I've done mechanical rough-ins on new construction throughout the Interlake since 2011. The builds that have given homeowners the most satisfaction over the years are the ones where the HVAC was planned properly from the design stage — the system was sized correctly, ductwork was laid out with airflow in mind, HRV ventilation was integrated, and cooling was planned rather than retrofitted. The ones that cause problems are almost always the ones where mechanical was treated as an afterthought.
This guide covers every HVAC decision you'll face in a Manitoba new build — when each decision needs to be made, what the options are, and what we recommend for different build situations.
When to Engage Your HVAC Contractor
The answer is earlier than most homeowners expect: during the design phase, before construction begins. Here's why:
- Radiant in-floor heating requires a decision before the foundation is poured — PEX tubing is embedded in the concrete slab. There is no opportunity to add it later without major disruption.
- Duct routing affects framing — main trunk runs, chase locations, and return-air pathways need to be coordinated with the framing plan. A mechanical contractor reviewing the plans before framing starts prevents conflicts later.
- Equipment room sizing — furnace, air handler, HRV, water heater, and any filtration equipment all need space. Planning the mechanical room location and size during design avoids cramped installations.
- Electrical panel capacity — a dual-fuel heat pump, electric water heater, EV charger, and other modern loads require adequate panel capacity. Planning electrical with HVAC in mind prevents expensive panel upgrades later.
Heating System Decision
The primary heating system choice shapes everything else. The main options for Manitoba new builds:
High-Efficiency Gas Furnace + Central AC
The most common and least expensive option. 96–98% AFUE furnace with central air conditioning using shared ductwork. Proven reliability, widely serviceable throughout rural Manitoba, lower upfront cost. HRV integrates easily into forced-air ductwork. The right choice for cost-conscious builds, rural properties on natural gas, and projects where simplicity and service accessibility are priorities.
Dual-Fuel Heat Pump System
A cold-climate heat pump as primary with gas furnace backup. Lower long-term operating costs, lower carbon footprint, built-in cooling. Higher upfront cost than furnace-only. Well-suited to new builds where the homeowner plans to stay long-term and wants to take advantage of available rebates. For details on how these systems work, see our post on how a dual-fuel heat pump system works.
In-Floor Radiant Heating
The premium comfort option — warm floors, even heat, silent operation. Requires a separate cooling system (ductless mini-splits). Higher upfront cost. Decision must be made before foundation pour. Excellent for slab-on-grade construction. Full analysis in our post: Is In-Floor Heating Worth It in New Construction?
Boiler with Terminal Units
Superior zoning, good heat quality, but no built-in cooling and fewer service technicians in rural Manitoba. Analysis in our post: Boiler vs. Forced Air for a New Home Build in Manitoba.
For a full comparison of all heating system options, see our guide to choosing a heating system for a new build in Manitoba.
Ductwork Design
Poorly designed ductwork is one of the most common sources of comfort complaints in new homes — rooms that don't heat or cool adequately, pressure imbalances, noisy airflow. Good duct design requires:
Proper Sizing (Manual D Calculation)
Duct sizing should follow ACCA Manual D principles — each supply register receives adequate airflow for the room's heat load. Oversized main trunks with undersized branches, or undersized returns relative to supply, are common problems from undisciplined installations.
Adequate Return Air
Return air is the most commonly underdesigned element in residential ductwork. Every room needs a pathway for air to return to the air handler — either a dedicated return duct or adequately sized door undercuts. Closed doors with no return path create pressure imbalances that reduce system efficiency and create rooms that don't condition properly.
Duct Location
Ideally, supply ducts run within the conditioned envelope — inside insulated walls or through conditioned basement/crawlspace space. Ducts in unconditioned attic space lose significant heating and cooling energy even when insulated. Manitoba's extreme temperature differential between attic and living space makes attic ductwork a particularly significant energy penalty.
Ventilation: The HRV Requirement
Manitoba's National Building Code requires mechanical ventilation in new construction. Modern tight building envelopes (required for energy efficiency) don't allow enough air infiltration to meet code ventilation rates — a Heat Recovery Ventilator (HRV) is the standard solution.
An HRV brings fresh outdoor air in while exhausting stale indoor air. The heat exchanger core transfers up to 80–85% of the heat from exhaust air to incoming fresh air, so you're not losing all the heat energy you've paid for. In Manitoba's cold climate, this recovery efficiency is critical — a house without an HRV running continuously in winter develops poor air quality, excessive humidity from cooking and bathing with no exchange, and potentially elevated CO2 levels from occupancy.
