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How can I determine the right size of an HVAC system for my home in Vaughan, Ontario

AlpHeating | Posted in General Questions on

I understand that factors like the square footage, insulation, and number of windows play a role, but I want to ensure that I’m not undersizing or oversizing the system. What specific calculations or methods do HVAC professionals use to properly size a system to maintain energy efficiency and comfort? Additionally, how does the local climate in Vaughan impact these calculations, especially during extremely cold winters and hot, humid summers?

Issue:
I’ve recently noticed that my HVAC system is short-cycling, meaning it turns on and off frequently without reaching the set temperature. This has been causing higher energy bills and inconsistent comfort levels in my home. I’m unsure if this is due to an oversized unit, a thermostat issue, or if there might be another underlying problem. What steps should I take to diagnose the cause of the short-cycling and what potential solutions could resolve this issue?

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Replies

  1. shannalee | | #1

    Check Thermostat Settings:
    Ensure the thermostat is set correctly and is functioning properly.
    Consider recalibrating or replacing the thermostat if it's malfunctioning.
    Inspect System Size:
    Confirm whether the HVAC system is appropriately sized for your home. An oversized unit can lead to short-cycling.
    Review the results of the Manual J calculation if available.
    Examine Air Filters:
    Check the air filters for dirt and blockage. Clogged filters can restrict airflow, causing the system to short-cycle.
    Evaluate Ductwork:
    Inspect ductwork for leaks, blockages, or improper sizing. Poor duct design can affect airflow and system efficiency.
    Assess Refrigerant Levels:
    Ensure refrigerant levels are adequate. Low refrigerant can cause the system to malfunction and cycle improperly.
    In addition, you can reference: https://www.dependableair.com/blog/2024/july/choosing-the-right-size-of-hvac-system/ geometry dash lite

  2. davidkoperty | | #2

    To determine the right size of an HVAC system for your home in Vaughan, Ontario, consider factors like home size, insulation, windows, and climate. Consulting with a professional for a proper load calculation is key. For energy solutions, check out lpg gas company I-Maximum. They offer expert LPG systems, synthetic natural gas, and biogas installation services, with fast, reliable support and a focus on safety and efficiency​

  3. walta100 | | #3

    “My HVAC system is short-cycling, meaning it turns on and off frequently without reaching the set temperature.” This is an incorrect definition of short cycling.

    If you said my unit turns on and reaches the set point in a few minutes and then turns off without running long enough to remove much moisture from the air forcing me to lower the set point and now I feel cold and clammy. That would be the classic symptom for oversized

    If you unit is truly shutting off without reaching the set point you need to have the unit repaired. Seems unlikely but make sure you filter is clean and your register are all open and unblocked.

    An oversized system that is short cycling generally does not make it use noticeably more energy usage. Yes, it is hard on the equipment and dehumidification will be a problem in hot and humid climates. I do not think of Canada as hot and humid in the way Florda is.

    Walta

    1. Expert Member
      DCcontrarian | | #4

      The area around Lake Ontario can be quite humid in the summer.

      How can you tell observationally if the AC is right-sized? It should be sized to provide adequate cooling at the design temperature, which is the 99th percentile temperature. So you need to find out what that is. Then you need to wait for a day when it's that temperature out, and observe the system's behavior. It should be running continuously or almost continuously, and it should satisfy the thermostat.

      Since it will probably be a year or so until you hit your design temperature, there is an analytical method called a Manual J, where you enter in the dimensions of your house and details about its construction and it estimates the cooling load at the design temperature. You then compare it to the size of the installed equipment.

      You can get an idea of your heating design load from your fuel usage following the process in this article:
      https://www.greenbuildingadvisor.com/article/replacing-a-furnace-or-boiler

      From the heating load, you can estimate the cooling load.

  4. freyr_design | | #5

    I’m pretty sure this is a bot, it reads a lot like a bot. I’m pretty sure if you typed his question into Google you would get a very thorough explanation

    1. FrankD | | #6

      And just by coincidence I'm sure, the OP has the exact same name as an HVAC contractor in the city mentioned.

      1. freyr_design | | #7

        It seems like they should have done that in the reverse, random asking question, contractor answering it. Makes you not have much faith in the hvac contractor if they are asking this….

      2. Expert Member
        DCcontrarian | | #8

        I'm not impressed that a HVAC contractor would think square footage is a factor in cooling load.

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