HSCI 453: Health and Physical Aspects of Housing
ENVIRONMENTAL DIVERSITY
Different geographical areas with different climates will demand different types of structures. There is not one structure type that is superior for all environments. For example, basements are typically found in areas with relatively cold winters and a deep frost line. The frost line is the point in the soil where the ground above freezes but the ground below does not. The basement is actually the building’s foundation and is built below the frost line to protect it from damage due to the expansion and contraction of soil with the outside temperature. Igloos provide maximum volume inside with the best supportive structure while also providing insulative properties. Thick walled adobe structures utilize passive solar properties, which allows heat from the sun to be conducted through the walls at a very slow rate. In tropical areas with warm humid climates thatch huts have been used to allow for airflow through the structures to prevent the growth of mold and fungus.
HISTORY OF HOUSING
The first housing policies in the U.S. were made during the colonial period. Laws were passed to reduce fire hazards. In Plymouth, no thatch was allowed on structures; in New Amsterdam, no chimneys; in Charleston, no wooden buildings. Other laws were passed to discourage low income residents and to keep neighborhoods clean: in Pennsylvania, no mud shelters; in Boston, outhouses were only allowed in private yards; in New Amsterdam, no littering allowed.
Tenement or "box housing" was designed to hold as many people as possible in response to massive immigration. The First Tenement Act in 1867 required:
each room must have an opening to external air. This can be via an opening to a hallway or other room
fire escapes
roof in good repair
banisters on stairs
minimum of one toilet for every 20 people
all infectious diseases must be reported to the board of health
The Second Tenement Act in 1879 required:
running water on each floor
each room must have a minimum total of 122 feet of window space opening to the outside air
Two prominent books were written regarding housing. Germ Theory of Disease- had a major impact for the health dept. Model Housing Law- wish list for perfect housing conditions. These books led to the Tenement Housing Act of 1901 which required privacy, running water & toilets in each apartment, all rooms must have a window to outside air, buildings must be inspected by a government agency.
WWI
The Multiple Dwelling Act was passed during the depression of 1929. It eased housing regulations to help people who didn’t have money to make repairs. Home ownership decreased so President Hoover created the Federal Home Loan Bank Board which loaned money to member institutions. The institutions then loaned money to people buying houses. FDR established the Homeowner’s Loan Corp. to buy people’s mortgages if they were threatened with foreclosure. The FDIC was created to stop a run on the banks.
Housing Programs
Steps in developing a plan:
Determine health problems in an area
Survey existing conditions
Prioritize tasks
Plan of Action
Develop codes
6 items that must be in a code:
Definition of terms
Administrative Procedures
Substance of Code
Basis for legal action
Enabling Conflict and Constitutionality Clause (tougher law applies, unconstitutional part can be voided without voiding the entire code)
Enforcement Activity
APHA standards are 1.5 people max. occupancy per habitable room
Substandard Dwelling- doesn’t comply with minimum standards
Slum- Area where substandard housing predominates
Blight- Section of city that’s undesirable for living or working
BUILDING A HOUSE
Factors to consider when deciding on a building location:
slope
drainage
axis- direction parts of house will face
view
privacy
access
water supply
building permit
A sill is any bottom board. Don’t let wood touch the ground or it won’t last long. Using treated wood for a sill keeps termites from penetrating it. A building’s foundation must be built to code or serious problems can develop. The footing is a building’s foundation and consists of a concrete pad that supports the weight of the structure and contains anchor bolts to secure the walls in place.
Partitions- inside walls
Bearing wall- perpendicular to ceiling joists, supports the ceiling
Runs- pipes and wires inside walls
Romex wire- 3 wires in a sheath, must be concealed in a finished house
Electricity- houses in the U.S. usually use AC, 60 cycles/sec = 60Hz. 120 Volts used in houses. Amps x Volts = Watts; V = A x Ohms
Wires - bare or green = ground; black and red = hot; white = neutral
Heat:
Operative temp. = (air temp. + mean radiant temp.) / 2.
Heat capacity: Energy in BTU’s required to raise temp. of 1 lb. of any substance 10 F. The heat capacity of water is 1 BTU, most other substances are below 1.
Specific Heat: ratio comparing the heat capacity of a substance to water. For example, the specific heat of sand is 0.2/1= 0.2.
Conduction- transfer of heat by touching.
