Thursday, December 30, 2021

New Year’s Resolutions for your HVAC

New Year's is just around the corner, which means it's time to write those New Year's Resolution lists! It's a fun activity that helps start the year with purpose and goals to pursue. Usually resolutions are about health, finances, and good general habits... But what about your HVAC system? Royal Heating & Air is bringing you some great resolutions for 2022. Get ready to have the best heating and cooling at the Lake of the Ozarks

Do a Deep Clean

Doing a deep clean throughout your home can help give you a fresh start and make the new year feel even newer. With a clean house and a fresh outlook, you'll be unstoppable! Part of your deep clean this year should be your HVAC system. After all, the air you breathe inside your home is filtered through your HVAC system over and over again. If your ducts are full of dust, dirt, dead bugs, and even mice, then just imagine what you're actually breathing. 

It's a good idea to get your HVAC ductwork cleaned professionally at least every 5 years. If you have allergies or asthma, then it might be a good idea to get them cleaned more often - as much as necessary. One incredible way to keep your HVAC system free from bacteria and viruses is to install an HVAC UV Light System! These systems prevent pathogens from reproducing so they can't spread and get you sick. It works constantly in the background, giving you cleaner air and peace of mind. Royal Heating & Air can install one for you, just give us a call to learn more!

Another simple way to make sure the air in your home is as clean as possible is to regularly change your air filters. Air filters should be changed according to their type and amount of use, but on average filters need to be changed every 30 to 90 days. Having a clean air filter is crucial to maintaining good indoor air quality. If your air filter is dirty, then your system will have a hard time pulling clean air through it. This can negatively affect your system's efficiency as well as your immune system, making it harder for your body to fight off infection. Check your air filter every month to make sure it hasn't accumulated too much dust and debris.

Don't forget outside! Check your outdoor unit to make sure there aren't any leaks, damage from storms or animals, bad smells, or loud noises coming from the unit. It's also important to make sure the unit is clear from any debris like dead leaves, snow, fallen branches, etc. We recommend that there should be at least a 3-foot clearance around the entire unit.

Improve Efficiency 

Efficiency isn't just a popular buzz word when it comes to your HVAC system. High efficiency saves you money in the short-term and the long-term. In the short-term, your energy bill will be lower if your system is running at it's best instead of struggling to keep up because it's having issues. In the long-term, your HVAC system will typically last longer if it has been able to operate at top efficiency for its whole life. Your units may need to be replaced earlier than expected if they haven't been well cared for during their use. 

To improve efficiency, make sure your airflow is at its best. Check to see if air is escaping through gaps and cracks in your ductwork. On average, about 20-30% of air that flows through air ducts escapes through cracks in the ductwork. According to the U.S. Department of Energy, “Sealing and insulating ducts can improve the efficiency of your heating and cooling system by as much as 20 percent.” This could be a great way to save on energy and have a more comfortable home in 2022. 
If you haven't already, you should also consider a programmable thermostat. Not only are they convenient, but they are also cost-effective. Programmable thermostats allow you to easily control the temperature of your home around the clock, whether you’re home or away. Smart thermostats provide energy savings by learning your unique schedule and temperature preferences and adapting to them.

Work with the Best

Instead of trying to DIY solutions to your HVAC issues or calling someone to help that isn't reliable, turn to the best HVAC company at the Lake of the Ozarks! Working with Royal Heating & Air in 2022 should definitely be on your new year's resolution list for your heating and cooling next year. Our technicians are skilled, on time, and care about you and the comfort and safety of your home. 

Give us a call to schedule a maintenance check on your HVAC system, have us come perform a Home Comfort Check, or have us install great technology to improve your home's sanitation, efficiency, and humidity. We've got what you need! 

Royal Heating & Air - "The King of Comfort"

Visit our website:

CALL TODAY! (573) 480-4313

Thursday, December 23, 2021

Buying a New HVAC System – The Answers to All Your Questions!

A good HVAC system can make or break your home comfort. Imagine sweltering summers with no air conditioning, or frigid and icy winters with no heat... Missouri weather can be brutal and you need a great system to keep up with it. If yours is struggling and it's time for a new one, or you're building a new house altogether, Royal Heating & Air is the best HVAC company at the Lake of the Ozarks and we are here to help! In today's blog, we're answering common questions when it comes to buying a new HVAC unit. Keep reading to find out! 

