Air conditioner case with condensation shield

Disclosed is a housing for enclosing the expansion coil assembly and blower fans for an air conditioning system. The housing employs a shield or false floor which defines a cavity below the coil assembly to permit condensed moisture to collect and drain from the housing without becoming entrained in the flow of air through the coil assembly. The shield also includes adjustable tabs for positioning various sizes of coil assemblies on the top surface of the shield.

This invention relates to air conditioning systems. More particularly, it 
relates to air conditioner cases, housings and the like for enclosing the 
expansion coil assembly of an air conditioner including a shield or false 
floor for aiding in the removal of condensation from the cooling coil 
housing. 
Although compact air conditioning equipment for vehicles such as trucks, 
automobiles and the like has been widely used and accepted for many years, 
many passenger vehicles are manufactured without air conditioning 
equipment. Various reasons exist for failing to include air conditioning 
equipment in modern vehicles. For example, it is an unnecessary expense to 
include such equipment in vehicles used in climates where air conditioning 
is not required. Furthermore, many users prefer to purchase vehicles 
without air conditioning equipment and later install the equipment, 
thereby lowering the initial investment in the vehicle. For these and 
various other reasons a substantial market exists for "add on" or "after 
market" air conditioning equipment which may be installed after delivery 
of the vehicle to the purchaser. 
In the interest of conserving space, expense and asthetic appearance, as 
well as for functional reasons, the air conditioner expansion or cooling 
coil is ordinarily encased in a molded plastic housing which supports 
blower fans directly behind the expansion coil to direct air through the 
coil and into the interior of the passenger vehicle. Such molded plastic 
cases or housings have become well known in the art and are conventionally 
referred to as molded cases. 
The expansion coil assembly, fans, etc., are usually mounted in a molded 
case which consists essentially of two mating molded pieces joined 
together to enclose the coil and fan and form a front opening through 
which the cooled air is exhausted into the passenger compartment either by 
means of ducts, bezels or the like. Moisture contained in the air forced 
over the cooling coil is often condensed on the expansion coil. This 
condensate then drips from the coils and collects on the floor of the 
case. A drain hole is provided at the lowest point on the case to allow 
the condensate to drain from the case. Since the front of the case 
projects into the passenger compartment and is usually visible, the drain 
is usually positioned near the rear of the case so that the drain will be 
hidden from view. Furthermore, it is more convenient to connect a drain 
hose to the drain hole if the drain is positioned toward the rear of the 
case. Therefore, while the air is forced through the coils from back to 
front, the flow of condensate is generally in the opposite direction, 
i.e., front to back or at least laterally when the drain is on the side. 
In many cases, however, the air flowing through the case is forced between 
the expansion coil assembly and the floor of the case and tends to move 
the water collected on the floor of the case along with the air. Water 
thus becomes entrained in the air moving through the case and is sprayed 
into the passenger compartment along with the cooled air. 
In accordance with the present invention the air conditioner case or 
housing includes a shield or false floor between the floor of the case and 
the expansion coil assembly. The shield thus provides a divider between 
the air flowing from back to front and the water flowing generally from 
front to back. The water draining from the coils may drain over the edge 
of the shield or through holes in the shield and collect on the bottom of 
the case. Air flowing on the top of the shield forces water collected 
thereon to the edge of the shield where it may then drain under the shield 
without being forced out of the case along with the cooled air. 
Furthermore, air may also be forced under the front of the shield and aid 
in forcing the water to travel from front to back toward the drain. In 
this manner the shield effectively divides the case in two compartments 
and permits the condensed water to flow from front to rear without being 
adversely affected by the flow of air.

For convenience the invention will be described herein with specific 
reference to molded plastic cases for add on or after market air 
conditioners. It will be readily understood and appreciated by those 
skilled in the art that the invention is not so limited. Similar shields 
may be used in connection with other housings for air conditioner cooling 
coils, whether molded plastic or not. It may likewise be used in 
connection with larger stationary units and the like. 
