U.S. patent application number 13/641525 was filed with the patent office on 2013-02-14 for system and method for ventilating a defined space.
This patent application is currently assigned to DRYVENT SOLUTIONS OF SCANDINAVIA AB. The applicant listed for this patent is Elisabet Ehn, Mike Hoglund, Lai Kim Lim, Andreas Pfister. Invention is credited to Elisabet Ehn, Mike Hoglund, Lai Kim Lim, Andreas Pfister.
Application Number | 20130040550 13/641525 |
Document ID | / |
Family ID | 44303422 |
Filed Date | 2013-02-14 |
United States Patent
Application |
20130040550 |
Kind Code |
A1 |
Pfister; Andreas ; et
al. |
February 14, 2013 |
SYSTEM AND METHOD FOR VENTILATING A DEFINED SPACE
Abstract
The present invention relates to a system (100) for ventilating
a defined space (102), such as for example an enclosed or at least
partly enclosed basement, crawlspace or attic. The system (100)
comprises a control unit (110) connected to at least one inside
sensor (104), at least one outside sensor (106) and a controllable
fan (108), the control unit (110) being configured to operate the
controllable fan (102) if the absolute humidity (AH.sub.out)
outside of the defined space (102) is lower or equal to the
absolute humidity (AH.sub.in) within the defined space (102), and
the temperature (T.sub.in) within the defined space (102) is above
a predetermined temperature when the temperature (T.sub.in) outside
of the defined space (102) is below the temperature (T.sub.in)
within the defined space (102). Advantages of the invention include
energy efficient ventilation of the defined space and a high level
of protecting from moisture related problems.
Inventors: |
Pfister; Andreas; (Goteborg,
SE) ; Hoglund; Mike; (Harestad, SE) ; Lim; Lai
Kim; (Goteborg, SE) ; Ehn; Elisabet;
(Jonkoping, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Pfister; Andreas
Hoglund; Mike
Lim; Lai Kim
Ehn; Elisabet |
Goteborg
Harestad
Goteborg
Jonkoping |
|
SE
SE
SE
SE |
|
|
Assignee: |
DRYVENT SOLUTIONS OF SCANDINAVIA
AB
Goteburg
SE
|
Family ID: |
44303422 |
Appl. No.: |
13/641525 |
Filed: |
April 29, 2011 |
PCT Filed: |
April 29, 2011 |
PCT NO: |
PCT/SE2011/000075 |
371 Date: |
October 16, 2012 |
Current U.S.
Class: |
454/239 ;
454/249; 454/333 |
Current CPC
Class: |
F24F 2110/10 20180101;
F24F 11/30 20180101; F24F 2110/22 20180101; F24F 2110/20 20180101;
F24F 11/0001 20130101 |
Class at
Publication: |
454/239 ;
454/249; 454/333 |
International
Class: |
F24F 11/02 20060101
F24F011/02; F24F 13/10 20060101 F24F013/10; F24F 7/06 20060101
F24F007/06 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 29, 2010 |
SE |
1000435-6 |
Claims
1. A system for ventilating a defined space, comprising: at least
one inside sensor configured to measure temperature and relative
humidity within the defined space; at least one outside sensor
configured to measure temperature and relative humidity outside of
the defined space; a controllable fan adapted to ventilate the
defined space; and a control unit connected to the at least one
inside sensor, the at least one outside sensor (106) and the
controllable fan, the control unit being configured to determine
absolute humidity within the defined space and absolute humidity
outside of the defined space, wherein the control unit is further
configured to operate the controllable fan if: the absolute
humidity outside of the defined space is lower or equal to the
absolute humidity within the defined space, and the temperature
within the defined space is above a predetermined temperature
threshold when the temperature outside of the defined space is
below the temperature within the defined space.
2. The system of claim 1, wherein the control unit is further
configured to only operate the controllable fan if also the
temperature outside the defined space is above a predetermined
temperature threshold when the temperature outside of the defined
space is below the temperature within the defined space.
