Understanding the real impact of existing ductwork on a central heat pump installation
Installing a central heat pump is an excellent choice to enhance thermal comfort and reduce energy consumption in any building. However, one crucial question frequently comes up for homeowners in Montréal, Laval, Longueuil, on the North Shore and South Shore: is it possible to install a central heat pump without having to replace the entire air duct system? At AirGreen, we answer this question every week, as it’s at the heart of many technical and budgetary concerns. Let’s explore the key points together.
What you first need to know about your home’s ductwork
Before considering a new central heat pump, you need to understand the role of the ducts:
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They ensure even distribution of heated or cooled air throughout every room.
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They must be properly sized to match the capacity (BTU) of the heat pump.
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They must be airtight and well-insulated, especially in homes across Greater Montréal where extreme temperature swings are common.
Can you keep your existing ductwork? Yes, but under certain conditions
Yes, it’s often possible to install a central heat pump using existing ductwork, but it all depends on their condition and compatibility with the selected equipment. Here are the determining factors:
1. The physical condition of the ducts
At AirGreen, during every assessment visit, we inspect the condition of the ducts. If we notice corrosion, air leaks, separation, or mold, a partial replacement or refurbishment may be necessary.
2. The compatibility of dimensions
Old oil or natural gas furnaces often had oversized ductwork. A modern central heat pump, like the Bosch BOVA R-454B, requires a precise airflow. If the ducts are too large or too small, this can compromise efficiency, cause whistling noises, and shorten the system’s lifespan.
3. Static pressure
We use specialized instruments to measure the static pressure in the duct network. Too much or too little pressure hinders air circulation. This is a critical step in determining whether the installation can proceed without modification.
Case study: a successful installation using existing ductwork in Laval
A residential client in Laval, living in a 1980s bungalow, wanted to replace their old oil furnace with a 3-ton Goodman R-32 central heat pump. During our technical evaluation:
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The ducts were galvanized steel, well-maintained, and properly insulated.
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The layout and vent distribution were compliant.
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We only adjusted a few elbows to optimize airflow.
The result? A quick 2-day installation, optimal comfort from week one, and eligibility for the Hydro-Québec LogisVert rebate, totaling $5,000.
In what cases is duct replacement unavoidable?
There are situations where we recommend replacing the ductwork, including:
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Century-old homes with asbestos-lined or heavily corroded ducts.
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Duct systems originally designed for gravity or with long runs lacking flexible connections.
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Major air infiltration problems detected during our blower door test.
In these cases, a full upgrade ensures optimal performance and makes you eligible for government rebates.
AirGreen’s tips for maximizing your comfort
At AirGreen, we believe a high-performing HVAC system doesn’t depend solely on the installed unit, but on the intelligent integration of all its components, including ductwork. Here are our practical recommendations:
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Have your ducts inspected before purchasing your central heat pump.
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Request a compatibility report between your duct system and the proposed unit.
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Don’t hesitate to invest in a partial reconfiguration of your ducts if it improves airflow and reduces energy use.
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Always ask for an airflow calibration after installation to ensure quiet and efficient operation.
The AirGreen approach: expertise, precision, and transparency
Our technical teams travel every week across Montréal, Longueuil, Sainte-Julie, Repentigny, Laval, and Brossard to deliver custom central heat pump installations. Whether you choose a Fujitsu KZAH R-32, a Goodman R-32, or a Bosch IDS Premium, we make sure to:
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Perform a detailed thermal assessment.
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Verify the state of your ductwork and offer tailored solutions.
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Work efficiently, cleanly, and according to CSA-C22 standards.
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Help you apply for available rebates (LogisVert, RénoClimat, etc.).
Real-life examples of AirGreen installations with or without duct modifications
Installation without duct replacement – Montréal (Ahuntsic)
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Semi-detached home with ductwork in good condition.
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Installed a 2.5-ton Bosch central heat pump.
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No replacement required, except for adding one vent in the basement to balance airflow.
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Rebate received: $4,350 through LogisVert.
Installation with partial replacement – Longueuil (Saint-Hubert area)
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Home built in 1974 with uninsulated, outdated ducts.
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Replaced attic sections only.
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Installed a Fujitsu central heat pump with smart thermostat.
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Result: improved efficiency and reduced air loss.
In conclusion: make the right choice with an HVAC expert
Installing a central heat pump without replacing the ductwork is absolutely possible, as long as a thorough analysis of your existing duct system is carried out. At AirGreen, we leave nothing to chance: our goal is to provide a perfectly integrated system that maximizes your comfort, reduces your energy bills, and meets the highest standards.
Reach out to our experts for a free HVAC system evaluation in Montréal, Laval, Longueuil, the North Shore, and the South Shore. Let’s determine together whether your existing ducts can be reused and how we can optimize your comfort without unnecessary work.