Temperature Controller for Unit

Abstract

A temperature controller for a positive pressure room air purification unit is provided with a sensor for ambient room air temperature and supply duct air temperature. Based on the desired temperature, supply duct air may be drawn or drawn and heated.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is a temperature controller for a positive pressure air purification unit and, more specifically, a temperature controller using two temperature sensors for a positive pressure air purification unit.

2. Related Art

The prior art for room air purification in a residential home uses a single air temperature controller and a single temperature sensor.

SUMMARY OF THE INVENTION

The invention is a temperature controller that uses two sensors for controlling temperature in a room. The temperature controller is disposed in a positive pressure room air purification unit that is connected to a supply duct of a duct system of a standard residential HVAC duct system. The first temperature sensor senses ambient room air temperature. The second temperature sensor senses the air temperature of the air from a supply duct of a standard residential HVAC duct system. Based on the desired room air temperature, and the supply duct air temperature, the temperature controller determines whether to draw supply duct air, or both room air and supply duct air and further determines the fan speed setting of the purification unit, and whether to heat the air.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a flow chart that illustrates the operation of the temperature controller of the present invention.

FIG. 2 is an elevated view of the present invention incorporating the temperature controller.

FIG. 3. illustrates a side section view taken along line 3-3 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

In FIG. 1, the operation of the temperature controller 10 of the present invention is provided. The normal operating environment for the temperature controller 10 is a positive pressure room air purification unit as shown generally at 12 in FIGS. 2 and 3. The room air purification unit 12 is connected to a supply duct 110 of a standard residential HVAC system. Initially, the temperature controller 10 determines whether it is functioning normally 14, whether the fan 49 is functioning normally 49A, whether the mom air temperature sensor 22 is functioning normally 22A (and then collects room air temperature information 20 via a temperature sensor 22 (See FIG. 3) located on the exterior of the room air purification unit 12) and whether the supply duct air temperature sensor 40 is functioning normally 40A.

The temperature controller 10 is provided with a user interface for setting a desired room air temperature. Then, the temperature controller 10 determines whether the room air temperature is higher 30 or lower 32 than a calculated temperature which is based on a desired temperature and a dead band range. In addition, the temperature controller 10 determines whether the supply duct air temperature is higher 41 or lower 42 than the room air temperature.

If the room air temperature is higher than desired, then the cooling mode shown by the dotted lines in FIG. 1 applies. In this case, if the supply duct air temperature via sensor 40 is cooler than the ambient air temperature 22, 42, the fan output speed is initiated (54 or 58) and the damper 102 is open 50 thereby closing the room air inlet. If the supply duct air temperature is higher than the ambient room air temperature, then the damper 102 is set in the partially closed position 52, and fan output speed is set 60.

If the room air temperature is lower than desired, then the heating mode shown the dotted line column in FIG. 1 applies. In this case, if the supply duct air temperature via sensor 40, is higher than the ambient room air temperature via sensor 22, then according to FIG. 1, at diamond 41, damper 102 is open 50, and fan output speed is set 56 or 58. If the supply duct air temperature via sensor 40 is lower than the ambient room air temperature 22, 41, then damper 102 is placed in the partially closed position 52, and fan output speed is set 60.

Based upon the desired temperature, a temperature range, and the room air temperature and the supply duct temperature, the temperature controller determines as shown in FIG. 1 whether the room air damper disposed with, which is infinitely movable between an open 50 and a nearly closed 52 position, will be partially closed 52, or open 50, and whether to adjust the user-input minimum fan speed 60. The fan draws air from the through the supply duct and possibly through the room air damper through the positive pressure room air purification unit. After making the determination, the temperature controller operates to move the room air damper 50, 52 and operates to adjust the user-input fan speed 60, or user-input maximum fan speed 58, or the automatic fan speed 54, 56, 58 (which may override the user-input minimum fan speed 60), so that the desired room air temperature may be achieved.

It should be appreciated that fan speed settings 54, 56 and 58 (FIG. 1) are applied only when the supply duct inlet 112 is open via an open position 50 of room air damper 102.

As seen in FIG. 1, there is a negatively-weighted ambient temperature at 32 and a positively-weighted ambient temperature at 30. Negatively-weighted ambient temperature 32 is any ambient temperature that is less than or equal to a user-set desired temperature from which half of a deadband range temperature has been subtracted. Positively-weighted ambient temperature 30 is any ambient temperature that is greater than or equal to a user-set desired temperature to which half of a deadband range temperature has been added. Because the deadband range has a default setting of four degrees the default negatively-weighted ambient temperature 32 is any ambient temperature that is two degrees or less than a user-set desired temperature. Similarly, the default positively-weighted ambient temperature 30 is any ambient temperature that is two degrees or more than a user-set desired temperature. While the default deadband range is four degrees, this range may be re-set to a larger or smaller range by the user through user input.