3. The system of claim 1, wherein the predetermined temperature
threshold is within the range of 3-10.degree. C., preferably
4-8.degree. C. and most preferably 5-6.degree. C.
4. The system of claim 1, wherein the defined space is at least one
of a basement, a crawlspace, a boat, an attic, a storage room, a
caravan, a trailer, a cabin, a container.
5. The system of claim 1, wherein the system comprises at least two
outside sensors arranged on opposite sides of the defined
space.
6. The system of claim 1, wherein the system further comprises at
least one controllable valve connected to the control unit, and the
control unit is further configured to close the at least one
controllable valve if the absolute humidity outside of the defined
space is higher than the absolute humidity within the defined
space.
7. The system of claim 6, wherein the system further comprises a
dehumidifier connected to and controllable by the control unit, the
control unit further being configured to close the at least one
valve and operate the dehumidifier if the relative humidity within
the defined space is above a predefined humidity threshold.
8. The system of claim 7, wherein the predetermined humidity
threshold is within the range of 50-90%, preferably 60-80% and most
preferably 65-75%.
9. The system of claim 1, wherein the system further comprises an
operator accessible logger connected to the control unit and
configured to log data from the inside and/or outside
sensor(s).
10. A method for ventilating a defined space, the method comprising
the steps of: acquiring temperature and relative humidity within
the defined space using at least one inside sensor; acquiring
temperature and relative humidity outside of the defined space
using at least one outside sensor; determining absolute humidity
within the defined space; determining absolute humidity outside of
the defined space; and operating a controllable fan if: the
absolute humidity outside of the defined space is lower or equal to
the absolute humidity within the defined space, and the temperature
within the defined space is above a predetermined temperature
threshold when the temperature outside of the defined space is
below the temperature within the defined space.
11. The method of claim 10, wherein the controllable fan is
operable only if also the temperature outside the defined space is
above a predetermined temperature threshold when the temperature
outside of the defined space is below the temperature within the
defined space.
12. The method of claim 10, further comprising the step of logging
data from the inside and/or outside sensor(s).
13. The system of claim 1, wherein the predetermined temperature
threshold is within the range of 4-8.degree. C.
14. The system of claim 1, wherein the predetermined temperature
threshold is within the range of 5-6.degree. C.
15. The system of claim 7, wherein the predetermined humidity
threshold is within the range of 60-80%.
16. The system of claim 7, wherein the predetermined humidity
threshold is within the range of 65-75%.
Description
TECHNICAL FIELD
[0001] The present invention relates to a system and method for
ventilating a defined space, such as for example an enclosed or at
least partly enclosed basement, crawlspace, attic or trailer.
BACKGROUND OF THE INVENTION
[0002] There exists a plurality of different types of foundation
used when constructing a building, such as for example a
residential house. The most common types are crawlspaces and slab
foundations, where crawlspaces generally are considered to possibly
have some advantages over slab foundations. For example,
crawlspaces, forming a defined space, offer a convenient access to
pipes, substructures and a variety of other areas that may be
difficult or expensive to access otherwise.
[0003] However, crawlspaces need to be ventilated with outside air,
as water from the damp earth, humidity entering from crawlspace
vents, and moisture seeping through porous concrete will create a
perfect environment for mold, mildew to form on any surface in the
crawlspace, especially wood floors and surfaces, drywall and some
types of insulation. If not paying proper attention, molds, spores,
bacteria, higher levels of chemical vapors and/or radon may migrate
into the house.
[0004] Accordingly, there is a general desire to regulate the
ambient humidity of the crawlspace interior to maintain reduced
moisture levels to preserve the structural integrity of the house.
For example, WO08039149 tries to solve this by controlling the
supply of heat inside the crawlspace, based on known information
about growing time and growing conditions for occurring mildew and
rot fungi and absorption of moisture in occurring materials,
possibly secures a climate where moisture-related damage cannot
arise.
[0005] However, even though WO08039149 provides some relief to the
inherent problems with crawlspaces, the supply of heat may be
energy inefficient for the owner of the house. Accordingly, there
exists a need for an effective and convenient system for use in
monitoring and protecting defined spaces that are susceptible to
moisture damage.
