below are some of the installation factors to be considered
Suction Unit - Plant Room Essentials for your Installer
The suction pipe work system utilises DWV PVC pipe and connects each dental surgery back to the suction unit in the plant room. The suction unit should be installed on the same floor level or below the level of the dental chairs. It should have constant fall towards the from the chairs to the suction unit and cannot include 90° junctions, dips, “U” shapes or rises. Termination within the dental surgery is typically at the floor junction box of the dental chair, but is site dependent. The chair manufacturer or installer should be consulted for location
o Suction Inlet connection:
Termination of suction pipe work system that connects to dental surgeries
o Waste connection:
Sewer drain pipe terminated lower than waste outlet of suction unit
o Exhaust air outlet connection:
Pipe work which directs exhaust air to atmosphere outside the building
o Power supply:
Dedicated electrical power circuit to run the suction unit
o Control switch wiring:
Switch wiring to connect the dental surgeries to the suction unit
Plant Room Essentials for your Installer
The compressed air pipe work system is typically copper and connects each dental surgery
back to the compressor unit in the plant room. Termination within the dental surgery is typically at the floor junction box of the dental chair, but is site dependent. The chair manufacturer or installer should be consulted for location details.
o Compressed Air Outlet connection:
Termination of compressed air pipe work system that connects to the dental surgeries
o Power supply:
Dedicated electrical power circuit to run the suction unit
o Waste connection (optional)
Sewer connection to allow drainage of compressor condensate
Location and Access
Where to position your Plant Room
When building a new practice the location of your plant room should be given consideration. Thorough planning will ensure efficient and balanced suction performance. The plant room should be close to the surgeries to prevent losses incurred from excessive pipeline lengths. Centralising the plant room location will reduce the distance of pipelines and ensure better performance. The plant room must be positioned on the same floor level as the dental chairs or below this level. If there is a floor level below the dental chairs (i.e. a car park or basement) that is accessible and in close vicinity to the dental suites above, this position would be beneficial as fluids would fall to the pump.
MAXIMISE YOUR SYSTEM’S PERFORMANCE
Air is required to flow through a suction pipe work system to assist the aspirated fluids evacuation to the suction unit. For many reasons associated with different site scenarios, it is possible for an insufficient volume of air to flow through the system. This can lead to fluctuations in performance as fluids accumulate, restricting air flow below optimal levels. Air Injector Valves can be installed to the extremities of the pipe work to compensate the lack of air volume.
There are two types available:
o Air Injector Valve - This is a constantly variable unit that allows small volumes of air over long periods. It is a simple spring loaded, vacuum actuated valve. It is designed to open at the same time as the chairs are in operation.
o Automatic Air Injector Valve - This is an automated unit that allows large volumes of air over short periods. It is an electro-pneumatic valve that is actuated by an electrical signal. It is designed to open only once all chairs have ceased operation. With no air flow being required from the chairs, the valve is able to allow a large volume of air to be injected into the system without compromising performance to the dental chair.
In all new clinic constructions, Cattani highly recommend to make provisions for an Air Injector Valve to be fitted. It is far simpler to install an effective Air Injector Valve to existing services rather than to add them later. It is recommended to extend the suction pipe line past the furthest chair from the suction unit and have it terminated in an accessible area (like a cabinet, ceiling space, void etc), that is higher than the main suction pipe line. An additional switch cable between this point and the suction unit in the plant room is also required. Ensure the pipe is capped if an Air Injector Valve is not being installed at that stage. Retro fitting an Air Injector Valve into a system that does not have the extra pipe work can be achieved by fitted it into the floor junction box of the dental chair. However the noise generated by the aspirated air can be difficult to manage.
Pipeline Design and Layout
The pipeline should work to facilitate the flow or air and fluids back to the plant room. Pipelines should be designed with a main pipe to which branches from each dental chair connect. Large clinics may also require sub-branches. Where possible it should take the shortest and straightest route between the plant room and the last dental chair on the line. The size of the pipe reduces the further away from the plant room, according to how many dental chairs that section of pipe is connected to.
