Mech/Elec ALS Lesson One - Basic Thermal Processes: Heat Load Calculations - Conduction Below Grade, Infiltration Load, Cooling Load, Etc.

Mech/Elec ALS Lesson One - Basic Thermal Processes: Heat Load Calculations

- Conduction Below Grade, Infiltration Load, Cooling Load, Etc.

It is difficult to determine what value to use below grade for the outside temperature since it varies with depth and moisture content

Loss through basement walls and floor slabs is comparatively low.

below grade wall values are taken from a table based on ground water temperature which is assumed to be same as the average annual air temperature

below grade loss = total area X factor from table

Infiltration = flow of air leaking through cracks in building skin, window frames, walls, sockets and switches, etc.

Outside air leaks in, replaces internal air and needs to be heated

Heat required is called "infiltration load" Qi

Calc'd in two steps:

1. determine amount of air infiltration

Two methods, "air change method" OR "crack method"

Air change method = need to know air changes per hour, measure or estimated, good method for tight buildings

Crack method = number of linear feet of crack or joint in all the windows in space, then look at result on table

2. use infiltration amount from step 1 to solve infiltration load (qi)

Infiltration load calc's

Qcfh = LF x CFH/lin.ft.

Qi = .018(Qcfh)(T-inside - T-outside

Total heating load = sum of all loads considered

Heat Load Calc = Qtotal = Qc + Qs + Qi

Where

Qc = conduction(expressed in Btuh's

Qs = Conduction below grade

Qi - infiltration

Temp. Gradients = usefull to calc. temp within wall to avoid freezing and bursting pipes for example.

Cooling load calc's =used to size cooling equipment, many factors must be included

Sources of heat gain to be considered:

Occupants(Qp) - number of people & activity, 450btuh's at rest, 2500btu's for heavy activity,

number of people X btuh per person = people load

Lighting(Ql) - heat in proportion to wattage, 3.4 X Wattage = lighting load

Equipment(Qm) - many different ways to calc. btuh's, wattage like lighting, motor horsepower

Cooling Load Temperature Differential (CLTD) - heat gain through walls and roofs

1. determine wall/roof classification or group

2. determine base CLTD from the time of day, wall type, wall orientation and wall or roof color

3. adjust CLTD based on the temp. history of last 24 hours.

Radiation through windows: (qr or SHGF-Solar Heat Gain Factor)

insolation = radiant gain through glass

several methods to calculate: Intensity of direct sun X glass area X percentage transmitted = SHGF

Percent transmitted compared to clear glass is the Shading Coefficient (SC).

There are tabulated SC values

Best to stop direct sunlight OUTSIDE the building, using fins, overhangs or awnings.

Prevents heat gain on interior, IE. interior blinds would block light but heat up and radiate heat. If required, lighter colors are better since they absorb less.

Mech/Elec ALS Lesson One - Basic Thermal Processes: Heat Load Calculations - Conduction

Building Heating load = Sum of all losses through the building skin

Conduction Formulae

Same formula for roofs, walls, windows or doors

Any given instan / instantaneous version

Determines the case at a particular moment, usually called design day, this day is colder than 98% of the other days, if equipment can handle the load for that day then other days will be taken care of.

Heat flow = product of conductance of the assembly / the U value X Temperature difference between inside and outside X exposed surface Area

Qc = U(A)(T_inside - T_outside)

Any given day / degree day version

Used to compare two alternatives over a lobger period of time.

able to analyze a payback period on investment, i.e., how many years of reduced energy costs it would take to pay for the increase in insulation

Qc = U(A)24(DD)

DD = degree days

Qc = Btu's

One degree day = any given day where temp. is one degree below 65deg

Two degree day = any given day where temp. is two degrees below 65deg

65deg's is the mean reference

For heat loss, days over that temp are disregarded.

This last equation gives the ability to calculate the degree days for a particular locality over a period of time, even an entire winter for heat loss.

Mild winter = 3,000 degree day winter

Severe winter = 7,000 degree day winter

INstantaneous version fo Qc is used to determine the case at a particular moment, ussually called the design day.

Design day = a day colder than 98% of the days experienced in a given climate. If the heating equipment and plant are sized to keep the building warm on that day, they would be sufficent for the other 98% of thedays also.

Degree day version of the formula for Qc may be used to compare two alternatives over a period of time. Possible to determine a payback period on an investment.