A molded plastic case employing the preferred embodiment of the invention 
is illustrated in FIG. 1. The molded case comprises an upper half 10 and a 
lower half 11 which mate to form a unitary enclosure having a top wall, a 
bottom wall and side walls. The mating halves are held together by 
conventional means such as hooks 25 extending from the lower half 11 to 
mate with notches 24 in the upper half 10. Other conventional means such 
as bolts and the like (not shown) may also be used to retain the halves in 
the desired relationship with each other. The enclosure formed not only 
defines space for enclosing the expansion coil assembly but also includes 
housings 13 and 14 for enclosing blower fans which direct air through the 
expansion coil. The case also defines a front opening 15 through which the 
cooled air exits. In normal use a bezel will be attached to the front 
opening 15 to direct air as desired. Alternatively, the front opening 15 
may be connected with an air distribution system incorporated within the 
dashboard, instrument panel or other portion of the vehicle. 
As viewed in FIG. 3 it will be observed that although the front and back of 
the case are essentially open to allow air to be directed through the 
coils, the lower portion of the enclosure has substantially vertically 
extending front and rear walls. The air conditioner cooling coil assembly 
is generally comprised of a convoluted conduit surrounded by parallel fins 
of rectangular dimensions (not shown) which fit within the cavity of the 
case. The cooling coil assembly ordinarily rests on the floor of the lower 
half 11 of the case or on shoulders or stand-offs incorporated in the case 
body. Thus air forced through the coils by the blower fans may travel from 
back to front through the entire case and carry water condensate which 
collects on the floor of the case toward the front of the case. 
Frequently, such water collects in sufficient volumes to permit the water 
to become entrained in the flow of air and sprayed through the opening 15 
into the passenger compartment. 
In accordance with the present invention a shield 26 or false flooring is 
provided. The top plan dimensions of the shield 26 are essentially the 
same as the top plan dimensions of floor 27 of the case. It is desirable 
that the rear edge 26a of shield 26 fit as closely as possible against the 
rear wall of the case so that air may not be forced between the shield 26 
and the rear wall of the case. Conversely, it is preferred that the front 
edge 26b does not mate with the front wall of the case. To aid in 
positioning the shield in the proper position and retain the shield in the 
proper position it is preferred that the lower half 11 of the case include 
stand-off dogs 28 integrally formed therein which mate with notches 29 in 
the front edge of the shield. 
As illustrated in FIG. 3 the top surface of the shield 26 is essentially 
flat. As illustrated in FIG. 4 the bottom surface of the shield is 
provided with a plurality of legs or feet 30 of equal length to support 
the shield 26 slightly above the floor 27 of the case. In this manner a 
small cavity 31 is formed between the shield 26 and the floor 27 as 
illustrated in FIG. 2. 
The shield may be provided with a plurality of holes 36 to permit 
condensate to drain from the expansion coil through the shield. The 
surface of shield 26 is preferrably flat so that the expansion coil may 
rest directly thereon. To aid in retaining the expansion coil assembly in 
the proper location within the cavity of the case, the shield 26 is 
preferrably provided with a plurality of upstanding tabs 32 along the 
front edge thereof. The expansion coil assembly may thus be positioned on 
the flat surface of the shield and pushed forward to the upstanding tabs 
32 to secure the coil assembly within the cavity of the case. As 
illustrated in FIG. 4 the upstanding tabs 32 extend slightly forward from 
the front edge 26b of the shield thereby providing a space 33 or gap 
between the front edge 26b of the shield and the front wall of the lower 
half 11 of the case. 
As illustrated in FIGS. 1 and 2 the floor 27 of the case has a sump 34 
which communicates with a drain line 35. Accordingly, water collecting on 
the floor 27 of the case drains into sump 34 and passes through drain line 
35. A case may be provided with one or more of such sumps and drain lines. 
Ordinarily, one sump and drain line is formed at the rear of each side of 
the floor of the case. 
It will be observed that when a cooling coil assembly is positioned within 
the case and resting on the top surface of shield 26 water which condenses 
on the cooling coil and fins may drain from the coil to the top of shield 
26. Any water so collected may drain through the holes 36 into the cavity 
31. Because of the flow of air flowing over the top of the shield 26, the 
water may be forced toward the front edge 26b. However, because of the 
space 33 between the front edge 26b of the shield and the forward wall of 
the case, the water forced forward by the flow of air will drain through 
space 33 into the cavity 31. Therefore the water does not become entrained 
in the flow of air but is allowed to drain from the case in the desired 
manner. Since the rear edge 26a of the shield rests against the rear wall 
of the case, air cannot enter cavity 31 from the rear. Conversely, air may 
enter the cavity 31 through space 33. However, if air flows in this 
direction the flow of air is the same as the desired direction of flow of 
water and the air may simply force the water toward the drain instead of 
out the bezel. 
