TREAT FAQ: Inputs and Improvements
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Where do I enter my Duct Blaster results? How do I allocate the leakage between supply and return?
Duct Blaster results can be entered under the "Heatin /Cooling" menu. Click the "Edit Primary Distribution" button and see "Duct Test Leakage at 25Pa". Either allocate the duct leakage evenly to supply and return (300CFM @ 25Pa = 150CFM each to supply and return) or 2/ 3 of leakage to return and 1/ 3 to supply. Return to Top
If an existing building does not have air conditioning can it be added as an improvement?
Put AC in the base building, but set the thermostat setpoint very high and the pre-retrofit AC efficiency very high. This will minimize/ eliminate existing AC usage. Then put in whatever AC you want for an improvement, with proper temperature setpoints and AC efficiency. (you will probably need to do this as a package, with thermostat change as one improvement and AC efficiency as another.) Energy savings will be negative (increase in kwh use), but it should model this situation well, as a work-around.
Another way to do it is to enter proposed AC system for the base building with capacity equal to 1Btu hr (lowest allowed by TREAT). Enter the heating/cooling thermostat for the base building with realistic cooling setpoints. Existing building cooling usage will be limited by system capacity (close to 0). Then you may create cooling system improvement and enter actual AC capacity. This improvement with model cooling usage -no need to create a package. Return to Top
TREAT allows only one fan space making it necessary to combine all fans into one. Is correct representation of actual ventilation possible?
You may model complex ventilation system with Treat if you define each space that have unique mechanical ventilation rate/ schedule separately. For example, building corridors are ventilated 24 hr/ day. There are also exhaust fans in each bathroom. To model mechanical ventilation in the building you need to split the building into three spaces: space that represents the portion of the building with no mechanical ventilation (whole building minus bathrooms and corridors), all corridors with mechanical ventilation, and all bathrooms. Then you may enter two fans, one for corridors, and one for bathrooms. Note that each fan may serve more than one space. Combining spaces and fans allow very flexible input of mechanical ventilation. Remember that you have to accurately allocate floor area, walls and windows to each space. Return to Top
Can I add a new fuel type as an improvement?
Yes. For example, your building has electric heat and you want to change it to natural gas. To model that you need to enter electricity and natural gas on the Fuels/Rates screen. Then create a heat plant improvement and specify natural gas as new heating fuel. Return to Top
What is the Btu/ SqFt-HDD default target value?
Default target heating energy usage Btu/SqFt-HDD is a default target value that may be later adjusted for each analysis period on the Analysis Periods screen. The value is used to calculate the investment potential of the building, which is illustrated on the Heating Energy Scorecard and the Investment Potential reports. The target is different for different buildings, however you may use the following numbers as guideline:
- best new homes: 2Btu/SqFt-HDD
- ENERGY STAR® homes: 5Btu/SqFt-HDD
- low usage existing homes: 7Btu/SqFt-HDD
- medium usage existing homes: 11Btu/ SqFt-HDD
- high usage existing homes: 15Btu/ SqFt-HDD
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How do I model a Rim Joist Improvement?
Create an unheated basement with 7' block walls (or other appropriate material) set it adjacent to "ground". Then create a 1' high uninsulated wall by the appropriate width. Set the exposure adjacent to air and choose N, S, E, or West. We end up with 8 walls in the basement, 4 adjacent to ground, and 4 adjacent to air. The rim joists have been defined and now can be insulated. Be sure to add an air sealing improvement as well. Insulating the rim joists significantly affects the infiltration to the basement. Create an improvement that reduces the "Unheated space infiltration." Aggregate the Rim Joist Insulation and Rim Joist Air Sealing into a single package. Otherwise, TREAT will only calculate the change in R-value and savings are low. Return to Top
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