Study time: 5/24 9:15-9:45pm 0.5 hours

Mech/Elec ALS Lesson Three - Mechanical Equipment and Energy Codes: System Distribution Types - Forced Air Systems

Forced air system = sidtributes heated or cooled air around a building using supply ducts.

return air = through return ducts or space above ceiling called a plenum

Supply ducts usually run above ceiling to ceiling or wall registers

Occupied space can be a return plenum too, undercut doors, door registers and cold air registers between two floors are sometimes used to allow air to return to the unit

Air into the plant usually mixed with interior return air and fresh air from exterior

fresh air intake = at exterior of building, ducted connection to plant, away from cooling tower and other exhausts

outside air = requires warming or cooling

return air = must be cleand or filtered

air changes = number is required by code or good practice, must be provided despite differing thermal load requirements

Supply fan = pushes air from the plant through ductwork, must have sufficient flow volume to give  sufficient pressure to overcome friction in the duct.

Pressure = expressed in terms of "static head of water", which is the height of a column of water which could be lifted by the pressure.

infiltration elimination = run supply fan at greater rate than sum of the return air fan rate plus the leakage rate of the building

deck temperature = also know as equipment tempurature, temp. of air as it leaves the equipment room

Insulate ducts to prevent cold or hot temp. loss (especially cold)

Exterior insulation = for temperature control

Interior insulation = for sound control

decrease noise transmission of fans and plants:

isolate on springs, rubber pads and concrete pad to mount to.

duct connection = rubber or fabric, pressure and flow maintained but connection is flexible

Simple forced air system:

Single duct system = mostly residential, constant air flow (constant volume), runs until temp. reaches thermostat setting

Can't heat or cool rooms separately, heats & cools simultaneously

damper = metal flap on diffuser used to shut off or reduce airflow.

system is problematic if greater need for ventilation than heat

Electric reheat system = variant of previous system

Air is cooled, electric resistance heater is placed in duct upstream of diffuser that needs heat,

very inefficient, only good in hot climate where heat is rarely needed

Double duct / dual duct system:

Combination or two single duct systems, one carries heated air, the other, cooled air

requires twice as much duct space

can heat one room but cool another

airflow rate is constant

but

amount pulled from each room is controlled by dampers and mixed in a mixing box which is controlled by the thermostat

Ideal for linear buildings requiring different thermal conditions

Multizone system:

reduces amount of ducting, mixing boxes are inside the mech. equipment room

pre-mixed air is sent to each zone

efficient for square building plan or a smaller few zone system

Fan coil system:

MOST EFFICIENT, high first cost (due to plumbing)

can heat and cool simultaneously

Constant volune of clean and conditioned air is supplied by a single duct.

Chilled water pipe & Hot water pipe

Each zone has a unit with a fan and two coils, one hot and one cold

Variable air volume (VAV) system:

MOST COMMON EFFICIENT SYSTEM

single duct system, may be three or four separate single duct systems serving the number of zones required

Zone makes up a group of rooms

flow rate may be varied instead of constant

Air to a zone is at a given same temp. amount of heating or cooling is determined by air volume delivered.

Mech/Elec ALS Lesson Three - Mechanical Equipment and Energy Codes: System Distribution Types - Electrical & Hydronic Systems

System Distribution Types - Electrical

Simplest, lowest first cost, most expensife life cycle cost

only justified in mild climates where system is off most of the time

two electrical system categories:

radiant systems = radiant panels or wires embeded in ceiling, also baseboard heaters that heat up and cause convective air circulation

pros: turn on per location, objects heated not air, 

cons: electrical generation from combustion, therefore low efficiency, wasteful and expensive

System Distribution Types - Hydronic Systems

Hydronic systems = also radiant, hot water or steam circulates through registers or pipes embedded in floors, heat then radiates into space.

Baseboard heaters can use hot water and steam too.

Forced air can be added, which blows air past the heated coils, pipes or radiators

Different loop patterns:

Single pipe = single supply and return pipe, runs in series or partly parallel.

hot water circulates through each register(coil), first one is hottest with decreases down the line.