SUMMARY OF THE INVENTION
[0006] According to an aspect of the invention, the above is at
least partly met by a system for ventilating a defined space,
comprising at least one inside sensor configured to measure
temperature and relative humidity within the defined space, at
least one outside sensor configured to measure temperature and
relative humidity outside of the defined space, a controllable fan
adapted to ventilate the defined space, and a control unit
connected to the at least one inside sensor, the at least one
outside sensor and the controllable fan, the control unit being
configured to determine absolute humidity within the defined space
and absolute humidity outside of the defined space, wherein the
control unit is further configured to operate the controllable fan
if the absolute humidity outside of the defined space is lower or
equal to the absolute humidity within the defined space, and the
temperature within the defined space is above a predetermined
temperature threshold when the temperature outside of the defined
space is below the temperature within the defined space.
[0007] The present invention is based on the understanding that it
may be advantageous to control the operation of the forced
ventilation based on a comparison of the "indoor" absolute humidity
and the "outdoor" absolute humidity rather than being based on the
corresponding relative humidity in/outside of the defined space as
is the case with some prior art ventilation systems. Using the
absolute humidity inside/outside of the defined space further
increases the reliability of the system and thereby the possibility
of protecting the defined space from e.g. moisture related problems
and/or damages.
[0008] In cases where the ground of the enclosed space is humid,
the system may be complemented with a vapor barrier on the ground
to keep moisture from evaporating into the air due to the increased
airflow through the enclosed space.
[0009] On top of this, and as is noted above, the defined space is
not ventilated if the inside temperature is below a predefined
temperature threshold and the outside temperature is below the
inside temperature. Preferably, the predetermined temperature
threshold is within the range of 3-10.degree. C., preferably
4-8.degree. C. and most preferably 5-6.degree. C. Thereby, the
energy efficiency of the system is further increased as it has been
found not necessary to ventilate the defined space outside this
condition, i.e. when the inside temperature for example is below
3-10.degree. C. as essentially no moisture related problems and/or
damages will exist at this temperature. By not having to ventilate
the defined space at below the above exemplified predefined
temperature threshold, warm air within the defined space will not
be expelled from the defined space, possibly affecting other for
example living spaces adjacently arranged with the defined space.
Also, by not ventilating at below the specific temperature, warm
and possibly humid air from the adjacently arranged spaces will not
be drawn into the crawlspace by mistake, possibly affecting the
humidity levels within the enclosed space. In some cases it may
however be necessary/useful to also ventilate the defined area even
if the inside temperature is below the predefined temperature
threshold. In such cases it is however desirable to ventilate in a
restrictive manner, possibly during shorter time periods.
[0010] Advantageously, the control unit is further arranged to, in
combination with the above two conditions, only operate the
controllable fan if also the temperature outside the defined space
is above a predetermined temperature threshold when the temperature
outside of the defined space is below the temperature within the
defined space. This further increases the reliability of the
system.
[0011] Preferably, the enclosed or at least partly enclosed defined
space is selected from a group comprising a basement, a crawlspace,
an attic, a storage room, a caravan, a trailer and a cabin. Another
defined space that is susceptible to moisture damage is the
interior space of boats. In particular, the engine rooms and the
interior cabins of boats that are stored at marinas can easily
become mildewed, giving the boats a musty odor and damaging the
materials of the boats.
[0012] In a preferred embodiment the system comprises at least two
outside sensors arranged on opposite sides of the defined space,
for example one outside sensor arrange at the northern side of the
defined space and one sensor arranged at the southern side of the
defined space. Further sensors, inside and/or outside of the
defined space may of course be possible and within the scope of the
invention. Additionally, by providing the system with at least one
controllable valve connected to the control unit, for example two
controllable valves arranged on the northern and southern side of
the defined space, respectively, and configured to allow for supply
of air to the defined space, it may be possible to ventilate the
defined space using air from a side of the defined space where
conditions are the most favorable.
