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20 isolation rooms . Isolation rooms would see a similar ACH with added filtration . Fresh air from outside replacing indoor air is the best way to manage the obvious challenge of possibly concentrated contaminated air ,” says Bester .
For general wards and common areas in these facilities , trends show a move towards natural ventilation , ceiling fans and open windows in many cases in both the public and private sectors .
“ Reception areas are often a place where HVAC gets neglected , but is one of the places that can hold the most risk with as-yet undiagnosed patients coming in and being admitted . These areas are often ventilated to minimum standard or not ventilated at all . Crowding in these areas creates significant risk of cross-contamination . HVAC design should always consider the effect that a person carrying a highly contagious disease would have on others just by sharing the same space ,” adds Schilder .
When it comes to the HVAC control systems , you also don ' t want just anyone to be able to set their own temperatures willy-nilly . More often than not , the doctors and nurses require set parameters , but when there is an open door to change set points and fiddle with panels or dials , it is natural for people to want to this , so , limiting any changes to the system should be implemented because consistency is more important .
RACA Journal I May 2021
You will also find pre-set room modes are common today that will accommodate the specialists working with cements at lower temperatures all the way through to different surgery types and paediatric care at higher temperatures .
“ Chilled water systems and steam have always been very popular in medical facilities . Instead of the packaged units that are growing in popularity , chilled water systems can be coupled to various air handling units and the nice thing about chilled water cooling systems is that they are very easy to control , and you will still see these installations at many older hospitals and are still preferred in some installations today ,” says Schaefer .
The packaged unit concept has become so popular because these systems can easily be deployed to any location including rural clinics , field hospitals , mobile units , or any remote areas . Packaged units essentially also combine all of the best knowledge and technologies available . Add to this the benefit of replacement of packaged units compared to aged / old chilled water systems mainly pipework .
POSITIVE OR NEGATIVE PRESSURES Space pressures have for some time been a topic of great discussion , particularly for medical facilities that must decide which areas should be positive and which should be negative , and how to combine designs to ensure risk areas remain controlled .
Pressures in these spaces simply refer to the principle of either keeping contamination controlled within a space or keeping contamination out of a space .
“ The latest standards for example require the passageways in a hospital ward to be positively pressurised and airflow to cascade out of the area . This is primarily to keep healthcare workers in a continual safe pressurised fresh air environment . This air may also not be pushed out to where any patients are situated ,” notes Schaefer .
The considerations are always around the position to protect the patient or protecting the surrounding environment . Naturally dealing with a very highly transmissible diseases , such as Ebola , you would need to keep the patient in a negative pressure space with double doors and an air lock to maintain an isolated environment .
“ Patients recovering from procedures like a bone marrow- or skin transplant are incredibly susceptible to infection . These patients need to be accommodated in a very high quality , clean air environment with positive pressure to make sure that no contamination can get into the room ,” adds Schilder .
In some facilities today you will also find clinical areas that have been fitted with the functionality to switch over between positive and negative pressures . There is however concerns in this around the required cleanliness and making sure that your infection protocols are being followed and maintained .
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