HRV distribution options:
- Integrated into forced-air system (most common): The HRV connects to the furnace ductwork, using the furnace blower to distribute fresh air. Simple and cost-effective.
- Dedicated HRV ductwork: The HRV runs its own small duct system independent of the heating system. More expensive but provides ventilation regardless of heating/cooling operation, and allows more precise zone control.
The National Research Council's National Building Code sets the ventilation requirements for new construction that HRV systems satisfy. CMHC's guidance on indoor air quality covers ventilation requirements in new residential construction.
Cooling Planning
Manitoba summers have become reliably warm enough that planning for cooling in new construction is standard — not optional. Key decisions:
- Central AC: If you have forced-air ductwork, central AC uses the existing distribution infrastructure at relatively low added cost. This should be planned from the outset — adding AC to existing ductwork is straightforward; retrofitting ductwork later is disruptive and expensive.
- Ductless mini-splits: For radiant-heated homes or as supplements for areas the central AC doesn't reach well. Each unit conditions one zone independently.
- Heat pump (cooling mode): A heat pump provides cooling as a built-in function — the same equipment serves both heating and cooling. No separate AC unit is needed.
Water Heating Integration
New construction is the right time to consider how domestic hot water integrates with the heating system:
- Dedicated high-efficiency water heater (power vent or direct vent gas, or heat pump water heater): Most common and simplest approach.
- Combi-boiler or indirect tank: If installing a boiler system, a combi-boiler or indirect hot water tank eliminates a second appliance while providing both space heating and domestic hot water from one system.
- Heat pump water heater: Standalone heat pump water heater (hybrid electric water heater) provides 2–3x the efficiency of conventional electric at modest upfront premium. Works well in basements or mechanical rooms with sufficient air volume.
New Construction Mechanical Coordination
Our approach to new construction: we engage during the design phase, review the building plans for mechanical room sizing and duct routing, coordinate with the general contractor and framing crew to ensure mechanical pathways are in place before drywall, and complete the installation in phases — rough-in during framing, trim-out and commissioning near completion.
Our new construction plumbing and mechanical service covers complete HVAC and plumbing for new builds throughout the Interlake. Contact us at the design stage — not after framing is complete.
Planning a New Build in Manitoba?
Engage us at the design stage — before framing, before foundation pour if you're considering radiant. We get it right from the ground up. Serving Stonewall, Winnipeg, and the Interlake.
Start the Conversation EarlyFrequently Asked Questions
When should I hire a mechanical contractor for a new build?
During the design phase — before construction begins. If you're considering in-floor radiant, the decision must be made before the foundation is poured. For any system, having the mechanical contractor review plans before framing prevents conflicts between duct routing and structural members. Early engagement also allows proper mechanical room sizing and electrical panel capacity planning. Don't wait until framing is complete to hire your HVAC contractor.
Is an HRV required in a new home in Manitoba?
Yes. Manitoba's building code (based on the National Building Code of Canada) requires mechanical ventilation in new residential construction. Modern tight building envelopes don't allow sufficient natural air infiltration to meet code ventilation rates. An HRV (Heat Recovery Ventilator) is the standard solution — it brings in fresh air while recovering heat energy from exhaust air, satisfying both the ventilation requirement and the energy efficiency goal of not wasting heated air.
Should I plan for central AC in my Manitoba new build?
Yes, if you're installing a forced-air heating system. Manitoba summers have become reliably warm enough that air conditioning is now considered standard in new construction rather than optional. Planning for AC from the start costs very little incremental to the forced-air system — essentially the cost of the AC unit and electrical circuit. Retrofitting AC to existing ductwork later is straightforward. If you install a heat pump system, cooling is built in.
How does fuel availability affect HVAC choices for rural Manitoba builds?
Significantly. Rural Manitoba properties without natural gas service rely on propane, electricity, or both. At current propane prices relative to Manitoba Hydro electricity rates, heat pump heating is often more economical than propane — changing the economic case for heat pumps compared to natural-gas-available properties. Propane backup in a dual-fuel configuration is an option, but heat pump + electric backup can work for well-insulated new builds where peak heating loads are reduced by the building envelope. We calculate the operating cost comparison for each property's specific situation.