[0013] Additionally, in some conditions it may also be possible to
close the at least one controllable valve if the absolute humidity
outside of the defined space is higher than the absolute humidity
within the defined space.
[0014] In some cases it may be possible to further equip the system
with a dehumidifier connected to and controllable by the control
unit, where the control unit further may be configured to close the
at least one valve and operate the dehumidifier if the relative
humidity within the defined space is above a predefined humidity
threshold, the humidity threshold possibly being within the range
of 50-90%, preferably 60-80% and most preferably 65-75%. Operating
the dehumidifier may be necessary if conditions are very
unfavorable and obvious moisture related problems may exist. Such
conditions may for example relate to specific weather conditions
and/or due to construction related issues.
[0015] Preferably, the system further comprises an operator
accessable logger connected to the control unit and configured to
log data from the inside and/or outside sensor(s). The logger may
be for example comprise a digital storage means such as an USB or a
flash memory card, e.g. CompactFlash, Memory Stick, Secure digital
etc and be accessed by the home owner or any other possibly remote
and valid users for reviewing the conditions over a longer time
period, such as over a month, quarter, year and so on for
determining the structural integrity of the house.
[0016] Alternatively or additionally the logger may be connected to
a remote server where the information from the sensor(s) is stored.
Thereby, other valid users, such as potential house buyers, house
brokers, etc. may access the information to draw conclusions as to
the health of the house. The transmission may be wired or wireless,
including for example wired connections like USB, FireWire, VGA, or
similar, and wireless connections like WLAN, CDMA, GSM, GPRS, 3G
mobile communications, 4G mobile communications, Bluetooth,
infrared, or similar.
[0017] According to another aspect of the present invention there
is provided a method for ventilating a defined space, the method
comprising the steps of acquiring temperature and relative humidity
within the defined space using at least one inside sensor,
acquiring temperature and relative humidity outside of the defined
space using at least one outside sensor, determining absolute
humidity within the defined space, determining absolute humidity
outside of the defined space, and operating a controllable fan if
the absolute humidity outside of the defined space is lower or
equal to the absolute humidity within the defined space, and the
temperature within the defined space is above a predetermined
temperature threshold when the temperature outside of the defined
space is below the temperature within the defined space. This
aspect of the invention provides similar advantages as discussed
above in relation to the previous aspect of the invention.
[0018] Further features of, and advantages with, the present
invention will become apparent when studying the appended claims
and the following description. The skilled addressee realize that
different features of the present invention may be combined to
create embodiments other than those described in the following,
without departing from the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The various aspects of the invention, including its
particular features and advantages, will be readily understood from
the following detailed description and the accompanying drawings,
in which:
[0020] FIG. 1 conceptually illustrates a currently preferred
embodiment of the system for ventilating a defined space; and
[0021] FIG. 2 shows a schematic flow chart of a currently preferred
method for ventilating a defined space.
DETAILED DESCRIPTION
[0022] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
currently preferred embodiments of the invention are shown. This
invention may, however, be embodied in many different forms and
should not be constructed as limited to the embodiments set forth
herein; rather, these embodiments are provided for thoroughness and
completeness, and fully convey the scope of the invention to the
skilled addressee. Like reference characters refer to like elements
throughout.
[0023] Referring now to the drawings and to FIG. 1 in particular,
there is depicted a system 100 for ventilating a defined space,
such as for example a crawlspace 102. The system 100 further
comprises an inside sensor 104, for example centrally arranged
within the crawlspace 102 and a first and a second outside sensor
106, 106' arranged on opposite sides 102.sub.a, 102.sub.b, outside
of the crawlspace 102, respectively. The inside 104 and the outside
sensors 106, 106' may be of the same type, or may be specifically
adapted based on their placement, e.g. having different
waterproofing/protection. Each of the sensors 104, 106, 106' is
further configured to measure temperature (T.sub.in/out) and
relative humidity (RH.sub.in/out) at their placement, respectively.
The sensors 104, 106, 106' may comprise a combination of elements
for sensing temperature and humidity, or may be combined into a
single element.
