Base Capacity on the Home, Not Floor Area Alone

Collect home records

Gather plans, year and renovation records, insulation or window work, conditioned area and known air-sealing results without inventing missing values.

Map room comfort

Record room-by-room hot, cold, noise or airflow concerns by season and time rather than averaging them away.

Describe existing use

Collect equipment models, service records, fuel or electricity history and thermostat practices as context—not a shortcut calculation.

Document distribution

Map ducts, registers, returns, doors, stairways and possible indoor-unit zones plus known access constraints.

Require a load method

Ask how design outdoor conditions, envelope, ventilation, infiltration, internal gains and room loads are handled.

Agree on assessment output and fee

Before booking, confirm the business responsible, the visit type and any fee. A preliminary installation estimate, repair diagnostic and detailed system design can have different scope and charges; do not assume a free quote includes all three. Ask which written outputs are included: load method and design conditions, room or zone results, distribution review, equipment and backup recommendation, electrical-capacity review, unresolved checks and installation price before assumed incentives. Confirm what is measured, assumed or separately priced. Sending a request does not establish an assessment offer, fee or booking.

Build a room-by-room comfort record

For each room, note use, occupancy, exposure, window context, existing emitter or register, seasonal complaint and door position. Add envelope changes separately so the assessment can distinguish current conditions from planned improvements.

• Record hot and cold periods
• Include basement and additions
• Avoid choosing capacity from floor area

Reconcile design inputs

Ask the proposal to state outdoor and indoor design conditions, envelope assumptions, ventilation or infiltration treatment, internal loads and calculation method. Resolve mismatches between site observations, audit data and default assumptions before equipment selection.

• Keep the calculation report
• Flag assumed construction values
• Recalculate after envelope changes

Connect capacity to distribution

A calculated building load must still be matched to ducts, heads, airflow, zoning and room delivery. Require the assessment to explain design-condition output, part-load operation, defrost, backup and unresolved distribution work.

• Map every served room
• Identify airflow constraints
• State backup design role

Complete the house-to-selection brief

Combine room comfort observations, envelope and renovation facts, design-condition assumptions, load calculation, duct or head distribution evidence, ventilation context, electrical information and backup goals. Identify values that were measured, documented or assumed and attach the qualified reviewer’s method. BC Hydro’s current rebate page says its whole-home route requires a heat-load calculation using CSA F280-12 verified software at the home’s design temperature; preserve the signed summary and the inputs used rather than copying only the final capacity. Record each exact indoor and outdoor model pairing, low-temperature output, supplementary-heat assumption and the rooms served. Compare the calculated load with manufacturer capacity at the relevant Vernon winter conditions, not nominal tonnage or mild-weather output. Note planned insulation, windows, air sealing, additions or suite work and state whether each change is already complete or remains an assumption. Connect the selected equipment pairing to ducts, heads, airflow, door position and room delivery, then identify the unresolved measurements and party responsible for them. BC Hydro’s retrofit best-practices guide also calls for electrical-capacity assessment that includes the heat pump and supplementary heat; attach that result without opening electrical equipment. Version the brief when equipment, envelope scope, distribution or backup strategy changes. The final issue should name the calculation author, software or method, design conditions, data date, accepted equipment and triggers for recalculation. The brief helps every proposal use the same house evidence without presenting floor area, an online estimate, historical bills, nominal equipment size, a rebate list or a cold-climate label as proof that capacity and comfort will be suitable.

• Map every served room
• Mark assumed envelope values
• Reference calculation revision
• Attach performance tables
• Name reassessment triggers