aircurtains

Conditionaire International

Air Curtains

Did you know? Air Curtains Increase Energy Efficiency!

Air Curtains in certain applications cut down on running cost to air conditioning / refrigeration equipment as much as to pay off the price of the air curtains within 4 months of operation then it’s just money back in your pocket!

AIR CURTAIN PERFORMANCE & SAVINGS
The following pages contain reports that have taken place in various locations and with various conditions. These reports are to purely give some indication on the energy and costs saved when utilising air curtains.

This first report was commisioned around the early 1970's.

CONDITIONAIRE JET AIR CURTAINS

TECHNICAL DATA

HEAT LOSSES THROUGH DOORWAY

WITH AIR CURTAINS BALANCED

Convection Air Flow Zero

Heat loss through curtain 13 BTU/sq,ft,/1° F/Hr.

(obtained from actual field tests)

Area of door 6’ x 3’ = 18 sq.ft.

Temperature difference = 47° F

Heat Loss = 18 x 1.3 x 47 BTU/minute

60

= 183 BTU/minute

Ratio of heat losses –

Total heat loss through doorway

Without air curtains = 1691.9 BTU/minute

Heat loss through curtain = 183 BTU/minute

Ratio = 9.2

HEAT LOSSES THROUGH INSULATED DOOR

Assuming door insulated with 3" corkboard with "K" factor of

.28 BTU/sq.ft./inch thickness/1° temperature difference/hour

Outside Conditions:

85° F D.B. 50% R.H.

Inside Conditions:

38° F D.B. 90% R.H.

Temperature difference: 47° F

Area of door 6’ x 3’ = 18 sq.ft.

Heat loss through door = .28 x 47 x 18 = 77.8 BTU/hr.

= 1.3 BTU/min/doorway

SUMMARY OF HEAT LOSSES

1. Through insulated door 1.3 BTU/min (77.28/hr)

2. Through air curtain 183 BTU/min (10980/hr)

3. Through open doorway (no protection) 1690 BTU/min (101460/hr)

PROJECTED SAVINGS

Conditions: 1) 6' x 3' doorway = 18 sq/ft

2) outside 85° F 50% R.H.

3) inside 38° F 90% R.H.

4) AT = 47° F

Through Air Curtain 183 BTU/min (10980/hr)

Through open doorway 1.690 BTU/min (101460/hr)

Difference = 1507 BTU/min (90480/hr)

3412 BTU’s = 1kw/hr energy

\ through air curtain v/s doorway

= .44kw/h per min or 26.53 kw/hr

Say doorway was open for 40 hrs/wk = 1060.73kw/hrs

3 months is 13 weeks = 13789.45kw/hrs

Depends on Cop of unit+ take into effect of subtracting air curtain energy costs

Electricity costing as per our bill 10.1c /kw/hr

3 mths 13789.45 kw/hr

x 10.1c per kw/hr

= $1,392.73

*This report was commisioned in 1997

REPORT ON AIRCONDITIONING LOSS

THROUGH DRIVE-THRU WINDOWS

Following our site visits to the Casula store, we tested the air loss through the open window of the servicing area, the tests showed the following results.

The open window dimensions are 650mm wide and 1300mm high. The average loss of air conditioned air through the open window was measured at 0.8 metres per second.

The temperature difference was only 4° C from inside to outside.
There is more loss when difference in temperature is greater.

The loss of conditioned air with the above conditions is 676 litres per second. (Refer to diagram A).

The above test was then carried out with the Conditionaire Air Curtain running and the loss of conditioned air was nil. (Refer to diagram B).

The Conditionaire Air Curtain successfully stopped the convection currents set-up by the open window, which as shown will save the owner energy costs from continual running of the air-conditioning system.

For example: One (1) only window as above,

4kw to condition 676 litres of air per second =$0.48 per hour

0.1kw to run air curtain =$0.01 per hour

Saving Total =$0.47 per hour

Therefore: One (1) only window open 1 hour per day over a one year period the saving is a total of $171.65

One (1) only window open 8 hours per day over a one year period the saving is a total of $1,372.40

Note: These figures were supplied by Energy Australia, and do not include for
Maintenance costs involved to run the air-conditioning system for longer periods, due to loss through open window.

Added Benefit of the Air Curtain

Along with the cost saving benefit, the air curtain will also deter flies and insects.

This is achieved by containing the odours that attract the flies and insects.

The principle applied is that flies and insect dislike the atmosphere around them to be disturbed so as deterring them from entering.

With the air curtain running whilst window is closed, flies and insects would not sit on sill awaiting entry, as was the previous case.

Air curtains have long been used by the meat industry and are specified and recommended by the Department of Primary Industry for fly and insect control in abattoirs.