[0024] The system 100 also comprise a controllable fan 108 adapted
to ventilate the defined space. The fan 108 is preferably arranged
in vicinity of a ventilation opening V.sub.1 of the crawlspace 102
and configured to provide a ventilation rate for example depending
on the volume/area of the crawlspace 102, for example base on speed
control of the fan 108. The fan 108 may be operated in two
directions, i.e. to draw air from the outside of the defined area
102 into the defined area 102, or to expel air out from the defined
area 102. The selected direction may for example depend on the type
of defined area 102, where for example it may be preferred to expel
air out from a crawlspace, but rather draw air into an attic.
[0025] The system further comprises a control unit control unit 110
being connected to the inside and outside sensors 104, 106 and
106', and the fan 108. The connection between the sensors 104, 106
and 106', the fan 108 and the control unit 110 may be wired or
wireless (using for example Bluetooth, infrared, ZigBee, or
similar). The control unit 110 may include a microprocessor, a
microcontroller, a programmable digital signal processor or another
programmable device. The control unit 118 may also, or instead,
include an application specific integrated circuit (ASIC), a
programmable gate array programmable array logic, a programmable
logic device, or a digital signal processor. Where the control unit
110 includes a programmable device such as the microprocessor or
microcontroller mentioned above, the processor may further include
computer executable code that controls operation of the
programmable device.
[0026] The control unit 110 is further connected to an operator
accessable logger, such a memory 116 and configured to log data
from the sensors and/or operation periods and speed of the fan 108.
Optionally or alternatively, the control unit 110 may be provided
with a communication module 118 for providing the logged data to
e.g. a remote server (not shown).
[0027] Additionally, in FIG. 1 there are provided a plurality of
further ventilation openings V.sub.2, V.sub.3, V.sub.4 and V.sub.5,
where two ventilation openings are provided on each of the opposite
sides 102.sub.a, 102.sub.b of the crawlspace 102 and in conjunction
to the first and second outside sensors 106, 106'. The opposite
sides 102.sub.a, 102.sub.b of the crawlspace 102 may for example
represent the north and southern sides of a building where the
crawlspace 102 forms a foundation. Each, or at least some, of the
ventilation openings V.sub.2, V.sub.3, V.sub.4 and V.sub.5 may be
provided with valves 112 connected to and controllable by the
control unit 110. The valves 112 may be configured to be operated
individually of each other, and to be opened/closed at a plurality
of levels. Further (or fewer) ventilation openings, valves as well
as outside sensors may of course be provided, e.g. one outside
sensor per ventilation opening/ valve.
[0028] Some embodiments of the system 100 may additionally comprise
a dehumidifier 114 arranged within the crawlspace 102 and
controllable by the control unit 110, such as for example a
mechanical/refrigerative dehumidifier or a desiccant dehumidifier.
The type of dehumidifier 114 may for example depend on the expected
temperature within the defined space, where
mechanical/refrigerative dehumidifiers generally only operates well
above 12.degree. C. When using a dehumidifier 114, water generated
by the dehumidifier 114 may be arrange to be expelled out from the
crawlspace 102 for example using a pipe or hose (not shown).
Traditional drawbacks of using a dehumidifier 114 include a high
energy cost. By using the system 100 to complement the
dehumidifier, e.g. the dehumidifier only operates over a predefined
humidity threshold, the humidity threshold possibly being within
the range of 50-90%, preferably 60-80% and most preferably 65-75%,
it is possible to reduce the usage of the dehumidifier and thus
reduce the energy usage needed to keep the relative humidity at a
low level.