Should I Replace All the HVAC Equipment at Once?

If only part of your system goes out, it's possible that you won't have to replace the entire system. However, we recommend that when you replace one, it can be a good idea to replace both. Typically, AC units and furnaces are installed at the same time. That means if one goes out, it won't be long before the other one wears out too. If you are spending money to replace part of the unit, you deserve to have the peace of mind that your entire system is updated and running efficiently! You will also save money by only having technicians come out once instead of twice. Plus, in the long run, you'll save money with improved efficiency all around.

What Size System Do I Need?

Determining the right size for your HVAC system is important. If you buy a system that is too large for your home, you'll be wasting money. But, if you buy one that's too small, it won't keep your home at a comfortable temperature. You want to buy one that's just right! One way is to determine the proper size for your unit is to determine how many BTUS of heating and tons of AC you will need. You can figure that out by using the square footage of your home. There are several useful charts that can help you factor the right BTUS for your home's square footage. If you are between sizes, we recommend going up in size. You can also give your local HVAC expert a call: 573-480-4313. We would be happy to help you determine what size system would be right for your home!

How Long Does Installation Take?

Each home and situation is different, so we recommend that you get a specific quote to determine an estimated timeframe for installation. After you find the right unit for your home, we determine whether or not we need to order the system or if we already have it in stock. The actual installation time varies depending on the home's specifics and what is needed to install the unit. For example, will the system need new ductwork also? Installation in homes with ductwork already installed typically takes a full day. However, if we need to add the ductwork, vents, and other HVAC equipment, it could take longer. On existing homes, the old unit has to be removed before the new one can be installed, so it could take up to a couple days for the entire process. There are a lot of variables! Give us a call and we can help evaluation your situation and give you an accurate quote.

What is a SEER Number?

SEER stands for Seasonal Energy Efficiency Ratio. It is a measurement of an air conditioner's cooling capacity to the power input. It is a rating to show how efficient the system will perform and it is given by the manufacturer. When you purchase a unit, typically the higher the SEER rating the more efficient the unit will be. Always choose the higher SEER rating when given a choice.

How Do I Qualify for Rebates?

Rebates change from year to year, so always ask before purchasing your unit to see if it qualifies. Most rebates only qualify on existing homes and not for rentals or new construction. We can help you navigate through all your questions before purchasing your next HVAC unit.

Best Heating & Cooling Company 

At Royal Heating and Air, we pride ourselves on being The King of Comfort! As the best HVAC company at the Lake of the Ozarks, we are here to help with all your heating and cooling needs. Give us a call to learn more or schedule an appointment! 573-480-4313

Royal Heating & Air - "The King of Comfort"

Visit our website:

CALL TODAY! (573) 480-4313

Monday, December 20, 2021

Should I Switch to a Heat Pump? 𝘍π˜ͺ𝘯π˜₯ π˜–π˜Άπ˜΅!

Have you heard that heat pumps could be more effective and efficient, but you're not sure if it's the right choice for you? Royal Heating and Air is the best HVAC company at the Lake of the Ozarks, and we have the answers for you! For some, installing a heat pump could make a big positive impact on your energy costs and system efficiency. For others, it might be best to keep their current system. Keep reading to find out which group you're in! 

Heat Pumps, Explained

Heat Pumps are all-in-one heating and air conditioning systems. They are unique from a traditional furnace in that way – they can also be used for cooling! Basically, heat pumps transfer heat from one place to another. When they're operating to heat your home, they transfer heat energy from outside (from the air, the ground, or water) to the interior of your home. When a heat pump is operating to cool your home, it's transferring heat from inside your home, circulating it over cooling coils, and blowing the cooled air back into your house (similar to how a traditional air conditioner works). 

PROS: Why You SHOULD Get a Heat Pump

A great benefit to using a heat pump is that they are an energy-efficient way to both heat and cool your home. This is because of the way they function, by drawing heat from the environment as a source of renewable energy. Also, having one unit to service instead of both an air conditioner and a furnace could help cut costs over time.

You can also combine a heat pump with a furnace for a hybrid heat system in climates that get below freezing regularly and for long periods of time.

CONS: Why You Might NOT Want a Heat Pump

Some drawbacks to a heat pump are that they are working year-round and can wear out more quickly than an air conditioner. Again, heat pumps are doing the job of both the air conditioner and the furnace.

