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When Heat Pumps are not enough: Heat Pumps vs Ventilation Systems vs Air Purification

  • Writer: Geraldine C.
    Geraldine C.
  • Jun 17
  • 6 min read

Following our article last week about Improving Indoor Air Quality, this week, we answer the question "When heat pumps are not enough" - a deeper look into ventilation systems and air purification. While your heat pump significantly improves the air you breathe, it's essential to understand that it is not a complete air purification or a fresh air ventilation system. As their name suggests, a heat pump's primary purpose and focus is to warm or cool the air. While they recirculate and filter internal air, they are unable to fully purify the air as effectively as a dedicated air purifier can. Also, unless you have a ducted system with an outside air duct, they are also not able to introduce fresh air into your home, meaning that whatever pollutants and toxins are inside, you will end up recirculating them if they are too fine for the heat pump filters to trap. For truly comprehensive indoor air quality, particularly in modern, well-sealed homes, therefore, coupling your heat pump with a dedicated balanced fresh air ventilation system is the best solution.


Why Ventilation is Crucial

Balanced ventilation introduces fresh, filtered outdoor air into your home while expelling stale, contaminated indoor air. This addresses issues that heat pumps alone cannot, such as:

List of why ventilation system is crucial
  • Diluting Pollutants: Continuously replaces indoor air laden with VOCs, carbon dioxide (from breathing), and other airborne pollutants with fresh air. The best balanced ventilation systems [link to Ventus] have sensors that detect high PM2.5 and CO2 levels inside the home and automatically adjust their performance accordingly

  • Managing Humidity: While heat pumps dehumidify, a balanced pressure ventilation system can continuously extract excess moisture, further preventing condensation and mould, especially in moisture-prone areas like bathrooms and laundries

  • Removing Odours: Balanced ventilation helps to remove lingering cooking odours, pet smells, and other unpleasant indoor scents. Advanced systems like the Ventus even have ‘Boost’ functions that can deal with burnt toast and other sudden, strong smells

  • Preventing Stale Air Syndrome: Ensures a constant supply of fresh air, contributing to healthy oxygen levels, which increase alertness and comfort.


Types of Ventilation Systems for New Zealand Homes

  • Positive Pressure Ventilation (PPV): Draws fresh air from the roof cavity (or directly from outside via a filter) and gently pushes it downstairs into the living spaces, creating a slight positive pressure that forces stale air out through gaps and cracks through windows and doors. This is a common and cost-effective solution in many New Zealand homes, however, it is not suited to newer homes, which are more airtight and don’t allow air to escape as easily. Damp air trapped inside the house can then be forced into wall cavities, which is something to be avoided.

  • Balanced Pressure Ventilation (BPV) / Heat Recovery Ventilation (HRV): These systems feature two (or more) fans – one to bring in fresh air and one to extract stale air. The best ones incorporate a heat exchanger that transfers heat from the outgoing stale air to the incoming fresh air, recovering up to 90% of the heat that would otherwise be lost. This is the most energy-efficient and comprehensive ventilation solution, ideal for airtight homes or those looking for superior air quality without significant heat loss and excessive heating bills.

  • Extractor Fans: These are bare basic, essential fans located in bathrooms and kitchens to remove moisture and odours at the source; however only deal with one room and cannot see dampness accumulating in other areas of the house. Because they are often very noisy, they are often run on timers or off light switches and turn off once the switch is turned off.


At OneAir, we don't just stop at heat pump installation. We offer comprehensive advice and expert ventilation system installation services tailored to your specific home and needs. Integrating a suitable ventilation system with your heat pump creates a holistic approach to indoor climate control, ensuring your home is warm, dry, and filled with clean, healthy air year-round. Don't underestimate the profound impact a well-designed ventilation system can have on your family's health and comfort this winter.


Clearing the Air: Understanding PM2.5 and the Power of Air Purification

In our quest for healthier living environments, "air purification" has become a buzzword. But what exactly are we purifying the air from, and why is it so important? A major culprit in indoor and outdoor air pollution is PM2.5, and understanding it is key to appreciating the role of air purifiers.


