Demand ventilation module

• US 6,514,138 B2
• Filed: 01/09/2001
• Issued: 02/04/2003
• Est. Priority Date: 01/09/2001
• Status: Expired due to Fees

• Current Assignee: Kevin Estepp
• Original Assignee: Kevin Estepp
• Inventors: Estepp, Kevin
• Primary Examiner(s): Lu, Jiping
• Application Number:
  US09/756,890
• Publication Number:
  US 20020090908A1
• Time in Patent Office: 756 Days
• Field of Search: 454/229, 454/231, 454/233, 454/234, 454/236, 454/241
• US Class Current: 454/229
• CPC Class Codes: F24F 11/745 the air flow rate increasing with an increase of air-current or wind pressure
• CPC Class Codes: F24F 2011/0002 for admittance of outside air
• CPC Class Codes: F24F 2011/0006 using low temperature external supply air to assist cooling
• CPC Class Codes: F24F 2110/40 Pressure, e.g. wind pressure

Abstract

A demand ventilation module is provided for use with HVAC systems in order to ventilate inside space of a structure through an air pressure differential between return air and outside air. The demand ventilation module includes an integrated damper. The demand ventilation module can further include and an air restrictor plate that defines an air-restricting opening and an electronic control device capable of marking, setting, and/or storing air condition set-points for ventilation activation, and configured to facilitate ventilation control, economizer operation, and HVAC unit operation. The electronic control device is electrically connected to and controls the activation of an actuator in conjunction with inside and outside sensors that measure air conditions. The electronic control device can cause the actuator to automatically shift the damper in direct proportion to actual real-time air condition demands.

Claims

1. An apparatus for ventilating inside space of a structure comprising:

a demand ventilation module for use with a heating, ventilation, and air conditioning (HVAC) system comprising;

a housing adaptable to be coupled to a return portion of the HVAC system, the housing defining an inner chamber and comprising an air outlet and at least one outside air inlet;

an integrated damper located in the inner chamber for regulating outside air infiltration into the HVAC system and into the inside space by way of an air pressure differential between return air and the outside air in direct proportion to actual real-time air condition demand;

at least one restrictor plate in conjunction with the air outlet protruding into the inner chamber, the at least one air restrictor plate defining an air-restricting opening along a first stage of a damper stroke range, the air-restricting opening controlling outside air flow and requiring the damper to move further to allow the same volume of air to enter the HVAC system than would otherwise be necessary, thereby resulting in more accurate control of the damper under low air velocity conditions; and

a damper seal along an outside perimeter of the damper that seals against the inner chamber and the at least one restrictor plate, thereby improving controllability of air flow through the first stage and a second stage of the damper stroke range.

2. The apparatus of claim 1 further comprising:

an actuator for automatically shifting the damper, upon receiving an appropriate stimulus, to any position in a damper stroke range between a minimum airflow position and a maximum airflow position and in direct proportion to actual real-time air condition demand;

at least one outside sensor capable of measuring outside air conditions and for transmitting respective stimulus dependent thereon;

at least one inside sensor capable of measuring inside air conditions and for transmitting respective stimulus dependent thereon; and

an electronic control device capable of setting and storing at least one pre-set minimum absolute air condition set-point for ventilation activation, the electronic control device electrically connected to the actuator for controlling the activation thereof, the electronic control device also electrically connected to the at least one outside sensor for controlling the activation thereof and receiving stimulus therefrom, and the electronic control device also electrically connected to the at least one inside sensor for controlling the activation thereof and receiving stimulus therefrom.

