R A Y H U D S O N MAYFAIR W1K. 21 st March 2011

Transcription

1 R A Y H U D S O N VENTILATION EXISITNG AND PLAN MAYFAIR W1K 1 21 st March 2011

2 I N I T I A L I Z AT I O N A N D S U M M A RY VENTILATION AND LOCALIZED HIGH SPORE CONCENTRAION MAYFAIR W1K Report from the resident that a deterioration of health occurs during occupation of Mayfair W1K led to a micro bacterial analysis showing unacceptably high readings in particular area s that gave rise to the resident being moved out and a causal systems to be investigated. The identified moulds Stachybotrus & Chaetomium, + Penacillium/Aspirgillus are all common forms of mould and when found in the home are often noted to be associated with a structural damp typically wooden or plaster material whose humidity content maintains a high surface water vapour pressure. In recent times it is known that water ingress to the dining room from the bathroom has occurred and caused a damp area to the wood panelling in the dining room. The extract mechanical ventilation system that serves the WC and bathroom area s runs continuously, from inspection considerable amounts of dust and debris is loose within the ducting and some signs of condensate seen on the lowest levels, additionally the motor in the attic forms the lower part of a u section with the resultant build up of debris. The high extract rate of the ventilation unit provides a significant negative pressure differential to external air. SUMMARY The current extract ventilation system sucks air and contaminates including moisture and spores through and into the house living area, this is consequential of the sealed nature of the windows and doors, this intake air percolates through inlets and cracks. The existing over powerful fan requires replacement, the very high level of dust and debris in the system along with the condensate conditions at low level provide a breeding ground for mould spores that have a conduit to distribute through the duct to other areas. Samples of air and surface humidity levels around and behind the dining room panelling are to be determined to be sure this area is not acting as a breeding source. As required the removal drying/ replacement of any high vapour component is essential. The void service area behind the bath and cupboard in the basement requires inspection as this is a possible water source. A positive balancing ventilation system with G3/F6 supply air filtration is recommended providing filtered air to the primary living areas: Dining Room, Lounge (x2) Bedroom (x3), Prior to operation an extensive cleaning program will be required as recommendations in section 10.

3 Contents Item Page Front Page 1 Initialization and Summary 2 Contents 3 Ventilation Inspection 4 Ventilation Photo s 5 Sub surface Inspection notes 6 Sub surface Photo s 7 Cleaning requirements 8 Recommendation 9 References 10 3

4 VENTILATION INSPECTION System The current system employs a twin Roof units extractor with a stand by fan system, this is located in the attic with the fan running continuously, the exhaust venting through the roof. The circular inlet ducting reduces from 25cm down to 10cm on one side and extracts from the on-suite attic bathroom and continues down a level to extract from the master bathroom. The other intake to the fan extends through 25cm circular ducting through the attic rising around 1m then going through to the house roof fire escape area before going down through 90 0 vertically to each level serving the WC on the mezzanine floor, Bathroom on the ground floor and WC in the basement area. Inspection The baroscopic inspection of the inlet ducts have shown excessive detritus building up and going through from the 100mm round duct to the vertical stack. At low level condensate signs are seen within the cumulative debris providing near perfect conditions for spore breeding and distribution through the duct system. The examination of the system is recorded and now available on CD. Some still extracts from this recording are placed on the following page Extract The QPTX extracts at around 1400m 3 /h taking in to account the duct pressure resistance, this offers 233m 3 /h for each of the WC or bathrooms, the require level for each bathroom = 54m 3 /h and for each WC = 21.6 m 3 /h. The Total minimum extract for this property should be 228m 3 /h design ideally 300m 3 /h The 1400m 3 /h is over rated by at least a factor of 4 Conclusion The over powerful ventilator running at 350 watts continuously is unnecessary and causing significant negative pressure within this property with the resultant extraction of make up air and spores from the void area s. This unit requires replacement along with a thorough cleaning and renewal of the corroded duct section in the basement. The addition of a balanced filtered intake ventilator system will insure against further high spore counts. 4

5 VENTILATION PHOTO S Attic fan internal connection System twin fan Intake Port Inner of intake port Duct condensate WC Basement Debris Duct Ground WC Duct corrosion WC Basement Debris in Duct 5

6 SUB SURFACE INSPECTION NOTES All area s were viewed via baroscopic examination, still pictures taken from movie are shown on page 7 with CD available showing full movie Main On Suite bathroom Inspection area s; below shower tray, back of the bath, behind WC and through inspection port in to vertical service duct. These area s were seen to be dry with no signs of mould propagation. Dining Room Inspection area s; through inspection port in to vertical service duct. These area s were seen to be dry with no signs of mould propagation. Lounge Inspection area s; through inspection port in to vertical service duct. These area s were seen to be dry with no signs of mould propagation. 6