You may also notice that the system seems like it is always running, or that the air coming through the vent does not feel hot. This is because heat pumps provide a more constant flow of warm air over time, keeping your home at a constant temperature.

Heat Pump Maintenance Info.

To keep your heat pump happy, there are a few steps you’ll want to take...

Keep the thermostat set at a constant temperature. Frequently changing it could put an extra burden on your unit. If you do change the temperature throughout the day, try to limit it to twice a day. For example, when you leave work and when you return home.

Choose a temperature range that is manageable for your system – above 65 degrees in the summer and below 70 in the winter. Your system may have difficulty keeping up and could cause a frozen coil or condensation in the home in the winter.

Keep your heat pump as clean as possible. Remove snow build-up, ice, and any debris accumulating on or around the unit. Blockages can cause the system to overwork and begin to malfunction.

Schedule regular maintenance with Royal Heating & Air to ensure your heat pump is working efficiently. Your unit should be checked once a year at a minimum. It’s best to have us come out every season to ensure it is ready for the changing temperatures.

Pricing for Heat Pumps vs. Traditional Systems

To compare pricing on heat pumps and traditional HVAC systems, you have to consider several factors to know which one will cost you more in the long run. It's not just about upfront cost, it is also about efficiency and what it costs to run each type of unit where you live. Here in Missouri, that can be tricky. If you live somewhere that often has extreme heat and rarely gets below freezing, the heat pump is a no brainer.  But if you have more days below freezing days than above 90 degrees, then a traditional HVAC system may make more sense. In Missouri we get quite a mix. So another consideration is whether you need to replace the heating OR cooling part of your system... Or both. Because a heat pump can work as both a heating and cooling system for your home, it may be more cost-effective (especially in the short-term) to get a heat pump for your home. 

Best HVAC at the Lake of the Ozarks

Royal Heating & Air is the best heating and cooling company at the Lake of the Ozarks. We know all about heat pumps and whether or not one might be right for your home. So if you are considering installing a heat pump, we can schedule a time to evaluate your home’s heating and cooling needs and determine what is best for you. We are the king of comfort and are always on your team to provide for all your HVAC needs. We can't wait to help!

Royal Heating & Air - "The King of Comfort"

Visit our website:

CALL TODAY! (573) 480-4313

Friday, December 10, 2021

Make This Season Healthier with a UV Light System

It's about this time of year that everyone starts coming down with "a bug". Whether it's just a cold or actually the flu, no one likes getting sick. Royal Heating & Air has a great solution to help you stay as healthy as possible this season - Ultraviolet (UV) lights for your HVAC system! Today we're talking about how a UV light system works and why it's beneficial for your home and your health. Keep reading to learn more! 

What Does Ultraviolet Light Do? 

Ultraviolet (UV) light destroys the pathogens it shines on by deactivating their ability to multiply. That's right, simply shining UV light on bacteria and viruses can prevent them from replicating and overwhelming your immune system, making you sick. No harsh chemicals! 

UV Light for Coils

There are two types of UV lights available for your HVAC system. The first kind focuses on the components that are most prone to growing mold and mildew or other allergens and contaminants. The coils in your HVAC system have condensation that drips into a pan. This creates a humid, dark place... The perfect environment for mold and other harmful materials to grow. When air is circulated in your house through your HVACs ductwork, those germs get spread around and can reach every part of your home. By directing UV light at the coils with the proper intensity, those germs are killed and prevented from multiplying or spreading. In addition to providing cleaner air, your HVAC will also be more effective because the coils will not have buildup. This greater efficiency not only helps reduce your overall energy consumption, but it can also help extend the life of your HVAC system.

UV Light for Air Ducts

The second type of UV light for your HVAC is designed to focus on the air in your air ducts and to sterilize the air as it passes through. The positioning and intensity of the light can make a huge difference in its effectiveness. You will want to rely on a highly rated HVAC company. We will evaluate your home first to see if it is well-suited for a UV light. Then we'll handle the installation to make sure you get great results - and healthier air!

How Much of a Difference Does UV Light Make?

There are several benefits to having a UV light system installed in your HVAC. Most importantly, it helps increase the air quality in your home and could keep you healthier by destroying allergens, bacteria, and viruses before they cause issues. It makes such a big difference in air quality for our customers, that many notice immediately when the bulbs burn out and need to be replaced. 