3. The apparatus of claim 2, wherein the electronic control device further at least controls

HVAC fan control function, and wherein

the electronic control device activates an HVAC fan and the actuator to cause the transport of outside air into the inside space, thereby allowing the inside air conditions to be equilibrated with the outside air conditions;

whereupon

the electronic control device causes the at least one inside sensor to sense the inside equilibrated air conditions and to transmit to the electronic control device air condition stimulus dependent thereon, wherein the electronic control device sets and stores the at least one air condition set-point for ventilation activation;

whereupon

the electronic control device causes the at least one inside sensor to sense the inside air conditions and to transmit to the electronic control device respective air condition stimulus dependent thereon;

whereupon

the electronic control device compares the at least one air condition set-point for ventilation activation to an applicable sensed inside air condition; and

whereupon

if the sensed inside air condition is greater than the at least one air condition set-point, the electronic control device activates the actuator to cause the transport of outside air into the inside space, thereby diluting inside air conditions and maintaining the inside space at the at least one air condition set-point.

4. The apparatus of claim 3, wherein the at least one inside sensor is capable of measuring at least one contaminant level and temperature and for transmitting respective stimulus dependent thereon, wherein the electronic control device is capable of setting and storing at least one pre-set minimum absolute contaminant level set-point for ventilation activation and/or a pre-set minimum absolute temperature set-point for ventilation activation, and wherein

the electronic control device activates an HVAC fan and the actuator to cause the transport of outside air into the inside space, thereby allowing the inside air conditions to be equilibrated with the outside air conditions;

whereupon

the electronic control device causes the at least one inside sensor to sense the equilibrated contaminant level and/or the equilibrated temperature of inside space air and to transmit to the electronic control device contaminant level stimulus and/or temperature stimulus dependent thereon, wherein the electronic control device sets and stores the at least one contaminant level set-point and/or the temperature set-point for ventilation activation;

whereupon

the electronic control device causes the at least one inside sensor to sense the inside contaminant level and/or the inside temperature and to transmit to the electronic control device contaminant level and/or temperature stimulus dependent thereon;

whereupon

the electronic control device compares the sensed inside contaminant level and/or the sensed inside temperature to the at least one contaminant level set-point and/or the temperature set-point for ventilation activation; and

whereupon

if the sensed contaminant level and/or the sensed temperature is greater than the at least one contaminant level set-point and/or the temperature set-point, the electronic control device activates the actuator to cause the transport of outside air into the inside space, thereby diluting inside air conditions and maintaining the inside space at the at least one contaminant level set-point and/or the temperature set-point.

5. The apparatus of claim 2, wherein the at least one inside sensor comprises a dual CO₂ and temperature sensor.

6. The apparatus of claim 2, wherein the electronic control device further controls HVAC system control functions, and wherein

the electronic control device causes the at least one outside sensor and the at least one inside sensor to sense the respective inside air conditions and outside air conditions and to transmit to the electronic control device respective air condition stimulus dependent thereon;

whereupon

the electronic control device determines the absolute air condition differential between the respective sensed air conditions and compares the differential to the at least one air condition set-point for ventilation activation; and

whereupon

if the differential is greater than the at least one air condition set-point, the electronic control device activates the actuator to cause the transport of outside air into the inside space, thereby diluting inside air conditions and maintaining the inside space at the at least one air condition set-point.

7. The apparatus of claim 6, wherein the at least one outside sensor is capable of measuring at least one contaminant level and temperature and for transmitting respective stimulus dependent thereon, the at least one inside sensor is capable of measuring at least one contaminant level and temperature and for transmitting respective stimulus dependent thereon, wherein the electronic control device is capable of setting and storing at least one pre-set minimum absolute contaminant level set-point for ventilation activation and/or a pre-set minimum absolute temperature set-point for ventilation activation, and wherein

the electronic control device causes the at least one outside sensor and the at least one inside sensor to sense respective contaminant levels and/or temperatures of inside space air and of outside space air and to transmit to the electronic control device respective contaminant level stimulus and/or temperature stimulus dependent thereon;

whereupon

the electronic control device determines the absolute contaminant level differential between the respective absolute contaminant levels and compares the differential to the absolute contaminant level set-point for ventilation activation, and/or the electronic control device determines the absolute temperature differential between the respective absolute temperatures and compares the differential to the absolute temperature set-point for ventilation activation; and

whereupon

if the contaminant level differential is greater than the contaminant level set-point, the electronic control device activates the actuator to cause the transport of outside air into the inside space, thereby diluting inside air conditions and maintaining the inside space at the contaminant level set-point, and/or if the temperature differential is greater than the temperature set-point, the electronic control device activates the actuator to cause the transport of outside air into the inside space, thereby diluting inside air conditions and maintaining the inside space at the temperature set-point.