The use of negatively-weighted ambient temperature 32 and positively-weighted ambient temperature 30 allows the user to potentially favor more constant fan speed over temperature fluctuation, rather than constant temperature over fan speed.

If the desired temperature is higher than the ambient room air temperature and supply duct air temperature, the auxiliary heater will be turned on 44 by temperature controller 10.

If the desired temperature is lower than the ambient room air temperature, and the supply duct air temperature is lower than ambient room air temperature, the temperature controller 10 will open 50 room air damper 102 and the fan speed will be set automatically 54, 56, if the unit is in “automatic mode,” (48) or the fan speed will be set according to command block 58 if the unit is not in “automatic mode.” In other words, temperature controller 10 will ignore any user-input fan speed setting when said temperature controller system 10 is in automatic mode 48. With respect to fan speed settings 54, 56, it is important to point out that the fan speed settings are based on weighted set points. Specifically, with respect to fan speed settings 56, the high fan speed setting will be engaged only when the ambient temperature is greater than a high-weighted set point equal to 3 degrees over the user-set desired temperature; the medium fan speed setting will be engaged only when the ambient temperature is greater than a medium-weighted set point equal to 2 degrees over the user-set desired temperature; the low fan speed setting will be engaged only when the ambient temperature is greater than a low-weighted set point equal to 1 degree over the user-set desired temperature. Specifically, with respect to fan speed settings 54, the high fan speed setting will be engaged only when the ambient temperature is less than a low weighted set point equal to 3 degrees under the user-set desired temperature; the medium fan speed setting will be engaged only when the ambient temperature is less than a medium-weighted set-point equal to 2 degrees under the user-set desired temperature; the low fan speed setting will be engaged only when the ambient temperature is less than a low-weighted set-point equal to 1 degree under the user-set desired temperature. The 3 degree, 2 degree and 1 degree set point weightings are default settings and these amount of weighting may be changed by user input.

In order to maintain positive pressure within the room, it will be appreciated that supply duct air at all times will be drawn by the positive pressure room air purification unit into the same room in which the positive pressure air purification unit 12 is located. This is because the partially closed position 52 of damper 102 always allows some volume of air to pass from supply duct 110 through supply duct inlet 112 and through outlet 46. Ideally, the positive pressure room air purification unit will be equipped with a filtration system that will allow only purified air to pass through and exhaust into the room.

It should be appreciated that in case of component malfunction 14, 22A, 40A, 49A, the fan output may be manually set 60, but the damper 102 will remain in the default open 50 position.

As shown in FIGS. 2 and 3, an HVAC floor supply duct 110 is in communication with a bottom chamber of temperature controller system unit 10. The temperature of the air from HVAC floor supply duct 110 entering supply duct inlet 112 is taken by sensor 40.

In an alternative embodiment, supply duct 110 may physically enter supply duct inlet 112 not from the floor, but from the wall or ceiling, depending on the physical location of the supply duct within the room. In this case, as seen in FIG. 3, there is a plate 114 having a width 114W which may be removed to provide a perpendicular, second direction of entry from which a volume of air may be admitted through supply duct inlet 112. If plate 114 is removed and used for introducing air into supply duct inlet 112, then plate 114 may be re-used by connecting it into the bottom of positive pressure air purification unit 12 thereby covering and preventing HVAC supply duct 110 from supplying air from the floor HVAC duct 110. Alternatively, a different plate (not shown) other than plate 114 and having different dimensions from plate 114 may be used to prevent HVAC supply duct 110 from supplying air from the floor. Because the positive pressure air purification unit 12 may be also mounted to a ceiling to provide inlet 112 access to a ceiling supply duct (not shown), it is important to note that regardless of the plate 114 itself, positive pressure air purification unit is adapted to provide a single inlet 112 for one of two perpendicular air flow paths (floor or wall).

A room air inlet is shown at 108. The temperature of the room air (ambient air) is sensed by room air temperature sensor 22.

Damper 102 is controlled by damper motor 106 and spring 104. It should be appreciated that spring 104 may be either internal to damper motor 106 (not shown) or external to damper motor 106 as shown in FIG. 3.

In either configuration, upon a loss of power to damper motor 106, spring 104 biases damper 102 to an open position 50. This open position 50 prevents any accumulated foreign materials from falling from the face of the filter into the room. Similarly, in the event of malfunction, the display shows an error 50A (See FIG. 1), and any error 50A results in the damper's 102 moving to open position 50.

