Passive House Design
Which three of the following methods are used to provide active heating through the ventilation air in a passive building?Select one or more: a. Air-to-air - ducted heat pump fan coil b. Air-to-air - ducted bio-char gassifier c. Water-to-air - hydronic duct coil d. Air-to-air - modulating exothermic reaction coil e. Air-to-water - hydronic duct coil f. Electricity-to-air - electric duct heater
a. Air-to-air - ducted heat pump fan coil c. Water-to-air - hydronic duct coil f. Electricity-to-air - electric duct heater
The four environmental characteristics that most influence indoor thermal comfort are:
Dry-bulb temperature, wet-bulb temperature, air speed, and surface temperature (MRT)
In bathrooms, exhaust-air grilles should be placed as close to the door as possible.Select one:
FALSE
Projects may only account for renewable energy generated on the building site to meet the Phius ZERO source energy limit.Select one:
FALSE
Projects must implement Electric Vehicle Ready provisions whether or not a parking space is required for the project.Select one:
FALSE
In a passive building enclosure assembly, an air control layer...
Limits airflow through assemblies and between conditioned and unconditioned spaced. May also serve as a vapor retarderer. Must leak less than 0.060 cfm per square foot of gross enclosure at 50 pascal
What of the following best describes general approaches to providing good IAQ
Source control, filtration, exhaust, dilution, and maintenance
Which two of the following factors are not required to calculate the amount of heating or cooling deliverable via the ventilation air? a. Ventilation rate b. Heating degree hours c. Temperature difference between incoming air and max or min air temperature after heating/cooling element d. Temperature correction factor e. Heat capacity of air at appropriate altitude
b. Heating degree hours d. Temperature correction factor
The following bulleted phenomenon are examples of what? Absorption of driving rain Splash back of rain at grade Capillary suction and capillary redistribution of groundwater Built-in moisture Vapor transport via air infiltration or vapor diffusion
Wetting Mechanisms
The source energy limit for residential Phius CORE projects is _________Select one: a. 6500 b. variable based on climate only c. 4200 d. variable based on occupant and unit density
d. variable based on occupant and unit density
Fossil-fuel combustion is allowed on-site for projects certifying to _________Select one: a. Phius CORE b. Phius ZERO c. Phius CORE REVIVE d. Phius ZERO REVIVE e. All of the above f. A & C only g. B & D only
f. A & C only
Dewpoint is characterized by the change of state from vapor to liquid. It is a common factor in moisture damage. Dewpoint occurs on surfaces, which must be cooler than the air containing vapor next to it. Vapor supply to the surface is usually by airflow but can be by diffusion.
false: dew point is the temperature the air needs to be cooled to (at constant pressure) in order to achieve a relative humidity (RH) of 100%
A passive building located in a mixed humid climate with cold dry winters and hot humid summers will typically achieve better comfort by installing an ERV rather than an HRV.
true
As the temperature and humidity increase in a building, you need to increase the volume of recirculated air to effectively dehumidify the space.
