Homeowner Guide For Breathing Easy During Wildfire Season, Even When The Power Goes Out

Ahh, those scorching days of summer, when it seems like your air conditioning system never stops running. And that’s even without wildfire smoke in the air.

Dog days of summer. Photo by Rafał Karoń on Unsplash

But the unfortunate truth is that we now have a regular wildfire season on top of the summer heat, which usually means weeks of poor air quality and the threat of electrical service disruptions whenever power utility companies see elevated fire risks.

These conditions affect millions of people in the western Pacific states, as well as a growing number of regions in other parts of the U.S. affected by drifting smoke from U.S. and Canadian wildfires.

But homeowners are not defenseless. In this article we’ll look at how to improve and protect the living treasure of cool, clean air you and your family need to breathe in your homes.

How To Ensure Good Air Quality During Wildfire Season | Planning Strategically

The key factors are whether or not there’s smoke in the air, and whether or not electricity is available from the local power grid.

Homeowners need to plan for 4 Conditions:

Each of these 4 conditions has its own challenges, but the hardest one is when it’s smokey outside and you have no power. 

But if you know what to do and you have a plan you’ll still be able to breathe clean air and stay cool.

When the power is off, homeowner options change.

Now let’s get into the weeds.

Situation 1: Clear hot weather with no smoke and full power availability

Your home’s HVAC system is similar to the human respiratory system. It takes outside air into the body (or home), filters it, humidifies it, and brings it to the right temperature.

After the body (or home in our case) uses the air, it sends it back outside, then keeps repeating the cycle with more fresh air. 

How to Control the Temperature, Humidity and Cleanliness of the Air in your Home

Let’s look at some of the ways you can improve your indoor environment when it’s hot outside.

If you’re smart about it, you can do this without throwing money at your HVAC system.

1. First, use what God gives you

Maybe you’ve thought about running your air conditioning 24/7, just to get some relief from the heat, but it’s expensive and it may be unnecessary.

If it’s cooler at night where you live then you can save electricity costs, wear and tear on your HVAC system and get some fresh air by opening up the windows and letting nature cool your home. Just close them back up in the morning before it starts to get warm.

If you need to keep bugs, critters or people out you can screen your windows or use security bars.

During the heat of the day keep your windows closed, draw your blinds or close your curtains, and if you can cover your windows from the outside of your home do that too.

If you don’t run your air conditioner your house will still heat up, but not as much. If you do run your air conditioner it won’t have to work as hard to cool your home.

2. Plug the Drafts

Plug the physical leaks:

Air leaks in your home are usually found coming through your doors or windows. These drafts can be plugged with weather stripping or caulking.

Plug the thermal leaks:

Your biggest thermal leaks are likely to be at your windows, your home insulation (or lack of insulation) and your roof.

Single pane windows can waste up to 30% of a home’s cooling capacity according to the Dept. of Energy. Upgrading single pane windows will usually pay for itself within months, up to a couple years.

Imagine a sizzling summer day with sunlight pouring into your home. If you have energy efficient windows they will let visible light in, but reject heat-producing infrared light. With less heat coming into your home your air conditioner won’t have to work as hard, helping you save on electricity costs.

Double glazed, triple pane and low emissivity windows are not cheap, but if you run the numbers they may pay for themselves over time by keeping your home cooler without having to run your air conditioner as much.

3. Filter Up

You know the air filters you use in your HVAC system help to clean the air you breathe. But they also make your system run more efficiently.

If you forget to change your air filters for a month or longer you’ll notice that they start to change color as they get dirtier and dirtier.

The dirtier your air filters get the harder your HVAC system has to work to push air through. That means higher electricity use and bigger power bills.

It also means your HVAC system may break down easier and not last as long.

What you may not realize is that as your air filters get dirtier they have a harder time keeping your air clean. This can lead to health issues, especially for kids, older adults or people with allergies.

How often should you change your home’s air filters?

At least four times a year, once for each season. 

Possibly more often:

• if you or family members are sensitive to allergens or pollutants, 
• if you have pets, 
• if you have young children or elderly in your home
• if you’ve had wildfires and smoke in your area

Wildfire smoke degrades the effectiveness of air filters, so it’s recommended to change filters after any smokey periods.

What type of air filter should you use in the summer?

Depending on your location summer weather often means more dust and pollutants in the air.