When powered, damper motor 106 moves damper 102 from the open position 50 to an infinite number of positions between open position 50 and (nearly completely closed position) or partially closed position 52. Nearly completely closed (or partially closed position) 52 does not allow damper 102 to completely prevent air from HVAC floor supply duct 110, but always allows some air from the HVAC floor supply duct 110 to be drawn to generate positive pressure within the room. Damper motor 106 may be a standard type AC motor, or may be a stepper motor. With any type of damper motor 106, the motor will be adapted to stop at position 52 such that damper 102 does not completely prevent air from HVAC supply duct 110 from entering the unit 12 via supply duct inlet 112. In addition, preferred embodiment shows the two bar linkage 116 between damper 102 and damper motor 106 physically prevents damper 106 from completely closing air flow from HVAC supply duct 110. Therefore, position 52 has a mechanically-enforced limit separate and independent from the spring 104 bias that may be already incorporated into damper motor 106. Because the mechanically enforced limits 104,116 are each independently sufficient to position damper 102 in a nearly closed position 52, it should be understood that the present invention will function perfectly with only one of these mechanically-enforced limits. As stated above with respect to the description of FIG. 1, based on how the user selects room size, the damper motor 106 varies the size of the opening of (and thus the mass flow rate of air from) the supply duct air.

Air passes over heating elements 44A, which may be “on” or “off” depending on the decision by the system controller 10 in FIG. 1.

It is very important to understand that the combined mass flow rate of air entering through supply duct 110 and room air inlet 108 is equal to the mass flow rate of air passing heating elements 44A and exiting unit 12 via outlet 46. Thus, positive pressure is generated by the present invention in the same room in which the entire invention is located, but due to equal mass flow rates in and out, there is no net positive pressure within the unit of the present invention itself.

As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.

Claims

1. A temperature controller system for a positive pressure air purification unit comprising: a positive pressure air purification unit disposed within a room, having a first inlet in fluid communication with an HVAC supply duct, a second inlet in fluid communication with ambient air within a room, a filter for filtering air, an outlet, and a fan having a plurality of speed settings disposed between said filter and said outlet for drawing air from at least said first inlet;a first temperature sensor disposed on an exterior surface of said positive pressure air purification unit adapted to sense ambient room air temperature;a second temperature sensor disposed within said positive pressure air purification unit adapted to sense supply duct air temperature of an HVAC duct system;a room air damper infinitely movable between an open and a partially closed position to allow air from the supply duct to be drawn and positionally controlled by said temperature controller system, said room air damper being incapable of fully closing the supply duct;a user input interface for inputting a desired temperature; andwherein said room air damper is moved by said temperature controller between said open position and said partially closed position, such that some volume of air is always drawn from said HVAC supply duct by said positive pressure air purification unit to create a positive pressure in the room in which said positive pressure air purification unit is disposed.

2. The temperature controller system according to claim 1, wherein when said room air damper is in an open position, air is drawn only from said first air inlet and no air is drawn from said second air inlet, andwherein when said room air damper is in a partially closed position air is drawn from said second air inlet and a much smaller volume of air is drawn from said first air inlet, such that a volume of air is always drawn from said first air inlet, said room air damper being capable of assuming any position between said open position and said partially closed position.

3. The temperature controller system according to claim 2, wherein said room air damper will be moved to an open position when said supply duct air temperature is less than ambient room air temperature and said input desired temperature is less than ambient room air temperature; andwherein said room air damper will be moved to an open position when said supply duct air temperature is greater than said ambient room air temperature and said input desired temperature is greater than ambient room air temperature.

4. The temperature controller system according to claim 2, wherein said room air damper will be moved to an open position when said supply duct air temperature is less than ambient room air temperature and said input desired temperature is less than or equal to a positively-weighted ambient room air temperature; and wherein said room air damper will be moved to a partially closed position when a negatively-weighted ambient temperature is less than or equal to the input desired temperature and said supply duct air temperature is less than said ambient room air temperature.

5. The temperature controller system according to claim 2, wherein said room air damper will be moved to an open position when said supply duct air temperature is greater than ambient room air temperature and said input desired temperature is greater than or equal to a negatively-weighted ambient room air temperature; and wherein said room air damper will be moved to a partially closed position when a positively-weighted ambient temperature is greater than or equal to the input desired temperature said supply duct air temperature is greater than said ambient room air temperature.

6. The temperature controller system according to claim 1, wherein said user input interface further comprises an input for setting a desired fan speed.

7. The temperature controller system according to claim 6, wherein said temperature controller system ignores said user-input set fan speed when said controller system is in automatic mode.

8. The temperature controller system according to claim 1, wherein said room air damper is biased to assume an open position upon the occurrence of one of the following events selected from the following group: loss of power, malfunction of said first temperature sensor, malfunction of said second temperature sensor, malfunction of said controller system, and malfunction of said fan.

9. The temperature controller system according to claim 1, wherein said positive pressure air purification unit further comprises: a plate attached to one of two perpendicular air flow paths, blocking fluid communication between a supply duct and said positive pressure air purification unit;wherein said first inlet allows fluid communication between one of two perpendicular air flow paths and said damper.