Heat Loss: Uncovering Hidden Heat Loss To Cut Your Energy Cost [2024 Guide]

Space heating is more than for comfort. It’s a matter of survival. Regulating your home’s temperature helps relieve various health problems, promotes restful sleep, keeps humidity in check, discourages mold growth and more. No wonder most homeowners are sure to pay that electricity bill on time.

Unfortunately, many of us unknowingly waste energy running heating, ventilation and air conditioning (HVAC) equipment. Even if you observe proper maintenance, you can still spend more electricity than you should due to heat loss.

How Does Heat Loss Occur in a House?

Heat loss usually occurs in your house in one of three ways — convection, conduction and radiation.

Convection is when heat travels through the movement of fluids — liquids and gasses. A cold beverage sweating after taking it out of the fridge on a summer day is conduction in action. The water vapor in moist air condenses into liquid water upon meeting the beverage’s colder surface.Conduction is when heat directly travels from one object to another. If you touch a pan on a stove while cooking, you’ll get hurt because it’s hot.

Radiation is when heat moves through electromagnetic waves. Fireplaces and wood stoves provide warmth because of radiant heat.

These phenomena can result in energy waste when the heat finally escapes your home through cracks and thermal bridges. Your thermostat detects when the indoor air goes above or below the target temperature. Then, it tells your HVAC to bring it to the ideal level.

Convection is typically the main culprit in heat loss at home. That’s why uncontrolled airflow can be a significant headache.

Ideally, your house should be an airtight building envelope. It should separate your indoor environment from the outside world. In reality, it may be leaking conditioned air out and drafts in. Moreover, heat loss can happen because of wind, stack, reverse stack and combustion and ventilation effects.

The wind effect is when the wind forces outside air into the house and pushes inside air out. The stack effect is when warm air expands, rises, and creates a high-pressure area near your home’s top. The reverse stack effect is when the high-pressure area is at your home’s bottom. The combustion and ventilation effect is when your home draws outside air in to replace the inside air your fuel-burning appliances use to support combustion.

What Loses the Most Heat in a House?

Heat loss can occur anywhere in your property. However, these five are usually the biggest offenders.


The average American home is timber-framed with hollow walls. Wood expands on heating and contracts on cooling. Perennial swelling and shrinking result in gaps the inside air uses to escape. Drafts can also use the cracks to seep into the house.

That’s why sealing is one of the elements of a complete thermal enclosure system. There’s a constant need to repair tiny gaps with caulk and large ones with carpentry work.

2.Glazed Doors and Windows

Operating fenestration units contribute a ton to heat loss. Even high-performance products can leak less than 0.3 cubic feet of air per minute per square foot. Lesser glazed doors and windows — especially the old ones — have weaker resistance to heat transfer due to poor insulation.

Weatherstripping operating windows can keep cold drafts out, but design limitations cause some units to be more prone to air leakage. Only casements are the closest to being airtight. They press the sash against the frame upon closing.


Uninsulated and underinsulated floors above unconditioned spaces are a drain on energy. They can be a building envelope liability with the space they cover. Carpets and rags can only do so much to retain heat. Conditioned rooms lacking underfloor insulation when it counts are bound to have a bottomless demand for central heating or cooling.

4.Joists and Studs

These structural timber members are conduits for heat to leak through the wall, floor and ceiling. Forgetting about them when you insulate your house is bad news for your purse. They secretly facilitate heat loss, neutralizing your insulation’s benefits in other home areas.

5.Adjoining Structures

Unconditioned home areas are an extension of the outdoors. Their indoor climate is closer to the outside world than your heated rooms.

Adequately insulating and sealing unheated attached garages, unfinished basements and uninhabitable attics is a must. If you’re talking about a garage, for example, you have to consider door thickness, material and insulation type when insulating. The metric for a garage door’s energy efficiency is its “R-Value,” and the general rule is that a higher R-Value provides better insulation.

Heat loss -home

How Do You Identify Heat Loss in a House?

Thermography is the key to identifying pockets of heat loss in your house. Thermal cameras are consumer-grade. The most popular ones are phone accessories connectable through Bluetooth. They use your mobile device’s screen to show a thermogram, revealing warm and cold spots in real time.

Energy auditors use thermographic inspection devices optimized for detecting thermal defects and air leaks in building envelopes. Examples include spot radiometers, thermal line scanners and thermal imaging cameras.

The simplest of them all is the spot radiometer. It measures infrared radiation one spot at a time. The thermal line scanner captures temperature variations along the line. The thermal imaging camera demonstrates heat leakage in two dimensions. This sophisticated device produces accurate and detailed results that meticulous home energy audits require.

If you want to know how much heat your home loses, consult a professional home energy assessor. A level-two detailed audit is the best way to see the whole picture and learn how to increase your house’s energy efficiency. This service costs hundreds of dollars — a necessary expense to save cash and reduce your household’s carbon footprint over the long term.

What to Do After an Energy Audit

An energy auditor visited your home and tested your HVAC system, insulation and more. Now what? Follow these three steps.

1. Read the Report

Check the contents of the home energy efficiency report. This document describes your energy use and notes repairs and upgrades you can do to save on utilities. The auditor can sit down with you to discuss the findings. Ask questions to ensure you understand everything. Learn how impactful each project is to know which ones to prioritize.

2.Implement the Changes

Take action. The sooner you address the causes of heat loss in your home, the better. Start with what you can do without professional help to quickly consume less energy and see positive results.

Heat loss- take action

3.Plan Your Budget

Improving your home’s energy efficiency can be expensive. Focus on high-impact projects to maximize your limited resources.


Heat can escape from your home right under your nose. The loss can be negligible, but it adds up over time. You can’t see the severity of energy waste in your house with guesswork. Scheduling a detailed home energy audit is imperative to identify and fix the problems immediately.

Frequently Asked Questions

What Causes Heat Loss in Homes?

Heat loss occurs when homes are leaky and poorly insulated. Check the complete guide to understand various types of heat transfer and the usual home areas that waste energy.

Why Is the Heat in My House Dropping?

Air leakage is the main reason your house’s heat level is dropping. Controlling airflow at home matters to attain energy efficiency. Read the guide from the top to learn about the building envelope and phenomena affecting airflow.

What Is the Best Way to Detect Heat Loss in a House?

Using a thermal imaging camera is the best way to detect heat loss in your house. Discover various thermographic devices in this guide.

Why Would a Homeowner Hire an Energy Auditor?

Hiring an energy auditor is vital to know the causes of energy inefficiency in your home. Review the guide to understand the merits of using an energy auditor instead of personally assessing heat loss.

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