would be one suitable temperature-sensing
component of the sensor 50. A thermo-mechanical switch (e.g.,
bimetallic spring) could be used to activate the circuitry, as an
alternative to using the microcontroller's internal watchdog
timer.
[0026] Thus, the invention provides an automatic energy-efficient
controller for a room exhaust fan. Advantageously, the user does
not have to remember to turn on a bathroom exhaust fan because of
the automatic operation of the controller.
[0027] While in one example form the invention is an automatic
control system for an exhaust fan of a room having a water
dispensing conduit, the invention is suitable for controlling any
electrical device in a room having a water dispensing conduit. For
example, the invention could control operation of an electric towel
warmer or a lighting system or an electrically controlled fragrance
dispenser. Also, another electrical device that could be controlled
is a ventilation blower for a shower enclosure. It would turn on a
few minutes after the shower has ended, and stay on for a
programmed time interval, in order to dry off the shower walls and
thereby to prevent the growth of mold and mildew. Such a blower
system can force air through a 3-inch duct located in a rear bottom
corner of the shower, so that the air will circulate in a vortex
and exit over the top of the shower door.
[0028] Thus, although the present invention has been described in
detail with reference to certain embodiments, one skilled in the
art will appreciate that the present invention can be practiced by
other than the described embodiments, which have been presented for
purposes of illustration and not of limitation. Therefore, the
scope of the appended claims should not be limited to the
description of the embodiments contained herein.
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