[0029] Turning now to FIG. 2 which provides a schematic flow chart
of a currently preferred method for operating the system 100 to
ventilate the crawlspace 102. The process starts in steps S1 and
S2, where the control unit 110 acquire temperature, T.sub.in/out,
and relative humidity, RH.sub.in/out, from within and outside of
the crawlspace 102 using the inside sensor 104 and outside sensors
106, 106'. Following the acquisition of the temperature,
T.sub.in/out, and relative humidity, RH.sub.in/out, in step S3 and
S4 the control unit 110 determines the absolute humidity
AH.sub.in/out for each of the sensors 104, 106 and 106', i.e. in
the embodiment shown in FIG. 1, inside of the crawlspace 102, on
the northern side 102.sub.a outside of the crawlspace 102 and on
the southern side 102.sub.b of the crawlspace 102. The control unit
110 may determine the respective absolute humidity, AH.sub.in/out,
for each of the sensors 104, 106, 106' using an approximate
calculation or using for example a Mollier diagram adapted for the
control unit 110.
[0030] Depending on the results of the determinations of the
absolute humidity, AH.sub.in/out, for each of the sensors 104, 106,
106', the controllable fan 102 may be operated, S5, to ventilate
the crawlspace 102. The general condition for ventilating the
crawlspace 102 is dependent on that the absolute humidity
AH.sub.out outside of the crawlspace 102 is lower than or equal to
the absolute humidity AH.sub.in within the crawlspace 102, and to
that the temperature T.sub.in within the crawlspace 102 is above a
predetermined temperature threshold when the temperature T.sub.out
outside of the crawlspace 102 is below the temperature T.sub.in
within the crawlspace 102.
[0031] In the preferred embodiment of the system 100 shown in FIG.
1 and provided with a crawlspace 102, the temperature threshold is
around 5-6.degree. C., and the condition on each side 102.sub.a,
102.sub.b outside of the crawlspace 102 is taken into account. That
is, during a cold but sunny day where sun is only shining on the
southern side 102.sub.b, the condition on the northern side
102.sub.a may be such that the general conditions outlined above
are not met, for example when averaging the conditions of the
northern and southern sides 102.sub.a, 102.sub.b. However, if only
taking into account the conditions of the southern side 102.sub.b,
the conditions for operating the fan 108 for ventilating the
crawlspace 102 may be met. Accordingly, in such a situation the
valves 112 arranged in with the ventilation openings V.sub.2,
V.sub.3 on the northern side 102.sub.a may be closed. Thereby, when
operating the fan 108, air will essentially only be drawn into the
crawlspace 102 through the ventilation openings V.sub.4, V.sub.5 on
the southern side 102.sub.b where the valves 112 are opened. Other
ways of operating the valves 112 and the fan 108 may of course
apply, i.e. where the valves 112 are individually operated such
that the crawlspace 112 is ventilated in the most favorable manner
but following the general conditions according to the
invention.
[0032] The acquisition, S1/S2, as well as the determination S3/S4
is preferably done periodically, for example every minute or hour.
Thereby the best possible ventilation may be provided for the
crawlspace 102. Additionally, essentially in parallel to steps
S1-S5, the control unit 110 may additionally be configured to
operate a step S6 where the values acquired from the sensors 104,
106, 106' as well as control speed/operating periods for the fan
108 may be logged.
[0033] Even though the invention has been described with reference
to specific exemplifying embodiments thereof, many different
alterations, modifications and the like will become apparent for
those skilled in the art. Variations to the disclosed embodiments
can be understood and effected by the skilled addressee in
practicing the claimed invention, from a study of the drawings, the
disclosure, and the appended claims. For example, in the above
description of the ventilation system a plurality of elements, e.g.
valves, dehumidifier, etc., have been included with the system.
However, the system need not to at the same time comprise all of
the above shown elements, but rather only some elements are
necessary to at least provide the basic features of the invention
as defined by the below claims.
[0034] Additionally, in some cases the conditions within the
crawlspace may be determined to be so unfavorable such that it is
necessary to active the dehumidifier, for example if the relative
humidity, RH, reaches 70-75% humidity. When doing so it may
generally be preferred to close all of the valves. Furthermore, in
case the fan is provided with a valve (not shown) also such a valve
may be closed.
[0035] Furthermore, in the claims, the word "comprising" does not
exclude other elements or steps, and the indefinite article "a" or
"an" does not exclude a plurality.
* * * * *