What is PM2.5?

PM2.5 refers to fine particulate matter with a diameter of 2.5 micrometers or less. To put that into perspective, it's about 30 times smaller than the average human hair. Due to their minuscule size, these particles can easily be inhaled deep into our lungs and even enter the bloodstream, posing significant health risks. This is why PM2.5 is often considered one of the most dangerous air pollutants.


Common Sources of PM2.5

PM2.5 can originate from a variety of sources, both natural and human-made:

Combustion Processes: This is a major contributor. Sources include:

  • Vehicle emissions: Exhaust from cars, trucks, and buses.

  • Industrial activities: Emissions from factories and power plants.

  • Burning of solid fuels: Wood-burning stoves, fireplaces, agricultural burning, and even candles and incense.

  • Wildfires: Natural occurrences that release vast amounts of smoke and particulate matter.

  • Cooking: Frying, grilling, and even toasting can release PM2.5 indoors.

Dust: Construction dust, road dust, and even dust from everyday activities like cleaning can contribute.

Chemical Reactions: Certain gases in the atmosphere can react to form solid PM2.5 particles.


The Highway Hazard: A PM2.5 Hotspot

If you reside near a busy highway, PM2.5 becomes a particularly heightened concern. Vehicle emissions are a substantial source of these fine particles. Beyond exhaust fumes, brake linings, and tire wear also release a considerable amount of PM2.5 into the air. The constant movement of vehicles stirs up road dust, further exacerbating the problem. Living close to such areas means you are regularly exposed to elevated concentrations of these harmful particulates.


How Air Purifiers Help

This is where air purifiers come into play. High-quality air purifiers, especially those equipped with HEPA (High-Efficiency Particulate Air) filters, are designed to capture microscopic particles like PM2.5. These filters work by trapping particles as air passes through a dense mesh of fibers, effectively removing them from your indoor environment. By actively filtering the air, an air purifier can significantly reduce your exposure to PM2.5, contributing to a healthier home, especially if you live in an area with high outdoor pollution levels.


Why an Air Purifier is a Winter Essential

Air purifiers are often seen as unnecessary gadgets, but they can be a valuable addition to your home, especially during winter when natural ventilation is limited. A good air purifier can significantly improve your indoor air quality.

List of why air purification is essential

Here are six compelling reasons to consider purchasing an air purifier before the colder months set in:

  1. Combats Wood Smoke: If your home is affected by smoke from fireplaces, an air purifier can effectively filter out these pollutants. Look for models with high smoke removal scores if this is a primary concern.

  2. Reduces Viruses and Bacteria: Air purifiers equipped with a HEPA (high-efficiency particulate arresting) filter can capture airborne viruses and bacteria as small as 0.3 microns, helping to reduce the spread of winter illnesses.

  3. Manages Dust: For those with allergies or simply looking to reduce dust, an air purifier can significantly reduce airborne dust particles. Some models are much more effective at this than others.

  4. Filters Pet Dander and Hair: As pets spend more time indoors during winter, their dander and hair can become more prevalent. A HEPA filter in an air purifier will trap these allergens, providing relief for allergy and asthma sufferers.

  5. Removes Mould Spores: While an air purifier can't eliminate existing mould growth, it can remove airborne mould spores, preventing their spread. For comprehensive mould control, pair it with a dehumidifier to address the root cause of moisture.

  6. Traps Pollen (as Winter Transitions to Spring): As winter gives way to spring, an air purifier can continue to be beneficial by capturing airborne pollen, potentially offering relief for those who suffer from hay fever.


Important Considerations: Beyond the Initial Price

When choosing an air purifier, remember to factor in the ongoing costs, particularly the price and replacement frequency of filters. According to Bryan Wall, an air purifier expert at Consumer NZ, filter costs can vary significantly and impact the overall long-term expense of owning the device. It's wise to compare these costs across different models before making a purchase.


Ready for truly clean, fresh, and healthy air? Contact OneAir today at 0800 663 247 for a FREE consultation on integrating the perfect ventilation and purification solutions with your heat pump!


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