US20090156115A1

US20090156115A1 - Method And System For Ventilating A Space

Info

Publication number: US20090156115A1
Application number: US11/955,799
Authority: US
Inventors: Rejean P. MIRON
Original assignee: RR ADVANCED ENERGY SYSTEMS Ltd
Current assignee: RR ADVANCED ENERGY SYSTEMS Ltd
Priority date: 2007-12-13
Filing date: 2007-12-13
Publication date: 2009-06-18

Abstract

A ventilation system is disclosed for a space comprising a first ducting means for ducting fresh air from outside to inside the space and a second ducting means for ducting stale air from inside to outside the space. The modular system of the present invention also includes an ultra-high efficiency heat recovery double pass exchanger unit and is provided with a separate motor box for better sound isolation.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A “SEQUENCE LISTING”

Not applicable.

FIELD OF INVENTION

This invention relates generally to the field of ventilation system for buildings and more specifically, it concerns a ventilation system for an enclosure such as an air tight classroom, adapted to recycle, control and reduce the pollutant content of stale air.

BACKGROUND OF THE INVENTION

Management of the harmful pollutants present in a variety of forms and concentrations is traditionally carried out by the simple elimination of a volume of returned air and the intake of an equivalent amount of fresh air from the outside.
Closed spaces, buildings environments are installations wherein equipment and environmental control for occupants is assured only by a ventilation system.
The maintenance of air quality to ensure human respiration and activity can only be assured by the control and elimination of pollutants.
In addition, high energy operation costs, failing rooftop units and noisy mechanical systems are common problems characterizing the prior art systems.
To date, controlling indoor environmental characteristics such as fresh air levels has required the use of multiple devices which is undesirable and not adapted to the need of a space of restricted size.
Currently, ventilation systems have been limited to two approaches; one being vertical mount units and the other being rooftop units.
Vertical mount units are Energy Recovery Ventilators (ERV). They are installed on an outside wall and take up a significant amount of space within a space such as a classroom. They produce noise well above the ANSI standard S12.02-2002 of 35 decibels (dB). Vertical mount units also shut down at −6° C., which means ASHRAE 90's requirement of 15 CFM of fresh air per occupant in a classroom is also not being met when such outside temperatures are in effect.
Rooftop units have their share of problems as well. They are very costly to install and provide ventilation for about 10 to 15 classrooms. They provide uneven air distribution to classrooms since those within close range of the unit may have an excess of incoming fresh air, whereas classrooms located further from the unit may experience a serious lack of incoming fresh air. Also, noise levels at the diffusers tend to be high. They are very difficult to balance (incoming and outgoing air streams) often causing negative or positive pressure within the building. Due to their lack of heat recovery, they require costly in-line duct heaters, which drastically increase yearly energy costs. They also shut down at −5° C., once again not meeting ASHRAE 90's 15 CFM per occupant requirement.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a ventilation system and a method thereof that satisfy the fresh and quality air requirements of a space of restricted size on an individual basis.
In accordance with the present invention, that object is achieved with a ventilation system for a space such as a classroom said system comprising a first ducting means for ducting fresh air from the outside to the inside of the space and a second ducting means for ducting stale air from the inside to outside the space said second ducting means comprising a stale air inlet for receiving stale air containing pollutants from inside the space and exhaust means to exhaust said stale air said exhaust means being in fluid communication with the first ducting means in order to ensure an equivalent volume of clean air is returned to the space. The system further comprises an ultra-high efficiency heat recovery double pass exchanger unit and is provided with a separate motor box in order to ensure low noise levels.
It is a further object of the present invention to provide a ventilation system for a space such as a classroom, comprising: a first ducting means for ducting fresh air from the outside to the inside of the space; a second ducting means for ducting stale air from the inside to the outside of the space said second ducting means comprising a stale air inlet for receiving stale air containing pollutants from inside the space; exhaust means to exhaust said stale air said exhaust means being in fluid communication with the first ducting means to return an equivalent volume of clean air to the space; an ultra high efficiency heat recovery double pass exchanger unit; a motor box separated from said system; and a cooling unit, wherein said system is adapted to efficiently control the air quality of said space on an individual basis at temperatures varying between +40° C. to −40° C.
It is thus an object of the present invention to remove pollutants from the air in the space by ensuring an efficient air transfer between the inside and the outside thereby reducing the power consumption of the ventilation system and minimizing system failures and poor cold weather performance.
The invention also proposes a method for ventilating a space said method comprising the steps of ducting fresh air from outside to inside, ducting stale air containing pollutants from inside to outside the space and circulating said air through an ultra-high efficiency heat recovery double pass exchanger unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a ventilation system according to the invention showing a typical classroom installation;

