Efficiency and running costs in Whitby
What a heating and cooling system costs to run is decided by three things: how much energy the house needs, how efficiently the equipment converts fuel or electricity into that energy, and how much of the output actually arrives in the rooms. Most conversations about efficiency only cover the middle one. Metropolitan Heating and Air Conditioning has worked on all three across the GTA since 1979, Whitby included.
Call (416) 283-5698, Monday to Friday 8:00 AM to 4:00 PM.
What a bill is actually made of
Consumption is the load multiplied by the runtime needed to meet it, divided by the efficiency of the equipment doing the work. The load is a property of the house — its insulation, air tightness, window area, and the temperature difference between inside and outside on a given day. The equipment rating is a property of the box. The distribution losses sit in between, and they belong to the ductwork.
This explains a common outcome: a house gets new high-efficiency equipment and the bill moves less than expected. Nothing has failed. The equipment improved one term in the calculation while the other two stayed where they were.
Efficiency ratings describe the equipment, not your house
AFUE is the seasonal efficiency of a furnace — the proportion of fuel energy that ends up as usable heat rather than going out the flue. SEER and its successor SEER2 describe seasonal cooling efficiency; HSPF and HSPF2 do the same for heat pumps in heating mode.
All of these are measured under standardised laboratory conditions. They are useful for comparing two pieces of equipment against each other, which is what they were designed for. They are not predictions of what a particular house will consume, because the test conditions are not your house, your ductwork or your winter. Treat a rating as a comparison tool, not a forecast.
The things that move consumption most
In rough order of how much they tend to matter:
- The load itself. Insulation and air sealing reduce how much energy the house needs in the first place. Nothing the equipment does can beat not needing the energy.
- Duct losses. Air escaping from supply ducts, or heated and cooled air delivered to unconditioned space, is energy paid for and not received. Ducts running through an unheated basement or attic lose more.
- Airflow. Equipment is rated to hit its efficiency numbers at a design airflow. Restricted ducts or an over-dense filter raise static pressure, lower airflow, and pull real performance below the rating on the label.
- Equipment sizing. Oversized equipment short cycles, and start-up is the least efficient part of any cycle. It also removes less moisture in summer, which affects comfort at a given temperature.
- Control strategy. Setback schedules, staging and how the thermostat is configured decide how much of the day the equipment runs and at what output.
- Maintenance condition. Dirty coils, drifting refrigerant charge, fouled burners and a clogged filter all degrade efficiency gradually, with no obvious symptom until something fails.
Where efficiency claims come apart in practice
A furnace rated at 96% AFUE moving air through ducts that leak into a basement is not delivering 96% of that fuel to your rooms. A condenser with a high SEER2 rating paired with an old indoor coil is not a high-SEER2 system, because the rating applies to the matched pair.
The same logic applies to staged and variable-capacity equipment. It earns its rating by running longer at lower output rather than cycling hard, which means it needs ductwork that can carry that airflow and controls configured to let it modulate. Install it on restricted ducts with a thermostat that only knows on and off, and you have paid for capability the installation prevents it from using.
This is why commissioning measurements matter — airflow, static pressure, charge, temperature rise. They are the difference between the rating on the box and the performance in the house, and without them nobody knows which one you have.
What we look at
When running costs are the complaint, we measure before recommending: static pressure and airflow, temperature rise or split across the coil, refrigerant charge, gas pressure, filter and coil condition, thermostat configuration, and the duct layout. That distinguishes equipment that is underperforming from a house that is asking for more than the equipment was sized to give.
Often the outcome is maintenance and a duct or airflow correction rather than new equipment. Where replacement is the right answer, we will tell you what the rating assumes and what your installation would need to meet those assumptions, rather than quoting a number and leaving it there. We will not tell you what you will save, because that depends on your house, your usage and energy prices — none of which we can predict. Financing is available through Vista.
Call (416) 283-5698, Monday to Friday 8:00 AM to 4:00 PM, or send us the details. Licensed and insured, all makes and models. Whitby is one of the places we cover — see the full service area.