true
A home was designed with the following conditions:Slab on grade, 2 storiesExterior boundaries of footprint (to exterior of insulation) 30 ft x 50 ftHeight from bottom of sub-slab insulation to top of attic insulation 22 ftiCFA = 2700 ft23 bedroomsWhat is the minimum air-tightness requirement for this building under the Phius 2021 Passive building standard, expressed in:cfm per square foot of gross enclosure at 50 PascalsTotal cfm at 50 PascalsAir changes per hour at 50 PascalsEstimate that the net volume for the air-tightness test is 80% of the gross volume.(Select all 3)Select one or more: 0.05 cfm50/ft2 0.06 cfm50/ft2 0.08 cfm50/ft2 0.006 cfm50/ft2 400 cfm50 391 cfm50 321 cfm50 522 cfm50 1.19 ACH50 0.89 ACH50 0.6 ACH50 0.71 ACH50
0.06 cfm50/ft2 391 cfm50 0.89 ACH50
During a QA/QC visit to a Phius project site it has been discovered that the insulation contractor installed fiberglass batts instead of the dense pack fiberglass that was specified for the 2x6 walls. The R-value of the fiberglass batts is R-3.4 per inch, whereas the dense pack fiberglass spec called for R-3.8 per in.The gross square footage of the building is 2200 ft². The iCFA is 1800 ft². The exterior wall area is 1880 ft² The previously calculated annual heating demand with dense pack fiberglass insulation was 4.49 kBTU/ft² yr. The Phius annual heating demand limit for this location is 4.6 kBTU/ft² yr. The number of heating degree days is 6035 °F.day/yr.Part 1) What is the new specific annual heating demand for this project? Round to 4 places during the calculation and round to three (3) places for your final result. Part 2) If you added 2" of EPS at R-4 per inch to the modified assembly, would the project meet the Phius annual heating demand certification threshold?Select one or more: a. 5.352 kBTU/ft²yr b. 4.622 kBTU/ft²yr c. 6.165 kBTU/ft²yr d. 4.824 kBTU/ft²yr e. 5.987 kBTU/ft²yr f. Yes g. No
a. 5.352 kBTU/ft²yr f. Yes
When conducting an inspection of passive house project slab preparation prior to concrete pour, what are the four most important items the PHIUS+ Rater will review?Select one or more: a. Air barrier is installed to allow continuous connection of horizontal to vertical elements b. Radon mitigation system is installed properly, when applicable c. Under slab stone is even, level and compacted d. Air barrier is installed with joints and penetrations sealed permanently e. Under slab insulation is complete and continuous without gaps f. Reinforcing is properly placed g. Air barrier has no punctures or gaps and methods of reinforcement placement are used that will not allow punctures during the pour
a. Air barrier is installed to allow continuous connection of horizontal to vertical elements b. Radon mitigation system is installed properly, when applicable c. Under slab stone is even, level and compacted d. Air barrier is installed with joints and penetrations sealed permanently e. Under slab insulation is complete and continuous without gaps g. Air barrier has no punctures or gaps and methods of reinforcement placement are used that will not allow punctures during the pour
Heating degree hours are required to calculate which three of the following choices?Select one or more: a. Annual transmission loss b. Peak ventilation loss c. Peak transmission loss d. Annual Heat Demand e. Peak Cooling Load f. Annual ventilation loss
a. Annual transmission loss d. Annual Heat Demand f. Annual ventilation loss
What are the four best strategies for optimizing solar gains in Phius projects?Select one or more: a. Balance evaluation of useful winter gains against unwanted summer overheating b. Always place the window closer the outside surface of the wall c. Specify the majority of glazing on the south-facing façade d. Start with a glazing-to-wall percentage of less than 10e. Use 2 ft overhangs on all roofs f. Use the Phius window database to find SHGC recommendations for your climate g. Select the highest SHGC available h. Use WUFI Passive during design phase to select a building orientation and a window layout with the lowest energy requirements i. Utilize summer shading strategies such as exterior blinds, solar-reflective screens and deciduous landscaping elements
a. Balance evaluation of useful winter gains against unwanted summer overheating f. Use the Phius window database to find SHGC recommendations for your climate h. Use WUFI Passive during design phase to select a building orientation and a window layout with the lowest energy requirements i. Utilize summer shading strategies such as exterior blinds, solar-reflective screens and deciduous landscaping elements
