Furnace Draft Pressure Explained
Draft pressure describes the combustion-air and vent pathway at a defined test point. It must be interpreted with the model, vent, inducer and condensate system.
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AC Condensate Output: Why There Is No Normal Gallons per Day
AC condensate changes with indoor moisture, outdoor dew point, airflow, runtime and drain condition. Learn how to evaluate water removal without a fixed target.
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Window Heat Gain and AC Sizing: Why Glass Changes the Load
Window heat gain can increase AC load because glass adds solar gain and conductive heat that square footage alone misses.
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Furnace Blower Runs but the Burners Do Not Ignite
If the furnace blower runs without burner heat, separate FAN ON, post-fault cooling, and a failed ignition sequence before replacing any part.
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Heat Pump Outdoor Unit Iced Up: Normal Frost or a Defrost Problem?
Learn how to distinguish normal heat-pump frost from persistent ice, what defrost should look like, and when drainage, fan or control problems need service.
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How Infiltration Raises Indoor Humidity During Summer
Wind, stack effect and pressure differences can pull humid outdoor air through enclosure leaks. Learn how infiltration becomes a measurable moisture load.
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Furnace Combustion Analysis Explained
Combustion analysis evaluates a furnace using a coordinated set of flue, draft, fuel and airflow measurements. One efficiency percentage is not enough.
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Saturation Temperature in HVAC Explained
Learn how refrigerant pressure maps to saturation temperature, why line temperature is different, and when dew or bubble references matter.
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4 Ton Cooling Capacity Explained: BTU, CFM, and Delivered Cooling
A 4 ton AC is nominally 48,000 Btu/h of cooling capacity, but delivered cooling depends on conditions, airflow and installation.
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Furnace Starts Then Shuts Off After a Few Minutes
A furnace that lights and stops early may be losing flame proof, opening a limit, or ending the heat call. Use timing and safe observations to narrow it down.