PART 2 Guam Marine & Navy Facilities Design

Transcription

1 Guam s Challenging Design & Construction Environment PART 2 Guam Marine & Navy Facilities Design Meeting Guam s Challenging Hot Humid Climate and other Guam challenging Issues by using lessons learned, ideas and concepts from others and actual construction of recent completed Navy Guam Housing projects using this information 29 July

2 NORTH TIPALAO HOUSING PH I & lpl Recent Guam Naval Housing meeting Guam s hot humid climate and other challenges that will be partially discussed in Part 1 and 2 of this presentation

3 2 - Guam s Hot Humid Climate Definition of a Hot Humid Climate: A hot humid climate is defined as a region that receives more than 20 inches of annual precipitation and where the monthly average outdoor temperature remains above 45 degrees F through out the year. From--Building Science Corporation and ASHRAE definition of a hot-humid climate. Guam climate temperature range is from low 70s to mid 80s year around, 70% to low 80% humidity and annual precipitation of approximately 90 inches 3 3 3

4 A- Design Principals for Guam Hot Humid Climate Guam's hot humid climate requires special design knowledge, material selections, mechanical design and construction methods. Not designing for and addressing Guam's hot humid climate will lead to corrosion problems, structural failure, moisture and mold problems that are costly repairs and the loss of use of the facilities while repairs and mitigation are being performed

5 Design Principals for Guam Hot Humid Climate Hot Humid Climate: A. Design B. Mechanical C. Moisture and Mold D. Construction E. Sustainability Renewables 5 5 5

6 A. Design Principals for Guam Hot Humid Climate A. Guam s Ventless Construction is due to typhoon driven rain and Guam s marine corrosive environment. Facilities are design to prevent outside moisture entering and air tight construction for energy efficiency. Guam s needs special design detailing and specifications. B. Guam s climate challenge for mechanical systems control of AC (sensible), indoor humidity (latent) & controlled ventilation. C. Guam s careful material selection durability, low maintenance, corrosion resistance, mold/moisture resistance,, termite resistance, breathability for the prevention of second vapor barriers D. Guam s construction methods 6 6 6

7 A. Design Principals for Guam Hot Humid Climate Conditioned Cathedralized Space- formerly call an attic 1 Guam uses vent less construction due to the typhoon wind driven rain and Guam s marine corrosive atmosphere. 2 Due high energy requirements and control of moisture, the perimeter building envelope are sealed and air tight including walls, roof, foundations and slab on grade with the vapor barrier on the warm side. Ventless Wall Section 3 The wall section does not represent Guam s concrete construction, however, the wall section does show the perimeter being sealed

8 A. Design Principals for Guam Hot Humid Climate 4 Spray foam insulation on the interior face of the exterior walls and under side of roof deck helps to create an air tight enclosure and meets UFC pressure testing requirements for LEED & Energy Star. No insulation on exterior side of the building due to damage from typhoon flying debris. 5 Consider not using wall insulation due to mass of the wall (minimum 6 thick concrete walls) to prevent rough use damage, hidden moisture and mold problems allowed by ASHREA 90.1 & possible cost savings. 6 Fiberglass insulation on the inside of the exterior envelope should not be used as this insulation is not an air barrier, hard to install in all areas, holds moisture and mold can develop. Also careful consideration on whether to use faced or un-faced fiberglass insulation due to 2 nd vapor barrier issue. This insulation is fine for sound control in interior walls

9 A. Design Principals for Guam Hot Humid Climate 7 Due to flooding of ground floors during typhoons, ceramic tile or concrete flooring should be used along with door seals, vestibules and floor drains with trap primers at all entrances. Carpet and VCT should not be use on ground floors. 8 Select materials that are not a food source for mold and termites. Examples of non-food source are paperless drywall, non cellulous spray on foam insulation, aluminum cabinets, non cellulous lo (wood) products, G90 light gage steel interior framing, ceramic wall and floor tile, plastic trim, solid surface window sills, plastic medicine cabinets, coated wire shelving systems and so forth