In the Phius Passive Building standard, the air tightness metric is CFM / Sqft of enclosure area rather than ACH. This was done for the primary reason of addressing _______ and the secondary reason of addressing ________.Select one: a. Durability, Energy Savings b. Energy Savings, Durability c. Marc Rosenbaum, Wolfgang Feist d. Durability, Longevity
a. Durability, Energy Savings
You are the Certified Passive House Consultant (CPHC®) for a new passive house building in the Great Lakes area of the U.S., with a climate characterized as predominantly heating with some cooling. The minimum winter temperatures are similar to the Northeast U.S., but with more cloud cover.You're evaluating two different potential window upgrades to meet the project's performance criteria. The first potential upgrade is doubling the R-value of the windows. The second potential upgrade is doubling the glazing SHGC.Which upgrade will be more cost-effective? a. Glazing SHGC increase b. Window R-value increase
a. Glazing SHGC increase
When assessing passive building energy balance, transmission losses must be calculated for which three thermal bridge boundary condition "categories"?Select one or more: a. Perimeter thermal bridges b. Ambient thermal bridges c. 2-D thermal bridges d. Window psi-install thermal bridges e. Point thermal bridges f. Below grade thermal bridges g. 3-D thermal bridges
a. Perimeter thermal bridges b. Ambient thermal bridges f. Below grade thermal bridges
Thermal bridges that exceed ________ must be accounted for in a project's WUFI Passive energy model.Select one: a. 0.006 Btu/hr.ft.F b. 0.006 kBtu/ft2/yr c. 0.08 Btu/hr.ft2.F d. 0.008 kBtu/ft2/yr e. 0.006 Btu/hr.ft2.F f. 0.06 Btu/hr.ft.F
b. 0.006 kBtu/ft2/yr
Which of the six factors below are used in the Phius 2021 Criteria Calculator to determine a residential project's space conditioning limits?Select one or more: a. Ventilation Rate b. Bedroom Count c. Building Envelope Area d. Average R-Value of Enclosure e. Internal Heat Gain Schedule f. Thermal Bridge Density g. Location / Climate h. Electricity Price i. Floor Area (iCFA) j. Dwelling Unit Count
b. Bedroom Count c. Building Envelope Area g. Location / Climate i. Floor Area (iCFA) j. Dwelling Unit Count
Choose four: In a passive building enclosure assembly, the vapor control layer... a. Should be placed on the colder dryer side of the assembly b. Can concentrate water vapor in assemblies if improperly specified c. Should always be a Class I vapor retarder d. May be comprised of taped OSB e. May also serve as the water resistive barrier f. Manages migration of vapor into and through the assembly
b. Can concentrate water vapor in assemblies if improperly specified d. May be comprised of taped OSB e. May also serve as the water resistive barrier f. Manages migration of vapor into and through the assembly
A tinyhome that is designed to meet the Phius 2021 passive building criteria has a iCFA of 875 ft², peak heat loss through the envelope of 1525 BTU/hr, peak ventilation loss of 1850 BTU/hr, and peak solar gains of 900 BTU/hr.If peak internal gains are included in the calculation, per passive house load calculation protocol, what is the minimum BTU/hr the heating system must be capable of delivering to maintain an interior air temperature of 68°F at the peak design condition?Select one: a. 2475 BTU/hr b. 2690 BTU/hr c. 3600 BTU/hr d. 2029 BTU/hr
d. 2029 BTU/hr
Choose four: What is achieved through ventilation in passive buildings?Select one or more: a. Maintain the occupant well-being associated with the sense of a constant breeze of >19.7 ft/min b. Control temperature and humidity inside the building c. Provide the necessary fresh (supply) air d. Save energy through high recovery efficiencies e. Minimize odors, carbon dioxide, and airborne contaminants f. Maintain only minimum legal indoor air quality
b. Control temperature and humidity inside the building c. Provide the necessary fresh (supply) air d. Save energy through high recovery efficiencies e. Minimize odors, carbon dioxide, and airborne contaminants
What four factors are critical for ensuring moisture performance of a passive building window installation? Select one or more: a. Layering of rough opening flashing so it is behind the drainage plane of the wall assembly b. Exterior window taping c. Placement of window in the middle of the wall insulation layerd. Use of mounting flange e. Vapor permeance of window tape(s) in alignment with vapor control layer of the wall f. Sill pan placement and slope g. Proper flashing of the rough opening h. Filling of shim space with foam i. Over-insulation of window frame
b. Exterior window taping e. Vapor permeance of window tape(s) in alignment with vapor control layer of the wall f. Sill pan placement and slope g. Proper flashing of the rough opening