Convection- transfer of heat through air.
Radiation- direct electromagnetic rays.
Poor heat conductors are the best insulators.
Black body radiation- theory describing any body that absorbs 100% of incident radiation and re-radiates 100% of it as heat.
Emissivity- ability to re-radiate heat. A value of 1=100% radiation.
Q=e[0.173 x T4 )/ 100,000,000] Q= total energy emitted in BTU’s/ft2/hr; e= emissivity; T=absolute temp.= 0F+460
R= d/k = insulating value; d= thickness, k= thermal conductivity; higher R value is better
U= 1/(R’s = heat flow through substance in BTU’s for 1 hr. through 1 ft2 when the temp. differential is 10F
Heat Loss = UA (TI-TO)T
A=square feet
TI = Temp. inside
TO = Temp. outside
T= Time
Plumbing
Goals: Provide potable water and prevent cross connections. The Uniform Plumbing Code has requirements for pipe size, fixtures, exams for plumbers, inspections.
Valve stops are used to control water flow: a corporation stop is used to tap into a water main, a curb stop is used to regulate flow into a structure. Galvanized pipe corrodes after about 20-25 years, copper lasts longer.
The P-trap under a fixture stays full of water to prevent sewer gas from entering the structure, also collects objects that are dropped. A clean-out provides access to the sewer pipe.
Gas pipes are colored black or green
Weather
Adiabatic lapse rate: temp. decreases as elevation increases
Environmental lapse rate = 3.5 0F decrease per 1000 ft. elevation gain
Sound
Three ways to reduce sound:
Eliminate it
Isolate it: move away from it or surround it
Insulate: keep it from traveling
Solar Energy
The amount of solar energy hitting 1ft2 of land = 2500 barrels of oil/day
Solar collectors capture about 40% of solar energy = ~1500 BTU’s/ft2. For example, the amount of solar energy hitting 700 ft2 = 700ft2 x 0.4 x 1500 BTU’s/ft2 = 420,000 BTU’s
The South and East sides of a house receive the most sun and warmth. During a winter experiment when the south side of an experimental house was made almost entirely of glass, the inside temp. was ~500 warmer than the outside.
A solar flat box uses a passive design to provide warm air for a structure.
Eutectic salts are used to surround some water heaters. They melt at 900 F. As they re-crystallize during dark periods, they give off heat and keep the water warm.
Lighting
Foot candle- illumination given by one standard candle one foot away from the source.
Lumen- quantity of light required to illuminate 1ft2 to the intensity of 1-foot candle.
Light is measured in Foot-Lamberts = 1.25 x (reflected light in ft. candles)
Reflective surfaces:
Specular- smooth surface with the angle of incidence = to the angle of reflection.
Matte- rougher surface where light reflects at different angles. This is easier on the eyes.
Forms of Lighting:
Direct = 90-100% directed downward-most efficient but hard on the eyes.
Direct indirect = directed downward but is diffused with a covering so you can’t see the bulb.
Semi-direct = 70-90% directed downward - least economical but best to work under.
Indirect- 90-100% directed upward.
CONTAMINATION PROCESS
Inefficient pilot lights can release natural gas and CO which can cause headaches, nausea, and malaise.
Fireplaces can release gases into the house.
Outgassing is a form of evaporation of solid chemicals that aren’t bonded perfectly. These contaminants can be absorbed and adsorbed by your body.
Electromagnetic Fields (EMF’s) travel like waves from electrical items. EMF’s change cells biologically but there is no consensus on their health effects. They may cause some types of cancer.
Indoor Air Quality
Formaldehyde is found in many parts of a building including the insulation, duct work, furniture, carpets, and adhesives. Formaldehyde outgassing can cause insomnia, asthma, and irritation to the eyes, nose, throat, and lungs.
VOC’s: hydrocarbons that evaporate at room temp. They are found in solvents such as cleaning agents. They can affect the CNS, irritate the skin and lungs, and cause kidney & liver damage. Symptoms of exposure include eye and skin irritation, dizziness, violent headache with nausea, and heart arrhythmia’s.
Phenols are found in cleansers, air fresheners, perfume, floor wax, mouthwash, and saucepan handles. Symptoms of exposure include rash, peeling skin and acne.
CO is released into a structure from unvented gas appliances. Symptoms of exposure include blurred vision, loss of judgement, headache, and nausea.
