Comparison with traditional cooling and heating systems
Open plan office
Main duct and outlets
Perimeter outlets
Comparison with traditional heating systems
Central heating
Central heating delivers heated water around a loop of insulated copper pipework connected to delivery points, i.e. the radiators. Each radiator is made up of fins of metal that heat up when hot water is passed through them. They heat the room using convection. Convection is the reason why fire travels much faster upwards than to the sides.
Radiators only heat the space directly around them. This space has a higher temperature than areas further away, particularly at low level. They are unable to draw the cooler air from around the room towards them, except for the convection effect. Anyone sitting near a radiator will get too hot. The time taken to heat the whole room can be considerable as there is no air movement in the middle of the room. Air movement is only caused by people moving around or by a separate ventilation system.
Whereas a wall mounted radiator provides a single point of distribution for heating or the cooling, the Hi-Velocity mini duct system has multiple points of distribution. This provides even temperatures throughout the whole area, with no draughts. You will feel comfortable at all times.
Under floor heating
The Hi-Velocity system has three key advantages over under floor heating:
- Air conditioning, ventilation and air purification can be added as inexpensive extras. Under floor heating has no cooling option
- Response time is rapid. Even temperatures are achieved quickly, whether you need to warm up or cool down
- Each room can have its own time and temperature control. This increases energy efficiency and ensures everyone enjoys their choice of temperature
Under floor heating is rarely an option for commercial applications. It does have the advantage of having no radiators, thus freeing up wall space. Systems are electric or water. Electric systems are cheap to buy but can be expensive to run. Water systems use pipework under the floor, which is set into a concrete screed. Although popular for residential applications, it means a completely separate cooling system will be required if air conditioning is to be installed.
Comparison with traditional cooling systems
Wall mounted systems
Traditional air conditioning solutions are single ducted or wall mounted split systems. One system would be positionrd centrally within the space or a pair of units could be used, each delivering half the required duty.
These traditional cooling systems work by having an intake point and an exhaust point. A built in fan motor creates the air movement. Air within the space is drawn towards the fan coil and taken in. It is then pulled across a refrigerant coil and blown out at a reduced temperature. This can create draughts and be uncomfortable for the person sitting in the path of the cold air. It can be difficult to eliminate the probelm of hot and cold spots.
The Hi-Velocity system has many advantages over wall mounted systems:
Creates even temperatures with no hot or cold spots - outlets are positioned in ‘out of traffic’ areas.A combination of Bernouli’s Theorem and the Venturi Effect ensures an even temperature distribution.
Save space The wall-mounted system will naturally draw the eye and take up wall space. Trunking is required to cover refrigerant pipe work from the unit to the ceiling. Hi-Velocity outlets are discreet and do not interrupt the flow of either the walls or ceilings.
Improves energy efficiency A single Hi-Velocity system will use one 14kW Daikin Inverter condensing unit, in place of two condensing units with the wall mounted option. The Hi-Velocity is fitted with an inverter fan motor. A pressure transducer can be included, which will allow the fan to slow down if one or more of the control zones are shut down. In this way, the fan motor and condensing unit run only at the speed required.
Having several control zones allows a diversity factor where the cooling load will be moved to the areas where it is required. In other words, during the day some areas may require cooling but others, such as bedrooms, are unlikely to be in full use. This may be reversed in the evenings.
The hot water service allows the system to heat the whole area with all zones open. Based on water on at 60○C, the HE101 will distribute 19kW of heating. The controllers can set to bring on the hot water (as well as the heat pump condensing unit) whenever the set point is more than 2○ C above the room temperature.
When the room is up to temperature the system will cycle on and of using only the heat pump.The “constant fan” mode allows the fan to run in a slow speed when the system is neither heating nor cooling. This adds to efficiency by acting as a de-stratification system, which distributes the heat in a more even way and thus reduce the time that the heating system is required to operate.
Reduces noise Each wall-mounted option is likely to require a condensate pump, which will give a buzzing noise when operating in cooling mode and are subject to mechanical failure from time to time. The Hi-Velocity system will have a single condensate removal point and, being positioned in the loft area, will be able to use a gravity condense line.
Reduces carbon footprint The Hi-Velocity system reduces the number of machines required and also reduces the number of fan motors, blades, PCBs, filters, and consequently reduces time spent on manufacturing and transportation.
Improves indoor air quality If required, fresh air can be introduced to the return airside, mixed with the conditioned air and distributed through the system. The High Efficiency Purification System (HEPS purifier) is a three in one air-cleaning unit, which can be added to the Hi-Velocity system.
Comfortable, air-conditioned corridors The Hi Velocity system can allow for conditioned air to be fed in to the corridors to give an even distribution through the apartment. This option would not be sensible with the wall-mounted option.
Comparison with conventional forced air systems
The Hi-Velocity system has three key advantages overconventional forced air systems:
- The Venturi Effect eliminates hot and cold spots, which are normally associated with conventional forced air systems
- Designing duct layouts is substantailly easier because vent outlets no longer need to be located on outside walls
- Ducting is sound attenuated to resolve problems with noise