Which four of the following items limit transmission losses or gains in a Phius project?Select one or more: a. High-conductivity intersection and connection details b. High R-value opaque assemblies c. Thermally broken window frames d. Minimized U-factor of glazing e. Increased effective heat recovery efficiency of the ventilation unit f. Low ratio of enclosure surface area to interior volume
b. High R-value opaque assemblies d. Minimized U-factor of glazing f. Low ratio of enclosure surface area to interior volume
Three: If indoor air relative humidity levels are too high, the following risks are present:
b. Increase in dust mite population c. Increased potential for health issues d. Increase in dust accumulation e. Mold growth
What are the two most effective strategies for achieving the lowest frame-to-wall psi value (installation thermal bridge) of a window?Select one or more: a. Install the window on the inside of the wall assembly b. Install the window in the middle of the wall assembly c. Add insulation over the exterior of the frame d. Install the window on the outside of the wall assembly e. Increase the R-value of the window glazing
b. Install the window in the middle of the wall assembly c. Add insulation over the exterior of the frame
Consider all of the following materials to have an R-per-inch-value of 3. Given their embodied energy, which material has the lowest energy payback period? a. Polyurethane b. Mineral wool c. Polystyrene
b. Mineral wool
Choose three: Which of the following are primary passive building strategies for opaque enclosure design?Select one or more: a. Minimize energy use and operational costs by meeting the peak heating and annual cooling demand thresholds b. Minimize heat loss/gain, drafts, and moisture diffusion into assemblies with a continuous air barrier c. Minimize dewpoint risk by dehumidifying the indoor air d. Create steady interior surface temperatures with continuous insulation e. Avoid condensation, mold, and building deterioration risk with thermal bridge free construction f. Use only hygroscopic materials to achieve hygric buffering
b. Minimize heat loss/gain, drafts, and moisture diffusion into assemblies with a continuous air barrier d. Create steady interior surface temperatures with continuous insulation e. Avoid condensation, mold, and building deterioration risk with thermal bridge free construction
You need to calculate the indoor surface temperature for a particular glazing to determine whether it meets the recommended comfort criteria in your climate.You know the whole window U-value and the indoor and outdoor temperatures you want to use. What two additional pieces of information do you need to complete the calculation?Select one or more: a. The psi value of the spacer b. The U-factor of the glazing alone c. The R-value of the wall assembly the window will be installed into d. The interior surface film resistance e. The exterior surface film resistance f. The mean radiant temperature of all the other surfaces in the room
b. The U-factor of the glazing alone d. The interior surface film resistance
In order to achieve a balanced ventilation system, which three of the following strategies should be used?Select one or more: a. Use a setback thermostat to ensure the summer bypass or "economizer" function works properly on the ventilation unit b. Use adjustable diffusers with airflow balanced to within 20% or 5 cfm, whichever is greater, of the design value c. Use Z-ducts to allow for passive airflow of make-up air from outdoors d. Use recirculating air streams to boost either supply or extract air to achieve balance e. Work with the HVAC installer and/or PHIUS+ Rater to make sure there is not more than 10% difference between supply and extract airstream flow rates f. Make sure there is an override function at the range hood so the ventilation system is completely shut down when the range hood is on g. Specify transfer grills or door undercuts to achieve a pressure differential between room and circulation space of no greater than 1 pascal when room door is closed h. Make sure diffusers are accessible to enable the homeowner/occupant to adjust for their personal preferences
b. Use adjustable diffusers with airflow balanced to within 20% or 5 cfm, whichever is greater, of the design value e. Work with the HVAC installer and/or PHIUS+ Rater to make sure there is not more than 10% difference between supply and extract airstream flow rates g. Specify transfer grills or door undercuts to achieve a pressure differential between room and circulation space of no greater than 1 pascal when room door is closed
What is the term for a material's ability to prevent heat from flowing through it, equal to the difference between the temperatures of opposite faces of the material divided by the rate of heat flow?