10 A & B -Guam Hot Humid Climate 9 All interior spaces that are to have positive pressure including all soffits, attic spaces, closets, bathrooms and ducts spaces 10 Prevent a second vapor barrier that traps moisture & leads to mold between the exterior first vapor barriers. All interior surfaces and materials must breathe. Examples of non-breathe able materials that create second vapor barriers are paints, coatings, wall coverings, sheet vinyl flooring, carpets and padding, mirrors, acrylic solid surface tub surrounds, stainless steel back splashes, cabinets, wall hangings, and so forth. Examples of breathe able materials are ceramic floor and wall tile, paints, mirrors, wall hangings and cabinets with air space behind, etc

11 B- Air Conditioning Dehumidification & Controlled Ventilation Mechanical Systems: Problem: 1. Since early 1990 s industry introduced the use of super moisture barriers and insulation creating tight energy efficient buildings. Prevented moisture penetration ti from the outside. (GOOD) Also, prevented movement in the other direction Prevents interior moisture from escaping and trapping humidity inside. (NOT GOOD) Indoor humidity promotes indoor corrosion, poor indoor air quality, and moisture and mold damage to interiors and to house hold goods. 2. Can not control power outages that can be weeks after a major typhoon. 3. Can not control people from wanting to open doors and windows on a nice day, then closing these openings and trapping moisture inside

12 B- AC, Dehumidification, Ventilation Systems Mechanical Systems: Solution: 1. AC Systems should be designed in conjunction with Guam s tight building envelope and vent less construction. 2. Design to control indoor humidity, and reduce risk of moisture and mold. This can be done by using energy efficient dehumidifiers that can run when even the AC is off when emergency generators and plug in ready emergency generator back-up separate electrical system are available. 3. In Guam all, most facility storage areas should be in conditioned spaces. Example Navy families do not want exterior storage including storage in garages due to their belongings being subject to mold, moisture and corrosion damage. 4. All interior spaces including soffits areas and ductwork spaces shall have positive conditioned spaces

13 B. North Tipalao & Apra Mechanical Systems Today s energy efficient central AC systems controls humidity from coming in from the outside but can not remove or remove efficiently indoor generated humidity once inside the facility. There is a real need to control indoor humidity that is a major cause for moisture, mold and corrosion in Guam. Whole house dehumidifiers located under air handler & using same floor drain can remove indoor humidity even when AC is not running. Note: Access panel in vertical duct for cleaning. Duct cleaning at turn over of facility and approved duct cleaning plan

14 B North Tipalao & Apra Housing For both North Tipalao and Apra housing, this is a typical air handling closet with the ac air handler on top and the dehumidifier underneath with both systems using the same floor drain. This closet has a fully louvered door. Indoor humidifier shown here is not expensive and can remove moisture problems a safety net

15 C - Moisture & Mold Guam s Moisture and Mold are huge challenges in the design of military facilities. Mold M spoors are all round us and can not be eliminated i Mold spoors requires both food and moisture to grow into mold Mold control is either by eliminating the food source (cellulose) or eliminating moisture source Best solution is eliminate both sources through selection of non cellulous (wood or wood by products) materials and preventing moisture

16 C - Moisture & Mold Star Bulletin April 22, 2003 Hilton sues tower builders : for $56 million for mold infestation for the following causes were listed in the article: 1. Tower design acted as a giant vacuum that suck in humid outside air because of low internal pressure. 2. Improper building mechanical system and building envelop that resulted in no control over the tower s humidity. 3. An exterior wall finish that did not server as a good barrier against moisture. Finishing system and sealant were not designed and installed according to industry standards and manufacturers guidelines. 4. Lanai doors that leaked outside air into rooms

17 C- Moisture & Mold Methods for controlling moisture & mold: Proper selection of materials Breathe able and not cellulose (wood by products), breathe able interior coatings, ceramic tile flooring, silicone enhanced self cleaning exterior finishes, paperless drywall, ceramic tile shower enclosures and backsplashes, aluminum cabinets, etc. Design of mechanical systems to handle also control indoor humidity and controlled ventilation. Proper architectural detailing, specifications and construction practices Proper locations of vapor barrier & preventing the second vapor barrier

18 C- Moisture & Mold This South Finegayan housing unit was closed up & AC turned off creating perfect conditions for mold growth. There is no dehumidifier system that would have solved the problem

19 C- Moisture & Mold Prior to renovation of this housing unit near Guam Naval Hospital, the AC was turned off, the housing unit interior & exterior doors were closed and the windows were closed and there was a water leak. This created a perfect environment for mold. A small dehumidifier sitting by the kitchen sink and using the sink drain for the condensate would have helped. Renovation project should include mold abatement costs and specifications