What Substances Can UV Light Destroy? 

1) Allergens

If someone in your household suffers from allergies or asthma, air quality is extremely important to their quality of life. A UV light system can significantly help with this issue by eradicating common allergens in the duct work. You should notice that it feels easier to breathe and your lungs are less constricted than before.

2) Smells

Not only does the UV light reduce the number of bacteria in the air, but it also reduces smells and odors. When bacteria, viruses, and mold grow in your HVAC system, it can start to smell bad. Think about the moldy food you found in the back of the refrigerator... gross. Having UV light working for you to keep the air ducts free from contaminants can help improve the smell in your home.

3) Sickness

Are your family members sick all the time? It may be due to a medical condition, but it also could be because of a buildup of bacteria, viruses, and mold in your duct work. Breathing in these pathogens every day is harmful to anyone's health. Your body may get tired of fighting off so many potential illness and infections and become more vulnerable. One sleepless night or one stressful day could be all it takes for your immune system to be overloaded and no longer able to keep up. A UV light system can remove these harmful materials from your air ducts and ease the burden on your body.

Best HVAC Company at the Lake 

Want to give your immune system the best chance to stay healthy this cold & flu season? Give Royal Heating & Air a call to install a UV Light System in your home. It can help improve your HVAC efficiency and the air quality in your home! We can also help check-in on your furnace to make sure everything is working the way it should before it gets too cold. Call now! 573-480-4313.

Royal Heating & Air - "The King of Comfort"

Visit our website:

CALL TODAY! (573) 480-4313

Friday, December 3, 2021

Parades, Lights, Santa, Music... Don't Miss These Holiday Events!

Christmas is just three short weeks away! Get into the spirit of the season and enjoy a fun and entertaining December with these fantastic events around the Lake of the Ozarks. Royal Heating & Air loves being part of the Lake community and we are excited to help spread the news of these events to you so you can have the happiest season of all! Keep reading to find your favorites and add them to your holiday calendar!

(All event info sourced from as of 12/3/2021.)

Christmas Parades


Dec 4, 2021

Rock Island Park
E 8th Street
Eldon, MO 65026


Hours of Operation:

"The Eldon Christmas Parade and Celebration will be Dec 4, 2021 at Rock Island Park. The Parade will start at dark, and tree lighting ceremony will follow the parade."


Dec 11, 2021

Bagnell Dam Strip
1 Bagnell Dam Blvd
Lake Ozark, MO 65049

Phone: 573-434-3552

Hours of Operation:
1:00 pm

"Gather your business, club, talent, grass roots group, friends and family to join the festivities of the 37th Annual Lake Area Christmas Parade.

The parade kicks off at 1:00 pm. Line-up starts at 11:30 a.m. at the junction of HH & Bagnell Dam Boulevard.

Entries line up on 242 in the order they arrive. Judging of entries occurs before parade during line-up. Promptly at 1:00 the Maine Corp League Honor Guard leads the parade turning right on the Boulevard and proceeding down to Bagnell Dam.

Floats, boats, bands, cars, trucks, bikes, queens, celebrities, Shriners, firetrucks, marchers, twirlers, clubs, scouts, horses and more are anticipated to fill the ranks to make this a parade to remember. Entries forms are downloadable in the header above.

1st Place winner in each category (Business, Civic Organizations, Youth Groups which includes K-12 & Church Entries) will receive $100 award.

Best depiction of theme winner will receive a $200 award.

No full Santa costumes. Hats are okay.

Santa Claus arrives in Lake of the Ozark’s style. The parade finale. Pulled by his reindeer Santa’s ride is a beautiful Red Sleigh with over 2,000 lights, garland, music and Santa helpers. The sleigh was designed and built by Steve Lemens and his late wife Pat, who embarked on this labor of love for the joy of children at Christmas time. Many contributed to the original project. A special thanks to Steve Lemens, Brian and Angie Schuster, Summerset Boat Lifts and Big Thunder Marina for continuing this tradition.

Bring the whole family and join us immediately after the Parade at Luby’s Plaza where Santa will greet all the kids on Luby’s Stage with gifts for each. Enjoy the Sweets Table and Holiday Cheer!!"