Various sizes and designs of case styles are presently available. Likewise, 
depending upon the requirements of the equipment to be installed and the 
design of the manufacturer, various sizes and configurations of cooling 
coil assemblies are also available. Cases are usually designed to 
accommodate a specific coil assembly. Frequently a cooling coil assembly 
having dimensions different from those for which the case is designed may 
be used. It is, of course, desirable that the cooling coil assembly be 
firmly positioned and held within the case. 
In accordance with the present invention the shield may include adjustable 
tabs for mating cooling coil assemblies of various designs and sizes with 
a single size of housing. As pointed out above, the shield 26 preferrably 
includes upstanding tabs 32 at the front edge 26b thereof to limit the 
forward position of the front edge of the cooling coil assembly. The 
shield 26 may also be provided with a plurality of vertical holes 40 near 
the rear edge 26a. The holes 40 are adapted to mate with and retain tabs 
41 as shown in FIGS. 3 and 5. Tabs 41 preferrably comprise a rectangular 
body having opposed major faces and a post extending from one major face 
of the body in a direction normal to the plane of the major face. The post 
42 mates with the hole 40. The tab 41 is preferrably rectangular in top 
plan dimension as shown in FIG. 3 and the post 42 preferrably extends from 
the bottom side thereof near one end of the tab. Accordingly, the tab may 
be used in either of three positions. In the first position the long side 
of the tab 41 is parallel with the rear edge 26a of the shield and thus 
defines a first rear limit for the cooling coil assembly. Alternatively, 
the tabs may be rotated 90.degree. so that the short side of the tab 
nearest the post 42 is parallel with the rear edge 26a of the shield. The 
opposite end of the tab thereby provides a second rear limit for the 
cooling coil assembly. Alternatively, the tabs may be rotated 180.degree. 
so that the end of the tab opposite the post is parallel with the rear 
edge 26a. In this position the end nearest the post defines a third rear 
limit for the coil assembly. Accordingly, the tabs may be inserted as 
desired to aid in adapting the shield to retain various widths of cooling 
coil assemblies within the housing. 
Similar holes 43 may be aligned near the front edge 26b. Tabs 41 may be 
positioned in holes 43 in either of the three positions as hereinabove 
described to provide alternate front limits for the edge of the cooling 
coil assembly as desired. Accordingly, through the use of upstanding tabs 
32 and adjustable tabs 41, the front and rear limits for the cooling coil 
assembly may be adjusted as desired to adapt various widths of cooling 
coil assemblies to the cavity of the case. The tabs are preferrably molded 
plastic parts which mate with the holes 40 and 43. No special tools are 
required to adjust the retaining tabs to fit any desired cooling coil 
assembly. 
From the foregoing it will be observed that by means of the shield or false 
flooring of the invention an air conditioner housing or case may be 
divided into two compartments so that water may drain from the expansion 
coil assembly into a lower compartment which is not affected by air 
flowing through the case. Accordingly, the condensate may effectively 
drain from the coils into the lower cavity and be drained from the case. 
Air flowing through the case may force water on the floor of the shield 
toward the front edge but the water is allowed to drain from the front of 
the shield to the lower cavity without being forced out of the case along 
with the cooled air. Furthermore, the shield of the invention provides 
adjustable means for retaining the cooling coil within the case in the 
desired position to aid in stabilizing the cooling coil assembly and 
adapting various sizes of cooling coil assemblies to the size of the 
housing. 
While the invention has been described with particular reference to molded 
plastic cases, it will be readily understood by those skilled in the art 
that the principles thereof apply equally to housings of other design, 
shape and materials. Furthermore, the invention is not limited to mobile 
or vehicular air conditioner equipment but may be used in connection with 
other types of air conditioning equipment wherein the air conditioner 
expansion coil is enclosed within a case through which air is directed. It 
will therefore be understood that although the invention has been 
described with particular reference to a specific embodiment thereof, the 
form of the invention as shown and described in detail is to be taken as 
the preferred embodiment of same, and that various changes and 
modifications may be resorted to without departing from the spirit and 
scope of the invention as defined by the appended claims.