The cheapest fiberglass air filters will protect your HVAC system from airborne debris, but they don’t clean your air very well.

For clean air a polyester or cotton pleated filter with a MERV rating of at least 8 or 10 is recommended. For people with respiratory conditions a MERV 11, 12 or 13 filter will capture as much as 90% of particles as small as 3.0 microns.

What type of air filter should you use if you’re expecting smoke in the air?

Depending on your location summer weather often means more dust and pollutants in the air.

Bare bones fiberglass air filters will protect your HVAC system from airborne debris, but they don’t clean your air very well.

For clean air a polyester or cotton pleated filter with a MERV rating of at least 8 or 10 is recommended. For people with respiratory conditions a MERV 11, 12 or 13 filter will capture as much as 90% of particles as small as 3.0 microns.

Filters with a MERV rating of 13 or higher are recommended by the Environmental Protection Agency for smokey conditions. 

That’s setting the bar pretty low, however. At best MERV 13 filters can only trap 75% of smoke particles sized 0.3 – 1.0 µm in size.

And it’s the small particles that are most dangerous. According to Yale Medicine, these tiny smoke particles go right through your body’s normal defense mechanisms, penetrating deep into your lungs and even into your bloodstream.

These particles are linked to:

• Impaired lung function
• Bronchitis
• Asthma attacks
• Heart attacks
• Stroke
• Lung cancer
• Reduced cognitive function  

HEPA filters, or high-efficiency particulate air filters are designed to remove nearly 100% of airborne particles as tiny as 0.3 µm in diameter. That makes them an even better fit for removing fine ash, soot and other microscopic wildfire smoke particles.

Using a HEPA filter in your HVAC system can protect the quality of the air you breathe in your home, even more than a MERV 13 filter. 

The biggest drawback is that higher rated MERV filters and HEPA filters create more resistance against airflow in your HVAC system. That back pressure can cause damage to some older or lower power HVAC systems. 

So, it’s good practice to consult with a heating and cooling professional before installing any filter with a MERV rating higher than 8.

If your air conditioning system can’t handle a MERV 13 or HEPA filter then an air purifier may be your best option. There are many air purifiers, including portable ones, that come with HEPA filters.

Benefits of air purifiers over standard HVAC systems include:

– Enhanced Air Filtration: Air purifiers typically use HEPA filters that capture finer particles than standard HVAC filters, removing more allergens, dust, and pollutants from the air.

– Targeted Air Cleaning: Air purifiers can be placed in specific rooms where air quality improvement is most needed, providing a more targeted approach than a whole-house HVAC system.

– Improved Allergy Relief: By removing pollen, pet dander, and other allergens more efficiently, air purifiers can significantly reduce allergy symptoms for household members.

– Reduction of Asthma Triggers: Air purifiers help to reduce common asthma triggers such as dust mites and mold spores, providing a healthier breathing environment for asthma sufferers.

– Odor Elimination: Many air purifiers come with activated carbon filters that effectively remove odors from cooking, pets, and smoke, something standard HVAC systems often cannot do.

– Less Maintenance: Air purifiers generally require less frequent maintenance compared to HVAC systems, making them easier to manage on a day-to-day basis.

– Portable and Flexible: Unlike HVAC systems, air purifiers are portable and can be moved from room to room as needed, providing flexibility in improving air quality in different parts of the home.

– Lower Energy Consumption: Air purifiers typically use less energy compared to running an entire HVAC system, which can lead to cost savings on energy bills.

– No Ductwork Required: Air purifiers don’t require ductwork, making them a great option for homes without central HVAC systems or for renters who can’t install permanent systems.

– Advanced Technology: Many modern air purifiers come with advanced features like air quality sensors, app connectivity, and auto-adjusting settings, offering more control and convenience than traditional HVAC systems.

4. Tax Credit Up

What could be better than having the government pay you to improve the energy efficiency of your home?

You may still decide it’s not worth the investment right now, but if you’re on the fence about making energy improvements to your home this could make the decision easier.

Situation 2: Clear hot weather, but there’s no electrical power from the grid

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When the power goes out

These things happen. Even if there’s no smoke or fire your utility company may de-energize power lines as a precaution during times of heightened wildfire risk. 

This can happen anywhere within utility service areas to reduce the risk of sparking new fires, a practice known as Public Safety Power Shutoffs (PSPS).