Ozone from electrical appliances irritates the respiratory tract, causes visual problems and lung irritation.
Asbestos particles can be found in construction materials used through the 1970’s. Fibers stay in lung tissue and cause irritation after 15-20 years.
Radon can enter a building and cause cancer after appx. 15 years. The radon decay particles (RDP’s) are most dangerous, not the actual radon. The EPA developed a radon survey program to address indoor radon hazards. The EPA action level is 4 picocurries/L air. Each house can have different levels. It is not a hazard in outdoor air. The alpha particles are very destructive in soft tissue like the lungs. 1 pc RN/liter air = 2.22 disintegrations/min.
RDP’s are measured in working levels (WL).
1 WL= RDP’s from 1 liter air containing 100pc of radon
100 pc = 0.5 WL’s in the air due to 50% plate-out of particles on the walls, etc. Dynamic equilibrium is achieved when RDP’s lost = RDP’s produced.
Dynamic equilibrium = Equivalent ratio = (WL value x 100)/RN conc.
This takes about 12 hours to achieve in a building with all doors and windows closed. The minimum standard radon test for real-estate purposes takes 48 hours.
About 1-4% of radon enters a house through the soil by diffusion. It can enter through cracks in a concrete slab. Most (85-90%) radon enters from soil air entering the house. This can be fixed by digging a hole through the slab and installing a fan to pull RN from the soil up and out an exhaust pipe instead of into the house.
Radon Measurement methods:
Charcoal Canisters – RN diffuses into charcoal and can also diffuse out, so it is not always a very accurate test, but it is ok for a survey.
Alpha Track detector- measures decay of RDP’s, test takes 90 days to 1 year.
Continuous Read Monitoring (CRM)- extremely accurate, measures the RN itself.
Natural Gas:
About 1/3 of all gas used goes to pilot lights. Small amounts of natural gas are always entering the kitchen. A gas oven being used in an unvented kitchen for 1 hour produces CO and NOx levels about 3x those of LA smog levels.
Solution: Get a pilotless stove and perform proper maintenance. Spider webs can develop in gas lines and need to be cleaned out periodically. Gas stoves may need to be adjusted to burn more efficiently. Proper adjustments can improve performance from a low efficiency level of 40% to a maximum efficiency of 80%.
Dust:
Can lead to major health problems for people
~500 particles/ cc air = "clean air"
~50,000 particles/ cc air = city air
Particles can pick up things like insect fragments, mold, cotton, feathers, wool, bacteria, and spores. These particles and their contents can cause rhinitis, an irritation of the nose, eyes and throat.
Dust mites are found in carpet, upholstery, bedding and drapes. Many people are allergic to mites. When the mites die in winter their bodies decompose and become aerosolized and people can then inhale them.
Mold:
A link has been found between mold, fungi, spores and cancers. Mildew grows in moist environments such as on cold water pipes, in showers and in dryer vent tubes. Mold can cause mucous membrane irritation, digestive disorders, asthma attacks, hayfever and depression.
Alternaria is a mold spore with a large antigen mass that causes allergic reactions and mucous formation.
Aspergillus fungi can colonize in the human airway. Dust spores in outside air usually number around 1,000/m3 air. Windy days can produce ~50,000 spores/m3 air. Normal indoor conditions contain ~10,000 spores/m3 air.
RENTAL PROPERTIES (IE. APARTMENTS)
The owner or manager is usually responsible for maintenance and making repairs. Rental agreements usually are on a month to month basis. A lease is for a fixed term like 6 months, etc. Oral agreements are legally binding but written agreements are recommended.
Common charges for rentals:
Security Deposit- can only be used to repair damage, make up for a default in payment, clean the premises, restore stolen property. It can’t be used to repair normal wear and tear like repainting, replacing carpets, etc. If it isn’t returned, the landlord must issue a written itemized receipt of what it was used for.
Holding Fee- money paid to keep a room so no one else will rent it.
Credit check
First and last month’s rent
Total move in amount can’t exceed 2 months rent, excluding the first month’s rent. If furnished, a landlord can charge 3 months rent.
Eviction- must allow tenants 60-107 days to legally be evicted from a property.
The landlord can only legally enter the house:
in case of emergency
to make repairs
to show new renters (if you aren’t home)
when invited