7 SUB SURFACE PHOTO S Sub-Shower on-suite Master Bed Bath on-suite Master Behind WC on-suite Master Dining Room Service Duct Lounge Room Service Duct 7

8 CLEANING REQUIREMENTS Moulds can be found almost anywhere; they can grow on virtually any organic substance, as long as moisture and oxygen are present. There are moulds that can grow on wood, paper, carpet, foods, and insulation. When excessive moisture accumulates in buildings or on building materials, mould growth will often occur, particularly if the moisture problem remains undiscovered or unaddressed. It is impossible to eliminate all mould and mould spores in the indoor environment. However, mould growth can be controlled indoors by controlling moisture indoors. Guidelines Method 1: Wet vacuum (in the case of porous materials, some mould spores/fragments will remain in the material but will not grow if the material is completely dried). Steam cleaning may be an alternative for carpets and some upholstered furniture. Method 2: Damp-wipe surfaces with plain water or with water and detergent solution (except wood use wood floor cleaner); scrub as needed. Method 3: High-efficiency particulate air (HEPA) vacuum after the material has been thoroughly dried. Dispose of the contents of the HEPA vacuum in well-sealed plastic bags. Method 4: Discard - remove water-damaged materials and seal in plastic bags while inside of containment, if present. Dispose of as normal waste. HEPA vacuum area after it is dried. Guide to Schedule of works Ventilation system 1. Removal of fan 2. Replacement of 100mm duct leg in the basement WC 3. Clean ducting within existing system as required to HVCA TR19 4. Renew existing extract fan with energy efficient unit at the appropriate extract rate 5. Renew all extract terminals 6. Install new intake air system with air filtration supplying main living area s Household 1. Vacuum and wipe clean all surfaces 2. Porous material surfaces to be steamed cleaned 3. Ensure all surfaces are left dry 4. Use anti-fungicidal solution and dilute bleach only if required and directed 8

9 RECOMMENDATION General Notes Mould spores are always present, the proliferation within the indoor environment requires water the same as any plant (same life cycle), most building materials have a water content and will not provide the amount of water required to enable mould spore production. However once a material has become wet or exposed to excess moisture then the surface vapour pressure supports mould reproduction with the ability then for the mould to be able to self perpetuate from the humidity in the air, the mould also become embedded in absorbent materials and ready to grow as soon as the right conditions occur. Eradicating the mould requires cleaning and drying the surface and ensuring that the moisture laden conditions do not return. The current ventilation system is sucking mould spores in to the living space, this can be coming from any of the void sections and service routes in to this property and likely to be a subterranean source where these moulds naturally propagate. As a precaution a further Inspection is required behind the panel on the internal wall of Dining room as well as the basemen service duct. Dining Room Panel Surface and subsurface moisture level detection, compare results with known dry surface of same material, If excess moisture found, remove panel dry surface and renew the wood panel Basement Service Area The basement contains a void section carrying the heating pipes to the boiler, this area requires investigation to ensure it is dry. Ventilation (existing) Attic 1. Replace existing fan system with more efficient unit of correct extract rate 2. Clean internal ducting system 3. Renew inlet valves 4. Clean internal duct work 5. Replace as required 100mm duct to basement WC 6. Baroscopic inspection following cleaning work Ventilation New Provide intake filtered air that balances the extract air, this air flow is to be provided in the main living area s and in particular the inner dormant area s of the lounge and dining room Attic Installation 1. Intake port 2. Intake fan 3. Inner attic (emergency escape route) 4. Air Filtration system filter exchange position Supply Air Installation 1. Master Bedroom 1 2. Bedroom 2 (top floor) 3. Bedroom 3 (top floor) 4. Office/Attic lounge 5. Lounge 96. Dining room

10 REFERENCES World Health Organisation WHO GUIDELINES FOR INDOOR AIR QUALITY: DAMPNESS AND MOULD 2009 ISBN On the history of indoor air quality and health HSE Heating, ventilation and air conditioning HSE Control guidance sheet 200 Local exhaust ventilation HM Government Approved Part F The Building regulation 2000 F1 Means of Ventilation October The 'Associated Code Of Practice from the Health and Safety Commission' requires that all mechanical ventilation systems should be cleaned, tested and maintained to ensure no contamination of air distribution and potential fire risks, whilst ensuring the lifespan of the system Duct Cleaning HVCA TR Ray Hudson ray@rhldirect.com