FIG. 2 is a detailed schematic view of Section ‘A’ of FIG. 1;

FIGS. 3( a),(b) and (c) illustrates the system of the present invention in further details; and

FIGS. 4 is a graphical illustration of the stale/fresh air ratios.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A ventilation system 10 according to the present invention is particularly useful for use in a space like a classroom 11 in which a number of people gather together for a period of time.
Referring to FIGS. 1, 2, 3 and 4, the ventilation system 10 of the present invention comprises a first duct system 12 for ducting fresh air from outside to inside the space of classroom 11 and a second duct system 13 for ducting stale air from inside to outside of the space 11. The second duct system 13 comprises a stale air inlet 14 for receiving/capturing the air containing the pollutants, such as pollen, smog, smoke, CO₂, mold or VOC, and exhaust means to exhaust the stale air. It should be noted that the system 10 of the present invention provides also for outdoor pollutant control such as pollen, smoke or smog in that the ducting system 12 will filter these elements before introducing the fresh air to the space 11. The exhaust means are in fluid communication with the first ducting means 12 in order to ensure a supply of clean air is then reciprocally returned to the space 11.
The ventilation system 10 of the present invention is further comprised of an ultra-high efficiency heat recovery double pass exchanger unit and with a separate motor box 15 in order to ensure low noise levels when the system 10 is functioning.
The system 10 is further equipped with a cooling unit 16 to reduce summer temperatures and ensure the comfort of the space's occupants, typically for temperatures up to +40□C.
The system 10 of the present invention is characterized by its ease of use in a small space environment thereby permitting a more individual control of each space, resulting in lower energy costs and avoiding the risk of total failure of the system when compared to single rooftop units.
Since the system 10 of the present invention allows for a more customized installation, it follows that lower capital outlays will be required and that lower energy costs will result.
As a result of the design of system 10, continuous operation down to −40° C. is possible, with the use of a heat recovery ventilator, an average of 40 dB at any point in the space 11 is achieved, going up to 45 dB at most when the a/c fan is running at high speed, and meeting the ASHRAE standard of 15 CFM per occupant with a 400 CFM unit is possible.
It is a space efficient horizontal ceiling-mount design resulting in an affordable solution, extremely low operational costs, easy maintenance and highly improved air quality of the space 11.
In operation, the ventilation system 10 of the present invention provides for the ducting of fresh air from outside to inside the space 11 reciprocally working in an exchanger fashion with a second ducting of stale air from inside to outside the same space 11. An ultra-high efficiency heat recovery double pass exchanger unit is also functional working alongside a cooling unit to ensure temperature control.
It follows that noise levels are well under control and that the ASHRAE standard is met thereby ensuring that the space occupants are comfortable.
While a particular embodiment of the present method and system for ventilating a space has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.

Claims

1. A ventilation system for a space such as a classroom, comprising:

a first ducting means for ducting fresh air from the outside to the inside of the space;

a second ducting means for ducting stale air from the inside to the outside of the space said second ducting means comprising a stale air inlet for receiving stale air containing pollutants from inside the space;

exhaust means to exhaust said stale air said exhaust means being in fluid communication with the first ducting means to return an equivalent volume of clean air to the space.

2. The system of claim 1 further comprising an ultra high efficiency heat recovery double pass exchanger unit.

3. The system of claim 1 further comprising a motor box separated from the system.

4. The system of claim 1 further comprising a cooling unit.

5. A ventilation system for a space such as a classroom, comprising:

exhaust means to exhaust said stale air said exhaust means being in fluid communication with the first ducting means to return an equivalent volume of clean air to the space;

an ultra high efficiency heat recovery double pass exchanger unit;

a motor box separated from said system; and

a cooling unit, wherein said system is adapted to efficiently control the air quality of said space on an individual basis at temperatures varying between +40° C. to −40° C.

6. A method for ventilating a space said method comprising the steps of ducting fresh air from outside to inside, ducting stale air containing pollutants from inside to outside the space and circulating said air through an ultra-high efficiency heat recovery double pass exchanger unit.