Mineral glass wool in a wooden frame on a inclined wall near the wooden ceiling in a private house.

WHEN to contact heat pump design consultant for home energy renovations

As a follow-up to our recent post, “Where to Start with your Heat Pump Installation Project,” we have found that many homeowners don’t realize the significant benefits of starting your next home improvement project with your HVAC system in mind. When we say home improvement, we don’t mean changing countertops as that will not impact your home energy systems unless you plan to install radiant heat in your countertops. No, we mean specifically any envelope improvements you plan to undertake. The building envelope is your home’s outer shell, including walls, windows, doors, attic/roof, foundation, and anything associated with these assemblies, including insulation and vapor barriers. These components relate to your home energy system because the envelope acts as a thermal barrier between the indoor and outdoor space. Every heating and cooling system is designed based on the specific conditions of your building envelope – or at least it should be. The exact conditions affecting HVAC design include the home’s location (including particular orientation), the insulating values of each of those assemblies, the air volume in the house, air tightness, etc. 

Building Envelope Impacts Heat Pump Selection

Changes to any of these assemblies associated with the building envelope will impact the HVAC systems. With fossil fuel-based heating systems, there is a certain degree of flexibility where such renovations will not negatively impact the equipment. For example, adding insulation to your attic will reduce heat loss, and the impact on a fossil fuel furnace would be a reduced running time in the depths of winter. In an extreme case, we could see furnaces being significantly oversized after such renovations, causing short cycling, which would cause comfort and reliability concerns. Many furnaces today are multi-stage or variable, which would help negate these impacts. 

Greener Homes Program Switching to Heat Pump In Ontario

However, suppose you plan to complete envelope renovations to help reduce energy demand, specifically to transition your fossil fuel HVAC systems to electrified systems (heat pumps). We commonly see this with the Greener Homes program and energy audits recommending envelope improvements. In that case, it is essential to consider this to help guide your renovation decisions. We also recommend you make any improvements first to reduce the building loads before transitioning to a heat pump. However, knowing that you plan to install a heat pump, homeowners should have a complete Heat Loss / Gain calculation done on their home first so you can get a complete picture. This process can optimize the heat pump selection to ensure the most cost-effective approach.

HVAC Design Ontario Heat Loss

By building the energy model to calculate heat loss, we can adjust the R-values of the different envelope components to match the improvements you plan to make and weigh the costs and the benefits to the impact on the HVAC system sizing and overall comfort and efficiency. We can then compare your current HVAC system operating costs to various heat pump options. 

So, as you consider adding insulation, or changing windows or doors, per the Energuide Audit, you should contact an HVAC design professional early in the process to help you get the most cost-effective solution possible.

Evolved Thermal Energy Heat Pump Installer Network Ontario

At Evolved Thermal Energy, we help people with this process every day. Contact us via our Qualify form to get started today!

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