8. The apparatus of claim 1, wherein the return portion of the HVAC system comprises a return air duct and a return portion of an HVAC unit, and wherein the housing further comprises:

a front wall adjacent to and adaptable to be coupled to the return duct or the return portion of the HVAC unit, the front wall comprising the air outlet;

a rear wall comprising a vertical outside air inlet in conjunction with a vertical outside air filter, and an inlet hood;

a right side wall, including a bushing therethrough adaptable to receive a right end of a damper shaft, and a left side wall, including a bushing therethrough adaptable to receive a left end of the damper shaft, wherein the damper shaft is retained by the bushings, and wherein a damper is coupled to the damper shaft; and

a top wall and a bottom wall, the bottom wall comprising a horizontal outside air inlet in conjunction with a horizontal outside air filter.

9. The apparatus of claim 8, wherein the damper seal seals against the right wall, the left wall, the top wall, and the at least one restrictor plate.

10. The apparatus of claim 8 further comprising:

an actuator for automatically shifting the damper, upon receiving an appropriate stimulus, to any position in a damper stroke range between a minimum airflow position and a maximum airflow position and in direct proportion to actual real-time air condition demand;

at least one outside sensor capable of measuring outside air conditions and for transmitting respective stimulus dependent thereon;

at least one inside sensor capable of measuring inside air conditions and for transmitting respective stimulus dependent thereon; and

an electronic control device capable of setting and storing at least one pre-set minimum absolute air condition set-point for ventilation activation, the electronic control device electrically connected to the actuator for controlling the activation thereof, the electronic control device also electrically connected to the at least one outside sensor for controlling the activation thereof and receiving stimulus therefrom, and the electronic control device also electrically connected to the at least one inside sensor for controlling the activation thereof and receiving stimulus therefrom; and

wherein a removable control cabinet cover and an underlying control cabinet form a portion of the right or the left side wall, wherein the electronic control device and the actuator are located in the underlying control cabinet, and wherein the outside air sensor is mounted through the underlying cabinet, thereby protruding into the inner chamber.

11. The apparatus of claim 10, wherein the electronic control device further at least controls HVAC fan control function, and wherein

the electronic control device activates an HVAC fan and the actuator to cause the transport of outside air into the inside space, thereby allowing the inside air conditions to be equilibrated with the outside air conditions;

whereupon

the electronic control device causes the at least one inside sensor to sense the inside equilibrated air conditions and to transmit to the electronic control device air condition stimulus dependent thereon, wherein the electronic control device sets and stores the at least one air condition set-point for ventilation activation;

whereupon

the electronic control device causes the at least one inside sensor to sense the inside air conditions and to transmit to the electronic control device respective air condition stimulus dependent thereon;

whereupon

the electronic control device compares the at least one air condition set-point for ventilation activation to an applicable sensed inside air condition; and

whereupon

if the sensed inside air condition is greater than the at least one air condition set-point, the electronic control device activates the actuator to cause the transport of outside air into the inside space, thereby diluting inside air conditions and maintaining the inside space at the at least one air condition set-point.

12. The apparatus of claim 10, wherein the electronic control device further controls HVAC system control functions, and wherein

the electronic control device causes the at least one outside sensor and the at least one inside sensor to sense the respective inside air conditions and outside air conditions and to transmit to the electronic control device respective air condition stimulus dependent thereon;

whereupon

the electronic control device determines the absolute air condition differential between the respective sensed air conditions and compares the differential to the at least one air condition set-point for ventilation activation; and

whereupon

if the differential is greater than the at least one air condition set-point, the electronic control device activates the actuator to cause the transport of outside air into the inside space, thereby diluting inside air conditions and maintaining the inside space at the at least one air condition set-point.