If it’s a rare occurrence then normal emergency preparedness may be all you need. Just make sure you always have:

• Water
• Food
• First aid supplies
• Prescription medicines
• Batteries

But, what if power shutoffs become the new normal?

In the last few years, aging power grids have been involved in highly destructive wildfires in Hawaii, California, Oregon, Texas and Minnesota. 

In many cases the utility companies are being held responsible, to the tune of hundreds of millions of dollars in lawsuit awards.

If you live in a high wildfire risk area of the United States you may expect utility companies to shut your power off when wildfire risks are high.

Don’t forget the Basics

The basics still apply, as described in the section above. Use what God gives you to keep your home from heating up. Then your situation won’t be as dangerous when the electricity goes out and you can’t power your AC.

Power Outage Preparedness Plan

Do you have a plan for when the lights go out?

Here’s what goes into a preparedness plan:

• Things you can do before a power outage
• Things you can do during the power outage
• Stuff you can buy to make your power outage plan a success
• Safeguarding your medical needs in a power outage

Things you can do before a power outage

• Create a back-up power plan
• Make a place to cook outdoors
• Build a do-it-yourself swamp cooler
• Plug the leaks that let hot air into your home (see details in Case 1, above).
• Stock up on emergency supplies, food and water and emergency equipment.
• Keep ice packs in your freezer to keep food cold during an outage.
• Create a fire break defense around your home.
• Plan a wildfire evacuation route.
• Make a plan for watering and feeding your pets or any livestock.
• Make a plan to go to a shelter, other family members or friends if you are forced to evacuate.

Things you can do during a power outage

• Close the windows, draw the blinds. Ideally cover windows from the outside of the house.
  • It’ll still get hot by the end of the day, but not by as much.
• Close off the hottest rooms in your house, including ones that get lots of direct sunlight. 
• Keep the fridge/freezer closed. 
• Don’t cook indoors.
• Use bamboo fiber or cotton sheets to wick off moisture from your body to stay cooler in bed.
• Use a battery powered portable fan to cool you down, especially if you are damp.
• Take a cold shower, a bath, or go swimming.
• If the heat is dry, evaporative cooling can lower the temperature as much as 20 degrees Fahrenheit. That’s what “swamp coolers” do, but if you have no power, just put on a cotton t-shirt and wet it down.
• Hanging wet sheets around your house cools the surrounding areas as the moisture in them evaporates.

Stuff you can buy to make your power outage plan a success

• A power outage emergency kit
• A backup power generator
• A backup solar power system

Want to know what belongs in a power outage emergency kit?

First aid kits, bottled water, flashlights, batteries, a radio, backup prescription medicines, car chargers for phones and electronic devices, and a list of emergency telephone numbers for starters. You can get more ideas by searching “Emergency Zone Power Outage Emergency Kit” on Amazon dot com.

Backup Power Generators

A generator backup power system can be an effective and reliable way to keep the lights and cooling on during power outages, especially during emergencies like wildfire events.

When considering backup power systems, especially in areas prone to wildfires, the safety of the fuel source is a critical factor. Here’s why we recommend propane generators over gasoline, focusing on issues with flammability, heat, and electrical safety.

Gasoline is a highly flammable liquid, which poses a significant risk during storage and use. In high temperatures, typical in wildfire-prone areas, gasoline can evaporate quickly, increasing the risk of vapor buildup, which can be ignited by a spark or open flame.

Gasoline must be stored in specialized containers and kept away from any sources of ignition. It also has a relatively short shelf life, leading to potential degradation and increased flammability over time.

While propane is also flammable, it is stored under pressure in a liquid state and is less volatile than gasoline. Propane leaks typically dissipate into the air, reducing the risk of fire as compared to liquid gasoline spills.

Propane does not degrade like gasoline, ensuring that the generator operates smoothly without the risks associated with stale fuel. This stability is crucial in emergency situations where generator reliability is essential.

Also, propane tanks are designed to withstand significant pressure and environmental conditions, making them safer for long-term storage. They are also more robust against environmental heat, reducing the risk of combustion compared to gasoline.