(Photo Credit:

Holiday Lights Around the Lake


Nov 20, 2021 - Jan 2, 2022

Laurie Fairgrounds
1 Fairground Rd
Laurie, MO 65037

Phone: 573-374-4871

Hours of Operation:
Nightly 5:00 pm - 9:00 pm (10:00 pm weekends)

Get in the spirit and enjoy the beautiful drive-through light park! 


Nov 25, 2021 - Jan 1, 2022

Versailles City Park
Hwy 52
Versailles, MO 65084

Phone: 573-378-4634

Drive through the Versailles City Park for beautiful Christmas lights to get you in the holiday spirit. 


Nov 25, 2021 - Jan 9, 2022

Shrine of St. Patrick's Church
724 N Main St
Laurie, MO 65037

Phone: 573-374-7855

Hours of Operation:
5 pm - 10 pm Daily

"The Festival of Lights at the Shrine of St. Patrick, Hwy 5, Laurie, is the oldest light park in the area. It was started in 1981 with hundreds of lights decorating the buildings and grounds and has continued to grow each year. With 4,000 strings of lights, over 60 automatic timers and more than 350 extension cords, the Festival of Lights has turned into one of the major places to see. Instead of animated displays, the focus is on the true meaning of Christmas, Jesus and His Mother, Mary. There is no charge for this beautiful light display, it is simply our gift to the community."


Nov 29, 2021 - Dec 31, 2021

Osage Beach City Park
950 Hatchery Rd
Osage Beach, MO 65065

Hours of Operation:
5 pm - 9 pm

Enjoy a free display of holiday lights at Osage Beach City Park! 


Dec 4, 2021

Lake West
Laurie, MO 65037

Phone: 573-374-5500

Hours of Operation:
10 am - 7 pm

"There is no better way to get in the holiday spirit than watching the lake area come to life through its many light displays that are offered this time of year! The Lake West Chamber of Commerce is proud to be a part of this thriving area and to offer the information below for you and your family to enjoy these happenings throughout the lake area.

Join us for the Westside Christmas Walk! Tons of local businesses on the Westside of Lake of the Ozarks along Hwy 5 will be offering specials and promotions to help celebrate the holiday season, and Lake Vibes will have something special planned for the day!"

Christmas Experiences for the Kids (a.k.a. SANTA!!)


Dec 3, 2021 - Dec 4, 2021

Camdenton Square
1 Ct Cir NW
Camdenton, MO 65020

Phone: 573-346-2227

"Camdenton Christmas on the Square kicks off with a tree lighting ceremony on December 3, 2021 from 5:30 pm - 7:00 pm. There will be a Live Reindeer Display, Photos with Mrs. Claus, Hot Chocolate & Mulled Cider, and a performance by the Bell Choir.

On Saturday December 4, 2021 Christmas on the Square continues from 10:30 am - 1:00 pm. Santa arrives at 11:30 am. There will be Games & Prizes, Petting Zoo, Music, Nativity Scene, Crafts, Giveaways, Hot Dogs, Cookies, Hot Chocolate."


Dec 4, 2021

Central Ozarks Medical Center
3870 Columbia Ave
Osage Beach, MO 65065

Phone: 573-302-7490

Hours of Operation:

"Mark your calendars to bring your kids to chat with Santa and the characters from Toy Story such as: Woody, Buzz, Lotso, Forky, and Rex. Come enjoy this free event from 10am-12noon on December 4th. Special performance by the SOTO Upper Elementary All-State Children's Choir students."


Dec 4, 2021

School of the Osage
635 MO-42
Osage Beach, MO 65065

Phone: 314-660-7760

"The community is invited to the School of the Osage Middle School for the 41st Annual Holiday Bazaar from 9 a.m. to 3 p.m. Saturday, Dec. 4, 2021. Crafts, home dΓ©cor, jewelry and other unique items will be available to purchase from area vendors.

This event is organized by the Osage Family Partnership High School Tribe to raise funds for scholarships, student and teacher resources. Each year more than 100 booths are filled by vendors coming to showcase their exceptional crafts and other goods at this popular sale.

In addition, Santa will be on site for pictures and high school clubs will host a bake sale. Concessions will be available for purchase."