Low first cost, limited service distance since water would be quite cold at last register, more than five is not good

Two pipe (parallel) = separate supply and return pipes, water not mixed back into supply pipe after through register, keeps same high temp. at all registers

Three pipe = for heating and cooling one supply to cold coil(register), one supply to hot coil & one mixed return pipe

more expensive to operate since water must be re-heated or re-cooled since mixing changes the temp's instead of having relatively hot and cold water in separate return pipes, see next system

Four pipe = Separate two pipe system for cooling and heating resulting in four pipes. Separate supply and return pipes.

fairly constant temp's, more cost efficient

Mech/Elec ALS Lesson Three - Mechanical Equipment and Energy Codes: Plant Types - Heat Pump

Ching Viz Dictionary of Architecture

Heat pump:

A device that uses a compressible refrigerant to transfer heat form one reservoir to another, with the process being reversible so that it can be used for both heating and cooling a building.

ALS

Running system in reverse brings heat from outside into the building.

the refrigeration cycle moves heat around

1 Btu of energy can move 2-4 Btu's.

Normal boilers run at about 80% effeciency

Efficiency = energy delivered / energy used

Coefficient of performance (COP) = energy delivered / energy used

vary between 2 and 3, typ. being 2.3

compressor placed in building is beneficial, then friction heat can be a heat gain

Mech/Elec ALS Lesson Three - Mechanical Equipment and Energy Codes: Plant Types - Refrigeration Cycle

Topic:

Plant Types - Refrigeration Cycle

Plant Types - Refrigeration Cycle

Air conditioning = relies primarily on the refrigeration cycle which originally used a fluid called FREON

Freon = from the chorofluorocarbon or CFC gases family

Excerpts from USGBC article "Greening your Refrigerants — Saving the ozone layer and saving money"

"Under the Montreal Protocol U.S. CFC production ceased in 1995. Consequently, specification of non-CFC building equipment is now standard and CFC-based refrigerants are no longer available in new equipment... ...A common alternative to CFC refrigerants is their chemical cousin, hydrochlorofluorocarbons (HCFCs)...  ...they still cause significant ozone damage...  ...HCFCs will be phased out in the United States by 2030...  ...hydrofluorocarbons (HFCs), that are considered "greener" than either CFCs or HCFCs. A key chemical difference is their absence of chlorine atoms, which means their ozone depletion potential is essentially zero. On the downside, they still have significant global warming potentials (like CFCs) and are somewhat less thermodynamically efficient than their predecessors..."

General description

Gases ar circulated in a closed, pressurized tubing loop, Pressure is varied by a pump and a constricted section of tubing or a valve, causing changes in temp., evaporation and condensation.

Condensor = Pump increases pressure on the gas, causing condensation, releasing latent heat of evaporation

next

Evaporator = gas passes through an expansion valve(or constriction in the tubing) and experiences a pressure drop on downstream side allowing the liquid to evaporate, absorbing the latent heat of evaporation from its surroundings.

Due to extreme pressure differences, Condensation creates a high temp. and loses heat to it's surroundings and Evaporation creates a very low temp. absorbing heat from its surroundings.

Heat exchanger coils (like car radiator) = both evaporator and condensor are made up of them

evaporative chiller / cooling tower = located outside building and dissapates heated water from the condenser to the outside air, there is a constant loss of water which must be added

blow down = valve in base of cooling tower which allows minerals and dirt to be drained out for cleaning

Evaporator cycle / cooling loop:

coil takes heat from water or air down to 50 - 55deg F, then circulated around buliding.

Outside air may be used directly when cool enough.

cold clean pond water may be used in some climates instead of chilled refrigerated water cooling without the evaporative chiller, know as economizer cycle.

Mech/Elec ALS Lesson Three - Mechanical Equipment and Energy Codes: Plant Types - Boilers and Chillers

Topic:

Plant types - Boilers and Chillers

GENERAL

Heating, Ventilating and Air Conditioning (HVAC) mechanical equipment is used to supplement and control a buildings thermal loads.

Two basic elements:

Plant = Creates the warm or cool water or air, usually in a central equipment room or location

Distribution = mechanism or system which delivers the heated or cooled air or water to the necessary zones or rooms in a building.

PLANT TYPES - BOILERS AND CHILLERS

Early plants = for heating only by hot water or steam

Air conditioning = when developed, plants became sources of chilled water or cooled air also

Heated water  = Fire under a tank or heat exchanger tub, called a boiler

Exhaust flue = required to vent combustion byproducts

external combustion air = brought in from outside instead of wasting warmed interior air for the process

forced air furnace = compact version of boiler, air is moved through a manifold warmed by burning Oil, Natural gas or propane. 

