An air cleaner (also called an air purifier or air filtration system) is a device designed to remove contaminants from indoor air. There are two main categories:

• Portable/standalone air cleaners – designed for a single room or area.
• Whole-home air cleaners – installed directly into your HVAC ductwork to treat air as it circulates throughout your entire home.

For Ontario homeowners dealing with seasonal allergens, cold-weather indoor living, and the occasional wildfire smoke that drifts into the GTA, a whole-home air cleaner is often the most effective long-term investment.

Most air cleaners follow the same basic process: draw air in, pass it through one or more filtration or purification stages, and push clean air back out. The real differences lie in the technologies used in each stage.

1. Mechanical Filtration (HEPA & Media Filters)

The most widely used method is mechanical filtration, where air is forced through a dense filter medium that physically traps particles. High-Efficiency Particulate Air (HEPA) filters are the gold standard, capturing 99.97% of particles as small as 0.3 microns — that includes most allergens, dust mites, mould spores, and airborne bacteria.

Whole-home media filters work on the same principle but are sized to fit into your HVAC air handler or ductwork, cleaning all the air that passes through your heating and cooling system. These filters need to be replaced periodically — typically every 6 to 12 months depending on usage and air quality conditions in your area.

2. Electrostatic Precipitation

Electronic air cleaners use an electrical charge to capture particles. As air passes through the unit, particles become electrically charged and are then attracted to oppositely charged collection plates — similar to how a magnet attracts metal. This technology is highly effective at trapping very fine particles, including smoke and microscopic allergens.

Electronic air cleaners installed in your HVAC system are reusable — the collection plates are washed rather than replaced, which makes them cost-effective over time. Lennox, one of the premium brands we carry at Constant Home Comfort, produces electronic air cleaners that integrate seamlessly with their furnace and air handler systems.

3. UV-C Light (Ultraviolet Germicidal Irradiation)

UV air purifiers use ultraviolet light to destroy the DNA and RNA of microorganisms — bacteria, viruses, and mould spores — rendering them unable to reproduce or cause harm. UV-C systems are typically used in combination with a mechanical filter and are especially popular in homes where someone has a respiratory condition or compromised immune system.

Note: UV light alone doesn't remove particles from the air. It works best as a complement to a HEPA or media filter system.

4. Activated Carbon Filtration

Activated carbon filters are specifically designed to absorb gases, odours, and volatile organic compounds (VOCs) — substances that standard particulate filters can't capture. These include cooking odours, pet smells, cigarette smoke residue, cleaning product fumes, and off-gassing from new furniture or flooring.

Activated carbon layers are often found as a pre-filter or secondary filter stage in multi-stage air purification systems.

5. Photocatalytic Oxidation (PCO)

PCO technology combines UV light with a titanium dioxide catalyst to produce hydroxyl radicals that break down organic compounds at a molecular level. It's effective against bacteria, viruses, mould, and certain chemical pollutants. Advanced PCO systems are increasingly common in high-efficiency HVAC-integrated air cleaners.

Standalone units are easy to set up and can be moved from room to room, but they only treat the air in one space at a time. For a small apartment or a single problem room — like a basement with humidity issues — they can be a practical solution.

Whole-home air cleaners, installed into your existing HVAC ductwork, treat every cubic foot of air that moves through your furnace or air conditioner. This means consistent air quality across every room, without multiple devices running. For most Ontario homeowners — especially those with families, pets, or allergy sufferers — whole-home integration is the smarter, more efficient choice.

Depending on the technology used, a quality air cleaner can reduce or eliminate:

• Dust and dust mites
• Pet dander and hair
• Seasonal pollen (a major concern in Ontario's spring and fall)
• Mould spores
• Smoke particles (including wildfire smoke)
• Bacteria and viruses
• VOCs and chemical off-gassing
• Odours from cooking, pets, cleaning products, and more

Not sure if your home would benefit from an air cleaner? Here are some common signs:

• You or a family member suffers from seasonal allergies, asthma, or chronic respiratory issues.
• Visible dust buildup returns quickly after cleaning.
• Your home has persistent odours that don't seem to go away.
• You have pets or live in a high-traffic household.
• You live near a busy road, industrial area, or have experienced wildfire smoke in the area.
• Your home has been recently renovated or has new furniture/flooring that may off-gas VOCs.

A whole-home air cleaner is typically installed in the return air duct of your furnace or air handler — the section that draws air back from your living spaces into the HVAC system. Every time your heating or cooling system runs, household air passes through the cleaner before being conditioned and redistributed.

This means your air cleaner works in sync with your existing system — no separate operation required. Many modern systems also include smart controls that let you monitor filter status and air quality from your thermostat or a smartphone app.

Our licensed HVAC technicians at Constant Home Comfort will assess your current system, recommend the right air cleaner model, and handle the full installation. We serve Toronto, the GTA, Hamilton, Ottawa, Barrie, London, Waterloo, and surrounding communities across Ontario.

Like any HVAC component, air cleaners require regular maintenance to perform at their best. General guidelines include:

• Media filters: Replace every 6–12 months depending on air quality and household activity.
• Electronic/electrostatic cleaners: Clean collection plates every 1–3 months by washing with water.
• UV bulbs: Replace annually, as UV output degrades over time even if the bulb appears lit.
• Activated carbon filters: Replace every 3–6 months, as carbon becomes saturated over time.

We offer annual maintenance plans to keep your entire HVAC system — including your air cleaner — running efficiently all year long.

Does an air cleaner help with allergies?

Yes. A HEPA-rated air cleaner significantly reduces airborne allergens such as pollen, dust mites, and pet dander — the most common triggers for allergy and asthma symptoms. Many customers report noticeably improved comfort during Ontario's peak allergy seasons in spring and fall.

How is an air cleaner different from a regular furnace filter?

A standard 1-inch furnace filter is designed primarily to protect your HVAC equipment from large debris. An air cleaner is engineered to actually improve indoor air quality, capturing microscopic particles and pathogens that a basic filter would pass right through.

Can I install an air cleaner myself?

Standalone units can be placed in a room without professional help. However, whole-home air cleaners that integrate with your HVAC ductwork should be installed by a licensed technician to ensure proper airflow, sizing, and performance. Improper installation can restrict airflow and reduce both air quality and system efficiency.

How much does a whole-home air cleaner cost in Ontario?

Pricing varies based on the technology and brand selected. Constant Home Comfort offers competitive pricing with full installation included, and our team is transparent about costs upfront. Contact us for a no-obligation quote tailored to your home and budget.

Will an air cleaner remove COVID-19 or other viruses?

HEPA filtration systems rated at 99.97% can capture particles in the size range of many viruses when they are carried on larger airborne droplets. Systems that combine HEPA filtration with UV-C germicidal technology offer the highest level of pathogen protection. While no system can guarantee 100% protection, a properly installed whole-home air cleaner meaningfully reduces the concentration of airborne pathogens.

Your family deserves clean, healthy air — not just in theory, but in every room of your home, every single day. Constant Home Comfort is Ontario's trusted HVAC and indoor air quality specialist, serving Toronto, GTA, Hamilton, Ottawa, Barrie, Waterloo, London, and beyond.

Our team of licensed technicians will assess your home, recommend the right air cleaner for your needs and budget, and install it with zero guesswork. We carry top brands including Lennox and other leading manufacturers, with full installation, maintenance plans, and protection packages available.

Call us at 1 (888) 675-5907 or book your in-home appointment online.

Clean air starts with one call.