December 4th, 11th, and 18th

The Regalia Hotel & Conference Center
250 Racquet Club Dr.
Lake Ozark, MO 65049

Phone: 573-723-3000

Hours of Operation:
9 AM - 11 AM

"Pancakes with Santa! Every Saturday in December we will be hosting Pancakes with Santa Claus! Buffet is only $9.99! The breakfast will be hosted from 9 AM - 11 AM with optional activities during the breakfast and after! Prices may vary. CALL TODAY (573)-723-3000 for more info! Reservations are optional but recommended!"


December 4th, 11th, and 18th

The Regalia Hotel & Conference Center
250 Racquet Club Dr.
Lake Ozark, MO 65049

Phone: 573-723-3000

Hours of Operation:
11 AM - 3 PM

"The Regalia Hotel & Conference Center is hosting KIDS CHRISTMAS PARTY EVERY SATURDAY IN DECEMBER! Time for Christmas Cheer! The fun will begin after Pancakes with Santa at 11 AM! There will be concessions & a hot chocolate bar! CRAFTS & ACTIVITIES for the children! Prices may vary."


Dec 18, 2021

Camden County Museum
206 S Locust
Linn Creek, MO 65052

Phone: 573-346-7191

Hours of Operation:
11am - 2pm Santa, Play at 2pm

"Come to the Museum for a full day of fun for the family. Lunch with Santa & Crafts & Games 11am-2pm. At 2pm Young Museum Players presens "CSI" Christmas Scene Investigators Play - $5 per family."


Nov 27, 2021 - Dec 19, 2021

Old Kinderhook Resort
678 Old Kinderhook Dr.
Camdenton, MO 65020

Phone: 573-317-3500

"Join us November 27th–December 19th, 2021 every Friday, Saturday, and Sunday for Christmas Village festivities. This event is open to the public. Come join the fun! Please note, for all non-hotel guests, it is $5.00 per child to participate in the Christmas Village Activities.

Make plans to spend time with family and friends this holiday season as we kick off the holidays on The Ice at Old Kinderhook with family-friendly events and beautiful Christmas music. Create some great memories with your family and friends that will last lifetime.

Food, beverage, ice skating, and skate rental fees apply. Rooms available in The Lodge at Old Kinderhook. 573-317-4314 to speak directly to Front Desk Representative."

Caroling & Christmas Music Performances


Dec 5, 2021

United Methodist Church
210 Monroe St.
Versailles, MO 65084

Phone: 573-302-9219

Hours of Operation:
2:00 p.m. til 3:30 p.m.

"December 5, 2021 at 2:00 p.m. - The Greater Lake Area Chorale presents its Christmas Concert "Christmas Time is Here" at United Methodist Church, 210 Monroe St., Versailles, MO 65084. Admission is free, with a free will donation at each concert. Come enjoy the sounds of the season with the Chorale and their two new pianists, Michael Fulk and Cheryl Nichols. For more information, call Tracy Garrett, Director, at 573-302-9219."


Dec 8, 2021

Stark Caverns
125 Cave Drive
Eldon, MO 65026

Phone: 573-867-2283

Hours of Operation:
6:30PM - 7:30PM

"We are excited to announce this years return of Carols in the Caverns.

Experience a Stark Caverns holiday tradition with live performances, "inside the cave", from your favorite local community choir groups including Eldon High School Choir, Ninth Street Choir, and School of The Osage Choir. This is a great opportunity to support the community with 50% of ticket sales going back to support these organizations.

Tickets: $10 per person (advance online purchase required, tickets will not be available the day of the event)
Each performance will be about 30-45 Min Long.
Seating is limited so reserve your spot now!"


Dec 18, 2021

Various Location Around the Lake
Various Locations
Osage Beach, MO 65065

"An annual Community-Wide Event. We will be traveling around the Lake stopping at Nursing Home and Assisted Living Facilities singing Christmas Carols and Spreading Christmas Cheer!! All Are Welcome!!"

Happy Holidays at the Lake 

The Lake of the Ozarks is quickly becoming more and more of a year-round destination. Royal Heating & Air loves taking care of the Lake community. Whether you're a full-time resident or have a second home you love visiting throughout the year, we are here for you with the best HVAC services at the Lake of the Ozarks. Give us a call to schedule a maintenance check or learn more about how we can help you!

Royal Heating & Air - "The King of Comfort"

Visit our website:

CALL TODAY! (573) 480-4313