Gravity feed = furnace in basement and hot air would rise into house above, air moved too slow

Fan = introduced to place furnace anywhere, like attic, requires return air and ducts

Downdraft furnace = air flow is downward through the furnace reversing the convection

lowboy = a furnace that is reduced to five feet high allowing a more compact location

Mech/Elec ALS Lesson Seven - Water Supply And Drainage Systems: Water Pressure - Lift & Friction

topics:

Water pressure

Lift

Friction

Water pressure - Lift

To supply  proper flow rate to upper stories, water must be lifted which requires pressure.

psi = pounds per square inch

static head = inches or feet of water that can be supported by a given pressure

one psi can lift a column of water 2.3 feet high, e.g., 10 psi can lift water 23 feet

additional pressure is needed to operate the fixtures at the highest level.

Calc example:

8 story building

14 foot floor to floor height

toilet requires 15 psi to flush

total lift = 8 stories X 14 feet per story = 112 feet

if 2.3 feet is equivalent to 1 psi, 112 feet is equivalent to 112/2.3 = 48.7 psi

Required water pressure

= 48.7 psi for lift + 15 psi for flush

= 63.7 psi

If water pressure from street is less than total required then other mechanical methods must be used to acheive proper pressure( this will be addressed shortly)

Converting 

1 psi = 2.3 lift feet

then

.433 psi = 1 lift feet

faucet = 

Mech/Elec ALS Lesson Seven - Water Supply And Drainage Systems: Materials and Methods - Steel, Copper & Plastics

topics:
Materials and Methods
Steel
Copper
Plastic


Mat. & Meth.
Many materials have been used for piping, even lead in the past because it was so easily malleable(bendable).

Steel
Untreated steel used to be called black iron due to its color, it easily rusted and was quickly replaced with galvanized steel pipe which has a thin layer of zinc bonded to the surface making it fairly rust-resistant.
Wall thicknesses were standardized by schedules, schedule 40 is the most common.
Steel pipe is typically mechanically joined by threading and collars.


Copper
Often used for supply and considered the best for this use.
Does not rust and is corrosion resistant, oxidation builds up a thin film which protects the copper.
Wall thicknesses are typically less than in other materials.
Three categories:
Type K (thickest walls)
Type L (Medium walls)
Type M (thinnest walls)
Most commonly used per MEEB & Archiflash is Type L.

Joining by a form of soldering called sweating.
Flux is applied to surfaces to be bonded, sections are heated so that flux melts, then pieces are put together having sleeves or elbows that fit over one another.
when cooled, the pipes are structurally joined and completely sealed.
Process easily reversed by reheating.


Plastic
Major competitor for copper pipe.
Two types are PVC & ABS
PVC used for supply, white with blue lettering
ABS used for drainage, larger, black, with white lettering

Does not corrode but deteriorates when exposed to ultraviolet light.
Do not expose above ground or outside walls.

Joining with sleeves using solvents or cements
Prime surface, let dry
apply cement or solvent
slide joint together.
process is NOT reversible.
Changes are made by cutting and replacing.

Mech/Elec ALS Lesson Seven - Water Supply And Drainage Systems: Supply - Hardness & Carcinogens & Disease (Oh My!)

Topics:
Supply-Hardness
Supply-Carcinogens
Supply-Disease

Hardness
Water seeping into the ground dissolves minerals from the ground
Commonly Limestone and/or Calcium and/or Magnesium.
This creates hard water.

Usually not harmfull to humans but harmfull to plumbing.
These minerals leave deposits on pipe walls eventually clogging the flow.

Also a problem for heat exchangers like hot water tanks and hydronic systems.
Deposits choke the flow or insulate the pipe so heat is not transferred.
A metal Anode can be inserted into the tank to collect the deposits instead of on the walls.

Hardness interferes with cleaning in the way soap and detergents react with the water.
ions already dissolved in the water from the minerals can prevent additional dirt from being dissolved(cleaned).
The minerals can coagulate with the soap to form a soft paste in the plumbing

Water softening is the process used to reduce the amount of dissolved minerals
Either remove the mineral ions or combine them with something that will not solidify when heated.
Zeolite or ion exchange process
Two tank process, first contains Zeolite mineral, second contains salt crystals


Carcinogens
These are cancer causing agents that must be tested for and avoided.
Largely but not limited to PCB's (Poly chlorinated biphenyls), DDT and other insecticides and asbestos fibers.