How Backup Propane Generator Systems Work

1. Power Outage Detection: When a power outage occurs, the automatic transfer switch (ATS) detects the loss of grid power and signals the generator to start.
2. Generator Activation: The propane generator starts and begins producing electricity within seconds. It runs on propane gas supplied from the storage tank.
3. Power Distribution: The generated electricity is sent through the electrical panel to power the home’s essential circuits. The system can be configured to prioritize critical loads, such as heating, refrigeration, medical equipment, and communication devices.
4. Automatic Shutdown: Once grid power is restored, the ATS detects the restoration and automatically switches the power supply back to the grid. The generator then shuts down until the next outage.
5. Fuel Management: The propane tank needs to be monitored and refilled as necessary to ensure the generator can operate during extended outages. Propane is a clean-burning fuel, which reduces the generator’s environmental impact.

During the 2019 California wildfires, many residents and businesses used backup propane generators to maintain essential services and stay connected with loved ones. These systems proved invaluable in navigating the challenges posed by prolonged power outages.

Backup Solar Power Systems

A home solar panel backup power system, often called a solar-plus-storage system, is an effective solution for maintaining electricity during power outages, such as those caused by wildfire events. This system combines solar panels, an inverter, and a battery storage unit to provide a reliable and sustainable energy source when the main grid is unavailable.

How Backup Solar Power Systems Work

1. Solar Energy Collection and Conversion: During the day, solar panels, also known as photovoltaic (PV) panels, absorb sunlight and generate DC electricity. An inverter converts this DC electricity into AC electricity, which is either used immediately to power the home or sent to a battery for storage.
2. Energy Storage: The battery stores surplus energy generated by the solar panels. This stored energy can be used during the night, on cloudy days, or during a power outage.
3. Power Outage Response: In the event of a power outage, the system automatically switches to battery power, providing electricity to the home. This process is seamless, with no interruption to the supply of electricity to critical appliances.
4. Recharging the Battery: The battery recharges during the day when the solar panels produce more energy than the household consumes. This cycle continues, ensuring that there is always a reserve of energy available.

Airspool Solar Powered Mini Split Heat Pump Air Conditioner

It’s possible to keep your home cool during power outages using solar power, without needing a whole-house solar power backup system.

A good example is Airspool, which offers a 12,000 BTU do it yourself easy installation ductless heat pump. This is a hybrid unit that works either directly from solar power or from the electrical grid or a generator.

Safeguarding your medical needs in a power outage

For those with medical needs, continuous power can be critical. Devices like oxygen concentrators, ventilators, and refrigerated medications require a stable power supply. Backup systems also keep communication devices like phones and radios operational, ensuring that people can stay informed and connected during emergencies.

If you or a family member has medical needs that depend on electricity for refrigeration or power then it’s even more important to have a backup power source.

It’s also even more important for medically vulnerable family members to have an evacuation plan, first for getting out, and second for a place to go.

Situation 3: It’s smokey and hot – but the power is still on

First, do everything you can to keep the smoke out.

Keep your doors and windows closed.

If you have to go in or out, open and close the door as quickly as possible. Better yet use a double entry location with an inner door and an outer door if you have one. For example, your garage or a mudroom.

Smokey air will still try to seep in around your windows and doors.

• If you can, caulk them or seal them
• If you don’t have caulking materials you can use painters tape, duct tape or put damp towels at the bottoms of your doors.

Breathing smokey air is not just about being uncomfortable. The ingredients of wildfire smoke can threaten your health and even your life.

Second, keep your air conditioner running in recirculation mode.

Your HVAC system will work to cool and filter the air in your home while it recycles it. Plus, even in recirculating mode, air conditioners also work to suck moisture out of the air. Dryer air lets you cool down more quickly. 

Most residential air conditioners are primarily designed to recirculate indoor air because it’s more efficient to cool indoor air than much hotter outside air.  

If your air conditioner has a fresh air intake mode just make sure it’s switched off when outside air is smokey.

Third, upgrade your air filter.

The biggest health risk from wildfire smoke is microscopic soot particles that you can’t even see.

Air filters are an important part of the HVAC systems in most homes. They remove many irritants from the air and improve overall air breathability. 

But most air filters are not designed for wildfire smoke. 

Wildfires throw off a range of air pollutants which include tiny particulate matter classified as PM 2.5. That means these particles are smaller than 2.5 micrometers (µm) in diameter.

These microscopic smoke bombs are so tiny that you can get them into your eyes or breathe them into your lungs without even realizing it. That is, until you start coughing, feel a sore throat coming on, have an asthma attack, experience heart or lung problems, have a heart attack or even die.

