Worked project
See the inputs. Check the result.
Follow two small offices through a Loads calculation, then inspect the actual report format. The plan, reference inputs and report are free to download—no account required.
Watch first. Explore the details below.
From floor plan to reviewed loads.
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Read the video transcript
Start with a small task
Start with one small task in MEPFlow: reviewing the heating and cooling loads for two offices. This worked example takes you from a scaled plan to the input schedule, room results and calculation report. Everything you see here is available to inspect before you create an account.
Establish the geometry
First, establish the geometry. The plan contains two offices, each five by eight metres, with a shared interior wall. One window faces west and the other east. In Loads, upload the PDF, calibrate the ten metre width, then trace the rooms and place the windows.
Set the assumptions
Next, enter the design assumptions: construction, glazing, indoor temperatures, people, equipment and outdoor air. This example uses deliberately stated teaching conditions. The temperatures and ventilation rates are not design recommendations. The reference file lists the inputs so you can review what drives the result.
Review the results
Now review the calculation. Heating is four point zero five kilowatts. Coincident cooling is four point four zero. The sum of the room cooling peaks is four point five zero, because east and west rooms peak at different times. Check assumptions before selecting equipment.
Inspect the report
Finally, inspect the calculation report. It shows the method, assumptions and room schedule. Its pass status means input consistency, not design approval.
Step 01 / Establish the geometry
Same area. Different solar exposure.
Each room is 40 m². Their shared wall is an interior partition; one window faces west and the other east. This makes it useful to compare room peaks with the simultaneous building result.
Recreate the example in Loads
- 1.Download the teaching plan and upload it as a PDF background.
- 2.Calibrate the full 10 m width. Trace two adjacent 5 × 8 m spaces.
- 3.Confirm the shared wall is interior. Place the two exterior windows and set their sizes.
Step 02 / Set the design assumptions
Know what the numbers represent.
These are teaching inputs, including assumed weather and outdoor-air rates. For a real project, select applicable design conditions, ventilation requirements, infiltration and construction data. The example is located at Winnipeg coordinates for solar geometry; its temperatures are not a Winnipeg design recommendation.
- Geometry
- Two 5 × 8 m rooms; 3 m high; one shared partition
- Envelope
- Wall and roof RSI 5 m²·K/W (U 0.20 W/m²·K); floor above conditioned space
- Windows
- One 2 × 1.5 m window per room; U 1.8 W/m²·K; SHGC 0.35; east/west; no overhang
- Indoor conditions
- Heating 21°C; cooling 24°C at 50% RH
- Teaching weather
- Custom July 21 day: 30°C dry bulb, 20°C wet bulb, 10°C daily range; winter −20°C
- People and gains
- 4 people per room; 75 W sensible + 55 W latent per person; lighting 8 W/m²; equipment 10 W/m²
- Outdoor air
- Engineer-entered 2.5 L/s per person + 0.3 L/s per m² = 22 L/s per room
- Other assumptions
- Office schedules; zero infiltration for this example; no heat recovery or safety margin
Advanced inputs and reproducibility
North rotation is 0°; latitude 49.92°, longitude −97.23°, elevation 239 m and UTC offset −6. Custom clear-sky optical depths are 0.35 beam and 2.3 diffuse. Cooling/heating supply-air assumptions are 13°C/35°C. The complete reference file includes construction classes, radiant fractions, shade multipliers and schedules.
Download reference inputs (JSON)The JSON documents the calculation inputs. It is not an app project-import file.
Step 03 / Calculate and review
Room peaks and a coincident total.
MEPFlow’s existing Loads engine produced these results for the published inputs. The room cooling peaks occur at different times. The coincident result sums both rooms at the same hour.
Block heating
4.05kW
Coincident cooling
4.40kW
Sum of room cooling peaks
4.50kW
| Room | Heating | Cooling total | Cooling peak | Cooling airflow |
|---|---|---|---|---|
| West office | 2.03 kW | 2.43 kW | 16:00 LST | 166 L/s |
| East office | 2.03 kW | 2.07 kW | 11:00 LST | 138 L/s |
Check one component by hand
For each room: 18 m of exposed wall × 3 m high − 3 m² of glazing gives 51 m² of opaque wall. At RSI 5 and a 41°C temperature difference:
51 ÷ 5 × 41 = 418.2 W
The engine returns 418.2 W for that heating component. Independent checks also match window conduction (221.4 W), roof conduction (328 W) and the entered 22 L/s outdoor air. These checks do not validate every cooling calculation.
Review before selecting equipment
- Cooling airflow uses sensible load and the 13°C supply-air assumption; it is not the 22 L/s outdoor-air rate.
- Heating does not credit solar or internal gains. Ventilation adds to the envelope heat loss.
- No infiltration, heat recovery, fan heat, duct gain or equipment performance is included in this teaching case.
Step 04 / Inspect the deliverable
Open the actual calculation report.
Two-room Loads report
A one-page PDF showing the method, design assumptions, outdoor-air authority, load summary, room schedule and consistency-review status. It uses the same report generator as the app’s Calculation Report → Export PDF command.
Generated on 10 September 2026 from the unchanged app calculation and report code, using an offline example. “PASS” means input-consistency checks passed, not certification or design approval. The sample does not test a live account’s download flow.
Try a small project you can check.
Create an account, open Peak Loads and follow the example with your own inputs. Your website calculator results and these sample files do not transfer automatically into the app.
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