Disease
Bacteria and viruses
Usually comes from improper disposal of human and animal waste or other organic materials that decay and are a source and a breeding ground for disease-causing bacteria and viruses.
Traditional treatment = settling out contaminants
Adding alum causes coagulation and sediment to settle out.
Chlorine can be added to kill or reduce bacteria. At 0.5 ppm (parts per million), Over 1 ppm, you get a distinct chlorine taste.
Fluorine can be added to improve rooth decay resistance.
Oxygen added if enough is not already present in the water, by passing through a spray or waterfall. Oxygen makes it more fit for consumption but also increases rate of rusting in iron based (ferrous) fittings.

Mech/Elec ALS Lesson Seven - Water Supply And Drainage Systems

(Attacking the lessons out of order, I joined an online study group, we will be covering a topic a day, I will get back to lesson 1)

Topics:
Intro
Supply-Acidity

INTRO
Supply & Waste
Supply = provides clean, clear, potable(drinkable) water for drinking, cooking, washing, industrial process, etc.
Lines are under pressure and can run vertically, usually in smaller pipes than for waste.

Sanitary Waste = removes contaminated water and is usually not under pressure, commonly drained by gravity requiring sloped piping.

Storm drains = for rainwater, also drained by gravity and usually have larger piping.

All systems are separate from eachother.

SUPPLY - Acidity
Water needs to be clean clear and potable(suitable for drinking).
Potential contaminants to be considered:

Acidity: rainfall is slightly acidic measured by the pH, higher acidity = lower pH number
Neutral = pH of 7
Slightly acidic = pH of 6.9 to 6.0
Very acidic = pH of 5
A basic or alkaline solution = pH above 7 up to 14 being the most alkaline or "basic" solution
(online resource for more info on pH and explanation of basic/alkaline)

Natural acidic state of rain water has been worsened due to air pollution, especially sulfur and nitrogen compunds.
These combine with moisture to form sulfiric acid (most common) or nitric acid (less common)

This has raised the acidity of many fresh water lakes where no or few fish are able to survive any longer.

Problem for plumbing systems:
Higher acidity can corrode metal pipes.
Water is less potable
Therefore, Rain water and surface runoff is less healthy than water absorbed and partially filtered through the ground.

Mech/Elec ALS Lesson 1 - Basic Thermal Processes: Radiation, Convection, Conduction & Latent Heat

Basic heat transfer Processes

Temperature = a measurement of stored heat energy but temp. is never transferred, onlyl heat energy is

Heat is sometimes transferred without a change in temp., such as a melting ice cube

sensible  heat = heat that causes a change in temp.

latent heat = heat that causes a change in state (like melting ice)

objects at the same temp. can store different amounts of heat, this storage capacity is called specific heat (Cp) which is measure by comparing it to the storage capacity of water.

British Thermal Unit (Btu) = Amount of heat energy required to raise one (1) pound of water by one (1) degree Fahrenheit.

So, specific heat is measured in terms of the number of Btu's req'd to change the temp. of a specific material by one (1) degree Fahrenheit.

Radiation

Radiation = Method  by which heat is transferred between two objects not in contact and NOT SHIELDED from each other.

Heat you feel from the sun is through heat transfer by radiation

Radiation always takes place but it usually takes place at a slow rate.

ALL objects  radiate at each other, even people standing next to one another.

Wavelength of the radiation is based on the temp. of the object.

Warm things radiate infrared (non-visible)

Really hot objects (like red hot steel) begin to glow in the visible spectrum

Glowing heat:

Red = Hot

Orange = Hotter

White = Hottest

The rate of radiative exchange is based on the surface temp. of the objects, the viewed angle and a property called emissivity.

The Emissivity (ε) of a surface is a property of the material and is usually the same as the absorptivity at any given wavelength.

Simple example is color = Black surfaces have higher emissivities and absorptivities than white or shiny surfaces.

Black heats up rapidly and cools off rapidly. Shiny surfaces heat up more slowly but stay hot longer.

Emissivity and absorptivity are often different between the infrared and visible spectrum.

Selective surfaces = surfaces which have a high absorptivity rate in one wavelength (usually solar) and low emissivity in another (usually infrared). 

Foil on the back of some insulation has a very low emissivity which reduces the radiative transfer across the air space inside the wall.

