In line with Ford and Doonan’s commitment to exceeding the industry standard in everything we design, install and service, here is how we do it with a new ducted reverse cycle air-conditioner.
EQUIPMENT
Ford and Doonan will only ever recommend a quality and energy efficient brand of equipment. This is just the start of creating an efficient ducted system.
DUCTWORK
Ford and Doonan use and recommend the unique and exclusive “Gold Duct”. This duct has 75mm of installation of an R rating of 1.2. This exceeds the industry norm of 50mm duct or R1.0 or in some cases 25mm 0.7.
HUNG DUCT
Ford and Doonan installation manual that all our installers adhere to insists all flexible duct in the roof by hung level and straight with Blue band. This creates a level smooth and straight path for the air to travel through. By installing this way the indoor fan works against less resistance and delivers more air to each room. More air, more capacity.
DUCT SIZE
Ford and Doonan’s design manual and specification has been created to improve performance, not save money by installing too smaller ducts.
By using larger sized ductwork through out the roof we allow the indoor unit to deliver more air and more capacity.
DUCT LEAKAGE
Ford and Doonan use only fittings that do not leak the valuable cold air into your hot roof. Some suppliers use fittings that can leak up to 5% of the supply air quantity. Add a sloppy installation method with poorly sealed joints and this leakage rate can exceed 10%.
OUTDOOR UNIT AIR RECIRCULATION
Many domestic and even commercial installations see the outdoor unit located next to fence or other obstruction. This is often unavoidable but can have a significant negative effect on the unit’s performance.
Above 35oC every 1oC rise in outdoor temperature reduces the systems capacity by 1%!
With an outdoor unit within 1m of a fence the outside temperate may be 35o but with air recirculation the unit may be drawing in 45oC air. This equates to a 10% loss in system capacity!
Ford and Doonan have designed a unique “air guider” system that can be added to the outdoor unit to direct the hot air away from the fence and reduce air recirculation by 80%.
FRESH AIR ECONOMY CYCLES
It is cooler outside than it is inside! Ford and Doonan have developed their own cost effective economy cycle that allows you to draw in the cool night or early morning air when your home or office still needs cooling. This allows you to run your air conditioner on fan only, reducing the power consumption by 93% (Ford and Doonan’s unique system offers a double benefit, by discharging the warm room via the ceiling space and in the process lowering the spaces temperature further reducing the heat load).
ROOF VENTILATION
The roof space temperature in summer can exceed 60oC. This heat is adding to the rooms heat load so it makes sense to reduce it. The addition of “Whirly Bird” type roof ventilator can reduce roof space temperature by up to 8oC.
SAVINGS CALCULATOR
Assumptions
Equipment:
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Daikin FDYQ160 capacity 15.0KW
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Power input 5.55kw
Installation: Typical Residential 10 outlet single storey. Multi-zone
Run Times
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Summer 900hours over 4 months.
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Winter 500hours over 4 months.
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Total 1400hours per year (7770 kw hours/pa) or 7.77 tonnes CO2
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Duty Cycle (average run capacity of inverter) – 75%
Ductwork
- R1.2 Duct vs R1.0 Duct
- Summer running hours only 900 @
- Roof space temperature of 50oC
Saves 303kw hours/pa
285kgCO2
R1.2 Duct vs R0.7duct
Summer running hours only 900 @
Roof space temperature of 50oC
Saves 1397kw hours/pa
1313kgCO2
HUNG DUCT
Fully Hung Duct type Ford and Doonan installation vs typical residential installation with ductwork not hung level and excess duct left in layout.
Increase in state pressure 50pa -
Saves 1050 kw hours/pa
987kg CO2
DUCT SIZE
Ford and Doonan specify a design with a branch duct velocity of 3.5m/s vs an undersized design with a velocity of 5.0m/s causing an increase in pressure drop 100%, reduction in airflow by 21%.
Saves 1260kw hours/pa.
1184kg CO2
TOTAL SAVINGS
At Power cost Rate of 15.32c/kw/hour (April 09)
Duct insulation R1.2 vs R1.0, hung duct, sized duct
Saves $400.00 pa or 2.6 Tonnes of CO2pa.
Duct insulation R1.2 vs R0.7 hung duct, sized duct
Saves $567.00pa or 3.7 Tonnes of CO2pa.
At Power cost Rate of 17.61c/kw/hour (July09)
Duct insulation R1.2 vs R1.0, hung duct, sized duct
Saves $459.00 pa or 2.6 Tonnes of CO2pa.
Duct insulation R1.2 vs R0.7 hung duct, sized duct
Saves $652.00 or 3.7 Tonnes of CO2pa.
*** 1kw = 0.94kg CO2
Additional optional savings
- Air guiders
For an outdoor unit adjacent to an obstruction. Projected loss of capacity 5% (averaged, year round)
Reduction in recirculation 80% = 4% saving in losses
Saves 310kw hours/pa or $55pa
Note: Air guides are most critical on very hot days when recirculation can lead to a complete shutdown of the outdoor unit or a reduction in capacity of over 15%. This is the equivalent of 6.0HP becoming 5.0HP when your heat load is greatest.
- Fresh Air Economy Cycles
Residential – Assuming you run on economy cycle only 60 nights per year, for 8 hours a night in lieu of 8 hours on cooling mode with a 50% duty cycle.
Saves 1140kw hours/pa or $200.00pa
Commercial – Running a commercial 15.5kw system 8.00am to 5.00pm, Monday to Friday will consume 17316kw hours/pa. Assuming a 50% duty cycle then a 20% economy cycle mode use.
Saves 1731kw hours/pa or $457.00pa (Commercial tariffs).
Click here to see a report on potential savings >