If you want to protect your family it’s essential to invest in an effective wildfire smoke air filter. 

The U.S. Environmental Protection Agency recommends upgrading to a MERV 13 or higher air filter during smokey conditions. MERV stands for minimum efficiency report value. 
Considering that most stock air filters are only MERV 1 to 4, a MERV 13 filter sounds like a pretty big upgrade. But even a MERV 13 air filter won’t capture any more than 75% of pollutant particles 0.3-1.0 µm in size.

Which begs the question . . .

Since the average particulate size for wildfire smoke is 0.3 µm, is a MERV 13 air filter good enough?

It might be if it’s also an electrostatically charged filter. Electrostatic designs allow MERV 13 air filters to capture smoke particles with an opposite electrical charge.

Electrostatically charged filters work well until they don’t.

As more and more smoke particles get captured, the filters they lose their electrostatic capturing potency. Which means you have to replace these filters more often, especially after wildfire events.  

With ordinary conditions, most homeowners should replace their HVAC filters every 30 to 90 days, depending on use and whether or not they share their living areas with pets.

But that rule of thumb goes out the window with wildfire smoke.

Even if you’re not using electrostatic air filters you should still plan on replacing them after a wildfire event. 

Ultimate filtration – the HEPA option

HEPA filters are very effective at cleaning smoky air. They are electrostatically charged, equivalent to MERV 17 or higher, and will trap 99.97% of air particles that are 0.3 µm in size.

A potential problem with using these high efficiency air filters, however, is that the better they get at filtering air, the more they restrict air flow. That means the higher the MERV rating the harder your HVAC system has to work to pump air through them.

That could become an even bigger problem if you forget to change your air filters regularly, since particulates will accumulate in your filters and make your system have to work even harder.

If you’re not sure if your air conditioning system can handle a MERV 13 or higher air filter please consult with an HVAC professional who can check your equipment for compatibility.

But, there’s an even more effective option.

Fourth, get a separate wildfire smoke air purifier.

Dedicated air purifiers can work together with your HVAC system to provide safe, clean breathable air in your home, even during wildfire events. And, by using an air purifier you won’t have to worry about whether your air conditioning system can handle the resistance of high efficiency air filters.

Don’t try to purify all the air in your home with a single purifier, however. Just put it in your bedroom or pick one room where you spend the most time during waking hours.

Use a purifier with a coverage area that’s a little larger than your room. That will let you run it at a slower, quieter fan speed, since purifier coverages are rated based on maximum fan speed. 

Air purifiers work really well, but they’re not cheap to buy off the shelf. There are more affordable options, however, that are just as effective.

Don’t have $500 for an air purifier?

Or, try this DIY upgrade version.

Basic ways you can prepare for wildfire season:

• Update your contact information with your power provider and sign up for alerts.
• Prepare a power outage kit, create a fire break around your home, and plan for medical needs.
• Consider a backup power source if you have medical equipment that requires electricity.
• Sign up for emergency notifications on your local emergency management or public safety website.
• And, of course, get or make a wildfire air purifier.

Air quality varies not only day by day, but even hour by hour. Monitor the Air Quality Index and take advantage of periods of cleaner air by opening the windows and doors when you can, especially in the morning when air quality tends to be better.

Use good filters in your HVAC system. After a wildfire event be sure to replace your filters, especially electrostatic air filters.

Even the smallest smoke particles will eventually fall out of the air onto the floors and other available surfaces in your home. If possible, it’s recommended to damp-mop your floors instead of vacuuming, to avoid the risk of blowing the particles back into the air.

Smoke byproducts will also accumulate on your clothes and skin, and even in your bed. To stay healthy, that means more showers, changing into clean clothes after coming in from outside, and more frequent washing of your sheets.

Situation 4: Hot and smokey, and no power

This is the worst right? It’s hot and smokey out, but you can’t turn on the air-conditioning (unless you’ve got your own backup power source).

Air quality conditions can change, however, not just from one day to the next, but even hour by hour.

If you regularly test or check the Air Quality Index you can take advantage of periods of cleaner air. Just open your windows and doors when the opportunity presents itself, such as in the morning when air quality tends to be better.

The Case for Backup Power

There are many things you can do to hold heat at bay when it’s smokey outside, but none of them are as easy or as quick as your choices with power. 