13. The apparatus of claim 1, wherein the return portion of the HVAC system comprises a return air duct and a return portion of an inside air handler, and wherein the housing further comprises:

a front wall adjacent to and adaptable to be coupled to a downstream side of an outside air duct, the return air duct, or the return portion of the inside air handler, the front wall comprising the air outlet;

a rear wall adjacent to and adaptable to be coupled to the outside air duct, the rear wall comprising a vertical outside air inlet in conjunction with a vertical outside air filter;

a right side wall, including a bushing therethrough adaptable to receive a right end of a damper shaft, and a left side wall, including a bushing therethrough adaptable to receive a left end of the damper shaft, wherein the damper shaft is retained by the bushings, and wherein the damper is coupled to the damper shaft; and

a top wall and a bottom wall.

14. The apparatus of claim 13, wherein the damper seal seals against the right wall, the left wall, the top wall, and the at least one restrictor plate.

15. The apparatus of claim 13 further comprising:

an actuator for automatically shifting the damper, upon receiving an appropriate stimulus, to any position in a damper stroke range between a minimum airflow position and a maximum airflow position and in direct proportion to actual real-time air condition demand;

at least one outside sensor capable of measuring outside air conditions and for transmitting respective stimulus dependent thereon;

at least one inside sensor capable of measuring inside air conditions and for transmitting respective stimulus dependent thereon; and

an electronic control device capable of setting and storing at least one pre-set minimum absolute air condition set-point for ventilation activation, the electronic control device electrically connected to the actuator for controlling the activation thereof, the electronic control device also electrically connected to the at least one outside sensor for controlling the activation thereof and receiving stimulus therefrom, and the electronic control device also electrically connected to the at least one inside sensor for controlling the activation thereof and receiving stimulus therefrom; and

wherein a removable control cabinet cover and an underlying control cabinet form a portion of the right or the left side wall, wherein the electronic control device and the actuator are located in the underlying control cabinet, and wherein the outside air sensor is mounted through the underlying cabinet, thereby protruding into the inner chamber.

16. The apparatus of claim 15, wherein the electronic control device further at least controls HVAC fan control function, and wherein

the electronic control device activates an HVAC fan and the actuator to cause the transport of outside air into the inside space, thereby allowing the inside air conditions to be equilibrated with the outside air conditions;

whereupon

the electronic control device causes the at least one inside sensor to sense the inside equilibrated air conditions and to transmit to the electronic control device air condition stimulus dependent thereon, wherein the electronic control device sets and stores the at least one air condition set-point for ventilation activation;

whereupon

the electronic control device causes the at least one inside sensor to sense the inside air conditions and to transmit to the electronic control device respective air condition stimulus dependent thereon;

whereupon

the electronic control device compares the at least one air condition set-point for ventilation activation to an applicable sensed inside air condition; and

whereupon

if the sensed inside air condition is greater than the at least one air condition set-point, the electronic control device activates the actuator to cause the transport of outside air into the inside space, thereby diluting inside air conditions and maintaining the inside space at the at least one air condition set-point.

17. The apparatus of claim 15, wherein the electronic control device further controls HVAC system control functions, and wherein

the electronic control device causes the at least one outside sensor and the at least one inside sensor to sense the respective inside air conditions and outside air conditions and to transmit to the electronic control device respective air condition stimulus dependent thereon;

whereupon

the electronic control device determines the absolute air condition differential between the respective sensed air conditions and compares the differential to the at least one air condition set-point for ventilation activation; and

whereupon

if the differential is greater than the at least one air condition set-point, the electronic control device activates the actuator to cause the transport of outside air into the inside space, thereby diluting inside air conditions and maintaining the inside space at the at least one air condition set-point.