 

Transmissivity = measure of how easily  a material allows radiant energy to pass through it.

Glass has low transmissivity since it does not allow infrared to pass through like in a greenhouse.

Sunlight  (a short wavelength and visible portion of spectrum) passes through the glasse heating up materials inside, when the materials heat up (called reradiate) they heat up in the infrared spectrum which cannot pass through the glass and becomes trapped heat energy.

Viewed angle = depends on the size of the surface and your distance from it.

Stand close to a meat freezeer, it occupies a large angle of view and you lise a lot of heat to it.

Stand across the room from it, it occupies a smaller angle of view nd there is consequently much less heat exchange (loss in this case)

Mean Radiant Temperature (MRT) = the average radiant temperature of your surroundings.

Device that measures MRT is called a globe thermometer.

Convection

Convection =  the heat exchange process which occurs only in a fluid medium, such as air or liquid.

Hot air rising is an example, it expands when it's hot, which reduces it's density and makes it lighter. The cool, heavier air falls, the warm lighter air rises.

Smoke rises in chimneys since it is warmer.

One Exception, water expands when it gets colder and only just before it freezes.

Convection occurs in rooms all the time, it's the only means of heat transger qhich is strictly directional, it never transfers heat downward, it can transfer horizontally by stirrin air but not as rapidly as upward.

Stagnation = when the top of a space si warmer than the bottom and the hot air rises and stays there.

Stack effect = difference in pressure in a vvertical space (positive  or outward at the top and negative or inward at the bottom).

Rising air pushes at the top and it pulls air in behind it , down below.

Can be a significant effect in office towers where elevator shafts act like smokestacks.

Thermal resistance values are different based on orientation of a surface (horizontal or vertical, floor/roof or wall), and based on the direction of the heat flow (up or down).

The orientaition is  more critical than the thickness.

The thin film of air which occurs next to a wall also provides a resistance, calculated as the inverse of the so'called film coefficient.

Conduction

Conduction = the heat transfer process which occurs when objects are in direct contact.

Non-directional, it transfers in any direction with contact.

Conduction occurs inside walls, transferring walls from the warmer side to the colder side.

Each material has a different conductivity and resistivity.

Resistivity = inverse of conductivity

Specific thicknesses of materials have a calc'd conductances and resistances.

The resistance (R) is calculated from the thickness (x) and the conductivity (k), using the following formula:

x / k = R

Insulation for example is specified by the letter R followed by a number, i.e. R-19 insulation has a resistance of 19.

A complete wall assembly has a calc'd conductance, which represents all the interactions of the internal materials, including some radiation and convection, this is called the U value.

The U value is the reciprocal of the sum of the resistances (1 divided by the sum):

U = 1 / (R + R + R + ... + R)

(to be continued...)

Study time: 5/12 9:00pm-10:15pm = 1.25 hrs

Conduction Continued...

Latent Heat

Viz. Dict. of Arch. (Ching) = The quantity of heat absorbed or released by a substance during a change in phase at constant temp. and pressure.

e.g., sweat evaporates and cools off the body by absorbing some of the heat by the change of state from liquid to steam, the change of state uses the heat energy.

phase change = when an element changes state like from liquid to solid, liquid to gas, etc., it either stores or releases energy, measured by heat transfer

-32deg F = freezing point of water

212deg F = boiling point of water

Pound of water at 212deg F requires 1,000 btu's to evaporate

study time: 5/24  5pm-5:45pm, 9pm-9:15pm

One Last Site Planning note (for now)

Basic math equations essential to Site Planning exam.

SLOPE PERCENTAGE
X=(1/12)100
X is slope percentage.

GRADE PERCENTAGE
G=(V/H)100
G is grade as a percentage.
V is vertical change in height.
H is horizontal change in distance.

Passed Building Tech. & Changing Exam Order

Recieved my pass letter for Building Technology yesterday!!!!!!!!!!!!
I thought I had passed it but you never want to be so sure until you get the pass letter.
Whew...
Ok, so on further review, I have decided to switch to only taking one more test before the end of June and taking the others in version 4.0.
So I will be switching to Mechanical and Electrical Systems since it is linked to Building Tech.

I realized by trying to take Site Planning and Pre-Design before the end of June I was needlessly putting both of those tests at risk for failure since my schedule for study time would have been much shorter than it should be.

Sorry for those that may have been following my Site Planning notes but I will pick it back up later.

Bye for now...