A backup generator can provide enough electricity to run an air conditioner as well as other household appliances. 

Note: Most fire safety services recommend against using gasoline powered generators during wildfire events or threats, because of the risks of sparks or potential exposure to combustion gases.

Propane or natural gas powered generators are considered safer. But the costs can range from a few hundred dollars to a few thousand.

If you’re not ready to invest that much money in a backup power generator system, you can still achieve survival mode air filtering and cooling using much cheaper batteries or solar panels as your power source.

Running an evaporative cooling system or a fan uses a lot less electricity than your air conditioner. In fact, fans only use around 1% of the amount of electricity used by air conditioners.

Power consumption for various home devices (typical)

Device	Power Capacity (watts)	Hours per Day	Power Needed per Day (kilowatt hours)
Air Conditioner	3500	24	84
Window AC	900	24	21.6
Ceiling Fan	30	24	0.7
Box Fan	50	24	1.2
Air Purifier	180	24	4.3
5 LED Light Bulbs	60	4	0.2
Refrigerator	500	8	4.0
Mini-Fridge	100	8	0.8
Microwave Oven	1500	0.5	0.8
LCD TV	250	4	1.0

Backup Power Budget Example 1: the “don’t cramp my style” plan

If you wanted to be able to run a central air conditioner, an air purifier, a refrigerator, a microwave oven, an LCD TV, and keep the lights on you would need to size your backup power system to handle around 90 – 100 kilowatt hours per day.

Satisfying that power need would require:

• A propane inverter generator rated 4500 to 5000 watts or higher.
• Or, a backyard full of solar panels, with a charge controller, multiple batteries for energy storage and an inverter (an average solar battery capacity is around 10 – 14 kilowatt-hours).

Backup Power Budget Example 2: the “survival mindset” plan

To make your backup power needs more manageable, trade the air conditioner for a box fan and the full size refrigerator for a mini fridge. 

If you do that you could get by with less than 9 kilowatt hours of power per day. That’s a lot easier and cheaper to create.

This range of backup power could be done with: A portable power station like Goal Zero Yeti, Bluetti or Jackery, with 400+ watts of solar panels for charging.

Cooling and Heating your Home with Science

You might think heating and cooling are opposites, but they’re actually related.

Your home is constructed of wood, metal, concrete and other materials, and it’s filled with air. The temperature of the air and all the materials in your home depends on how much energy they have. The more energy, the hotter the temperature.

So when you want to heat your home, you add energy, and when you want to cool it you take away energy.

Heat Transfer

When you want to cool your home you have 3 paths to work with:

• Conduction
• Radiation
• Convection

Conduction

When it’s hot outside, conduction works against you.  Conduction is how heat travels from outside to inside through solid materials, such as your windows, your walls or your roof.

The goal is to keep as much heat out as possible, using energy efficient windows, insulation or heat reflecting roofs.

Convection

Convection is the transfer of heat through air or liquid.

Air conditioners work mainly by convection, using refrigerants to absorb heat from indoor air and move it outside the house. 

Fans also cool by convection, but not as you might think. It’s more than just blowing air around.

When a fan blows air over your skin it causes moisture to evaporate. As the moisture evaporates it turns to water vapor, and at the same time it sucks heat from your skin. Fans are more efficient than air conditioners, because they only need to cool you down, not your whole house.

Fans only use about a hundredth of the electricity needed for air conditioners. That means you could run your fan for 24 hours and not use as much electricity as you would with 15 minutes of air conditioning. It also means you could buy a solar powered fan for less than $100, and run it without a battery as long as the sun is shining.

Radiation

Radiation is heat traveling by electromagnetic waves in the form of visible light or infrared light. The best example is the light and heat we receive from sunlight, which reaches us directly from the sun through the vacuum of space.

Low emissivity windows are designed to reflect away infrared radiation coming from outside. Window shades can also partially block radiation heating.

The walls or ceilings of your indoor rooms can also radiate heat, making you feel warmer.

Thermal Mass

Thermal mass is about how much heat energy a material can absorb or store. 

If your house is hot and you turn on your air conditioner it takes time to remove the heat energy and cool your house down, even by only one degree.