Pipe size is very important to control even air flow and efficient evacuation of fluids. The following list outlines suction plumbing requirements based on an the average air flow rate of 350 L/Min per chair.
1 - 2 Chairs - 40mm DWV Pipe
3 - 6 Chairs - 50mm DWV Pipe
7 - 10 Chairs - 65mm DWV Pipe
Bends in the pipeline should never be greater than 45°. 90° bends can be achieved by using 2x 45° bends together in-line. All branches entering a main line will utilise 45° junctions. Do not use a T-Junction when splitting main lines split into two branches. A configuration utilising a 45° Y-junction for the first branch off the main line and then 2x 45° bends to achieve the second branch is to be used.
RISE & FALL
The pipeline should achieve a constant fall back towards the suction unit in the plant room. Dips, U-shapes to go around beams etc. should be strictly avoided as fluids will pool at the low point and restrict air flow. If the suction unit is installed on the same floor level as the dental chairs a single vertical rise should be installed just prior to the unit and be kept to a minimum height. The higher this rise, the greater the risk of fluids creating a wave affect as they try and reach the inlet of the suction unit. This may cause fluctuating performance at the suction tips.
HOW DO YOU CONTROL THE TEMPERATURE IN YOUR PLANT ROOM?
Air Conditioning is the most efficient option to control temperature in your plant room. Modern split systems are an affordable option. They are quiet and also efficient to run. Installing an air conditioner in your plant room means that no vents are required so noise levels emitted are greatly reduced. The temperature can be kept at a stable level which is optimal for the equipment to operate. Always install a dedicated air conditioner to your plant room. Do not utilise the central system that is installed in your clinic by ducting a branch into your plant room. The central system is designed for human comfort and the thermostat is usually located in reception. It does not sense the temperature in the plant room where equipment is generating heat. Central systems are not always set to cool. In winter your central system would actually be adding heat to the plant room.
Recommendations for plant room air-conditioning:
1 - 4 surgeries 2.5 kW
6 - 8 surgeries 4.5 kW
4 - 6 surgeries 3.5 kW
8 - 10 surgeries 5.5 kW
FAN FORCED VENTILATION
Fan forced ventilation systems produce a turnover of air in the plant space. Cool air is drawn into the space whilst hot air is exhausted out via the inline fan. It is recommended to install a fan capacity of 100m3/hr per 1 kW power rating of you equipment.
Considerations for this method:
o Noise: Vents for air to flow through the plant room allow noise from the equipment to escape.
Cooling fans generate additional noise.
o Temperature: An efficient fan forced ventilation system will only reduce the temperature to 10° C above the incoming air temperature. Temperature control is only as consistent as the incoming air temperature.
All plant room equipment generates noise. This noise may be distracting to dentists, patients and staff. It may also not comply with council and body corporate regulations. Noise can be difficult to manage as often the steps taken to avoid noise escaping the plant room will cause equipment to overheat. Often a balance between ventilation and noise control needs to be reached.
o The plant space can be air conditioned to eliminate the requirement for vents
o The plant space may be lined with sound-deadening material
o Acoustic Covers are available for a select model range
o Mufflers can be fitted to the suction exhaust outlet
o Fan forced ventilation vents can be baffled to allow air-flow and reduce noise
A simple baffle can be employed to reduce noise escaping from vents. Essentially, there is a box placed over the vent with one open end. Air can pass through but noise is absorbed. The box can be constructed of similar materials to that of cabinet doors and for optimal performance should be lined with sound-deadening material. Consideration should be given to the surface area of the open end of the box so as to not restrict the volume of air flow. Restricting the air flow will impede the efficiency of the ventilation system. C.A.P.S. (Controlled Atmosphere Protection System) is a self contained, outdoor plant room solution provided by Cattani.