20 C- Moisture & Mold The photo shows a square black mold shape that was behind a remove st. st. backsplash for the stove. The non breathable stainless steel back splash created a second vapor barrier. Particular attention to preventing second vapor barriers that traps moisture between the first vapor barrier is essential to preventing moisture and mold problems. All interior surfaces must breathe to prevent trapping moisture and creating 2 nd vapor barrier

21 C & D- Moisture & Mold This photo shows the use of ceramic wall lltile back splash hbehind dthe stove. The tile grout prevents this back splash from becoming a second vapor. Also notice the ceramic tile floor and wall base on ground floor concrete slab where the grout breaths and flooring is resistant to flooding and moisture from the concrete floor. Installing VCT is a challenge in Guam due to the moisture in the concrete reacting with the VCT adhesives

22 C & D- Moisture & Mold The window rough opening is not sealed properly to prevent water from going under the sill and down into the furred out wall below. (Install windows according to ASTM E 2112) A&Es say concrete cracks and windows leak. The old housing exterior wall construction had no furred out walls and you could just wipe off the mold. However, with the new energy requirement that require furred out walls for insulation and hides the mold growing inside the wall cavity, the furred out walls will have to be demolished and then rebuilt at a lot more costs, time and family displacement

23 C & D- Flashing at Windows & Doors Window & door rough openings must be properly flashed prevent water from going g to exterior wall interior furred out cavities. Liquid flashing with fiber glass mesh method (shown), self adhesive flashing tape or designing concrete sill cap to cover the wall cavity are solutions. This Guam problem has occurred in housing, schools & other Government facilities. This is a very important when you consider the number of windows, and potential for mold from typhoon wind driven rains that occur on Guam

24 A & C & D- Moisture & Mold G90 light gage steel framing Spray foam insulation on the interior face of the exterior walls and under side of roof deck helps to create an air tight enclosure and meets UFC pressure testing requirements for LEED & Energy Star. G90 light gage steel framing with clips holding framing away from concrete wall, spay foam insulation and paperless drywall creates a good moisture and mold resistant interior side of the perimeter walls. Consider not using wall insulation due to mass of the exterior walls (minimum 6 thick concrete walls) to prevent rough use damage, hidden moisture and mold problems allowed by ASHREA 90.1 & possible cost savings

25 C & D -Moisture & Mold Both the exterior wall coatings and roof coatings have silicone enhancements that will self clean in rain and mildewcide additive to help prevent mold growth, to reduce maintenance and unsightly appearance

26 C & D- Moisture & Mold AC Diffuser Showing Mold Solution: Design AC horizontal & vertical ductwork access so that ductwork can be cleaned, contractor to provide a ductwork cleaning plan that works, contractor to close off ductwork openings during construction, contractor to clean duct system and change filters prior to turn over, provide UV lights at condensate pan, clean duct work and change filters periodically. No insulation i should be in duct work

27 C & D- Moisture & Mold Select materials that are not a food source for mold and for termites. Examples of non-food source are paperless p drywall, non cellulous spray on foam insulation, aluminum cabinets, non cellulous (wood) products, G90 light gage steel interior framing, ceramic wall and floor tile, plastic trim, solid surface window sills, plastic medicine cabinets, coated wire shelving systems and so forth. Prevent a second vapor barrier that traps moisture & leads to mold between the exterior first vapor barriers. All interior surfaces and materials must breathe. Seats, key and lap joints in concrete for envelope, door threshold, window sills, etc. to prevent wind driven rains having direct joints paths into facilities

28 E Sustainability Renewables Guam s typhoon challenges and technology not ready: 1. Solar hot water and crystalline PV ground mounted panels are rated for 130 mph wind speed and does not meet Guam s wind speed requirements. 2. Building integrated PV (BIPV) adhesive does not meet Guam s wind speed requirements. Near future hope: 1. Design research into using integrating manual pull down storm shutter technology to cover panels, protective walls and framing to meet Guam s wind speed requirements. 2. BIPV research and development of a 200 mph rated wind speed adhesive that would meet Guam s wind speed requirements. BIPV would then be used on roofs and other surfaces. EISA 2007 Federal Mandate of 7.5% Renewables