Cooling the air inside of your home is not enough, because there’s more thermal mass in the walls of your home than in the interior air. Until you cool them down, the walls of your home act like heaters to the inside air, counteracting the cooling air from your air conditioner.  

The denser materials in the walls, floors and ceilings of your home have high thermal masses, and it takes time to cool them down.  

Of course, the reverse is also true. If your house is cold, it takes a lot of heat energy and time to warm it up. 

That’s why if you’re able to cool your house down at night, it takes a lot longer to heat up the next day, and your air conditioner doesn’t have to work nearly as hard.

Cooler By Design

Air conditioners are wonderful inventions, but they need a lot of energy, and that means they’re not cheap to run.

Air conditioners are not the only way to keep your home cool, however. For hundreds and even thousands of years different cultures have taken advantage of the thermal properties of various materials and the physics of heat transfer. And they didn’t need a college degree to figure it out.

So if you want a cooler home, consider alternate approaches. Some of these methods require designing your home from the ground up, but others can be taken advantage of without extreme makeovers.

Making it Cooler from the Top

A hot roof or a hot attic is like inviting the heat of the sun to come into your home and never leave. Even with insulation. It also blocks the most natural escape route for any hot air that has built up in your home. 

An average gray tone roof only reflects about 20% of incoming sunlight. The remaining 80% of the sunlight pours solar energy into the roof, raising its temperature by as much as 69°F hotter than the outside air. 

By comparison, a bright, smooth, clean white roof surface can reflect as much as 85% of sunlight, resulting in a surface temperature that’s only about 9°F hotter than the air.

Other than the cost of the white roof coating, that’s free heat relief, meaning you could be a lot less dependent on expensive air conditioning.

Even cooler than a white roof is a green roof, as in living greenery.

The YouTube video above also describes cooling using a ground source heat pump (or geothermal heat pump) and cooling by ventilation.

Because of the cost of installation and relatively long payback period, ground source heat pumps are not for every homeowner. In contrast, the costs of ventilation cooling are so low every homeowner can use it.

Making it Cooler in the Attic

Between your roof and your ceiling, your attic could be the hottest part of your house, getting as hot as 150°F in the summertime. That extra heat could be driving up your air conditioning costs by as much as 40%.

If you do nothing else you need to make sure the base of your attic is insulated, at least to level R-30.  The U.S. Department of Energy recommends between R-30 and R-60 insulation in the attic, depending on the region in the U.S. where your home is. 

That’s why an attic fan could save you a boatload of money in lower air conditioning costs during the hottest months of the year.

You don’t have to run an attic fan all the time. Even running it during the hottest part of the day, using an adjustable thermostat, could reduce your attic temperature by up to 50° F. And that could mean reducing the temperature in the rest of your home by up to 10°F.

Wind-Powered Turbines (Whirlybirds)

Have you ever seen those metal, turban-shaped rooftop fans that spin whenever there’s a breeze? These engineering marvels are best friends to homeowners wanting to save money on their cooling bills. 

As long as there’s a breeze – and it doesn’t have to be much of a breeze – they help suck hot air from your attic without using any electricity to power them. Even though they’re not as powerful as electric or solar fans, they still provide a lot of cooling benefit.

Cooler around the House

Planting trees, shrubs, and other greenery around your home is a natural and effective way to keep it cooler during the summer and reduce your air conditioning costs. This practice, called landscaping for energy efficiency, offers numerous benefits beyond just making your yard look nice.

Trees and shrubs work like natural air conditioners. They provide shade and release moisture into the air through a process called transpiration, which cools the surrounding area.

By planting strategically, you can lower the temperature around your home by 3 to 6 degrees Fahrenheit.

Energy Cost Savings:

The cooler environment created by plants means you rely less on your air conditioner, which saves you money.

The U.S. Department of Energy says that well-placed trees can cut up to 25% of your cooling costs. This could mean savings of about $100 to $250 a year, depending on your home’s size, local climate, and energy rates.

Environmental and Health Benefits:

Besides cooling your home, plants improve air quality by filtering pollutants and providing oxygen.

Practical Tips:

• Tree Placement: Plant deciduous trees on the south and west sides of your house to block the summer sun. In winter, their bare branches will let sunlight warm your home.
• Shrubs: Use shrubs and vines near walls to create layers of air that insulate your home, reducing heat exchange.
• Maintenance: Choose native or drought-resistant plants to cut down on water use and maintenance needs.