c. Thermal Resistance
A window has the following attributes:Glazing U-factor = 0.13 BTU/hr.ft²°FFrame U-factor = 0.25 BTU/hr.ft²°FWindow Width = 4 ftWindow Height = 6 ftFrame thickness = 3 inches (for left, right, sill and head)ΨSpacer = 0.023 BTU/hr.ft°FΨInstall = 0.034 BTU/hr.ft°FCalculate the installed U-factor of the window (Uw-installed). Do NOT use rounding during the calculation. Round manually to the 3rd decimal place for the result.Select one: a. Uw installed = 0.259 BTU/hr.ft²°F b. Uw installed = 0.009 BTU/hr.ft²°F c. Uw installed = 0.199 BTU/hr.ft²°F d. Uw installed = 0.121 BTU/hr.ft²°F
c. Uw installed = 0.199 BTU/hr.ft²°F
_________ is not included in the total losses when calculating a whole building energy balance for a Phius project.Select one: a. Conductance through thermal bridges b. Heat losses through air leakage c. Waste heat from appliances and lighting d. Transmission through windows e. Transmission through opaque assemblies f. Heat losses through ventilation
c. Waste heat from appliances and lighting
The source energy factor for U.S. grid-electricity under Phius 2021 is ___Select one: a. 2.8 b. 1.96 c. 1.1 d. 1.8
d. 1.8
A home was designed with the following conditions:Slab on grade, 2 storiesExterior Boundaries of footprint (to exterior of insulation) 30' x 50'Height from bottom of sub-slab insulation to top of attic insulation 22'iCFA = 2700 sf3 bedroomsUnder Phius CORE 2021, the source energy limit per person for this house is 5202 kWh/person.yr. What is the specific source energy limit for this house, expressed in terms of kBTU per square foot of Interior Conditioned Floor Area per year?Select one: (SEE SHEET) a. 19.7 kBTU/sqft.yr b. 32.9 kBTU/sqft.yr c. 24.5 kBTU/sqft.yr d. 26.3 kBTU/sqft.yr
d. 26.3 kBTU/sqft.yr
An architect on a passive house project team in Portland, OR proposes R-4 glazing units (Assume the R-value of the glazing includes the surface films). Portland's ASHRAE 99% design temperature is 29°F.What will the interior surface temperature of the glazing be at that design temperature? Round as needed to two (2) places for your final result.Select one: a. 62.42 °F b. 59.93 °F c. 58.25 °F d. 60.79 °F
d. 60.79 °F
A wall assembly from interior to exterior is comprised of the following:Gypsum wallboard sealed at all joints2x6 24"oc framed wall filled with dense-pack fiberglass3/4" OSB taped at seams4" mineral wool insulation boardSpun bonded polyolefin membrane (housewrap)3/8" well-ventilated cavity with PT furring stripsCement fiberboard claddingWhich two functions does the OSB serve in this assembly? a. Class I Vapor Control b. Water Resistive Barrier c. Class III Vapor Control d. Air Control Layer e. Thermal Boundary f. Class II Vapor Control g. Vapor Barrier h. Drainage Plane
d. Air Control Layer f. Class II Vapor Control
Certain Phius performance criteria vary by climate location. What is the primary reason for this?Select one: a. Temperature b. Supply air heating c. Solar radiation d. Cost-effectiveness & optimized design
d. Cost-effectiveness & optimized design
Which of the following factors is not required to calculate the remaining annual heating demand?Select one: a. Net ventilation volume b. Heating degree hours c. Area of enclosure d. Delta-T between indoor design temperature and outdoor worst case temperature e. U-factors of opaque and transparent assemblies f. CFM50 enclosure leakage g. Total heat recovery efficiency h. Psi value and lengths of thermal bridges with Psi values greater than 0.006 BTU/hr.ft.F
d. Delta-T between indoor design temperature and outdoor worst case temperature
The following wall assembly will be used to construct a Phius building, interior to exterior:¾'' Gypsum board withlatex paint2x4 Std frame at 24''OC½'' CDX Plywood, glued and taped for airtightness14'' dense packed cellulose2x4 Std frame at 24''OCTyvek exterior housewrap taped and air sealed¾''vented air gap and rain screen¾'' stained beveled wood sidingWhat is the primary advantage of this wall assembly? a. The wall assembly provides healthy indoor air quality b. The wall assembly is airtight c. The wall assembly can breathe d. The wall assembly has drying potential in any direction
d. The wall assembly has drying potential in any direction
