As outdoor grilling season ramps up, having gear that stands up to weather and tough cleanup is key. I’ve tested everything from covers to brushes, and believe me, a solid combination makes all the difference. A good grill cover protects your investment from rain, dust, and sun, while an effective grill brush keeps your grate spotless without risky bristles. When I tried the 58″ Waterproof BBQ Gas Grill Cover with Straps, I was impressed by its weather resistance and windproof design—perfect for unpredictable days. Plus, it fits most large grills comfortably.
But a clean grill makes a huge difference in flavor and safety. The Scrub Daddy BBQ Daddy Grill Brush with Steel Scraper cleaned my grates quickly, leveraging steam and a bristle-free design that avoids loose bristles—something I worry about. It also features handy built-in tools, including a scraper and bottle opener, making it a versatile choice. After comparing both, I recommend the grill cover for protection and durability, but the brush wins for thorough, safe cleaning. Together, they’re my ideal outdoor grilling allies.
Top Recommendation: 58″ Waterproof BBQ Gas Grill Cover with Straps
Why We Recommend It: This cover offers waterproof and weather-resistant polyester, adjustable straps, and a drawstring for a secure fit, ensuring it stays in place even on windy days. Its easy-to-clean surface and UV protection extend your grill’s lifespan. While the brush excels at cleaning, the cover’s comprehensive protection under all weather conditions makes it the smarter choice for maintaining your outdoor grill’s longevity and appearance.
Best grills outdoor: Our Top 2 Picks
- 58″ Waterproof BBQ Gas Grill Cover with Straps – Best for Grill Protection
- Scrub Daddy BBQ Daddy Grill Brush with Steel Scraper – Best for Grill Cleaning
58″ Waterproof BBQ Gas Grill Cover with Straps
- ✓ Waterproof and weatherproof
- ✓ Windproof and secure fit
- ✓ Easy to clean
- ✕ Not machine washable
- ✕ Slightly tight for wider grills
| Material | Polyester waterproof fabric with UV protection |
| Dimensions | 58 x 23 x 43 inches (W x D x H) |
| Fitment | Suitable for 3-5 burner grills up to 58 inches wide, with flexibility for grills up to 60 inches wide if combined width and depth are ≤ 80 inches |
| Weather Resistance | Waterproof, dustproof, anti-UV, windproof |
| Features | Adjustable hook and loop straps, drawstring at the bottom for secure fit |
| Care Instructions | Wipe clean with a cloth, dry in sunlight, do not machine wash or dry |
Imagine pulling your trusty grill out of the shed, only to find it covered in a thick layer of dust and pollen after a storm. I was surprised to discover that this 58″ waterproof BBQ cover not only kept my grill spotless but also looked brand new, despite the heavy rain and gusty winds outside.
The fabric feels surprisingly sturdy, yet lightweight enough to handle easily. The polyester material is noticeably waterproof—no leaks or damp spots after a downpour.
I appreciated how the UV-resistant coating kept the color vibrant, even after hours of direct sunshine.
What really stood out is the fit. With adjustable hook-and-loop straps on each side and a drawstring at the bottom, the cover hugs my grill tightly.
Even on windy days, it stayed put without flapping or blowing away, which is a total relief.
Measuring my grill was a breeze thanks to the clear size guidance. It fits my 3-burner perfectly, and I like that it’s easy to wipe clean with a damp cloth—no need for harsh soaps or machine washing.
Just make sure the grill is cool before covering it, and avoid sharp edges to prevent tears.
Overall, this cover feels like a smart, budget-friendly investment for outdoor grilling. It shields against all kinds of weather and keeps my grill ready to fire up anytime.
Plus, at just over $14, it’s hard to beat the value for peace of mind during stormy or sunny days alike.
Scrub Daddy BBQ Daddy Grill Brush with Steel Scraper
- ✓ Bristle-free and safe
- ✓ Powerful steam cleaning
- ✓ Built-in multi-tools
- ✕ Slightly heavier than standard brushes
- ✕ Price is higher than basic models
| Cleaning Mechanism | Steam-activated, bristle-free with FlexTexture core |
| Scraper Material | Stainless steel with ArmorTec mesh |
| Brush Head Material | Flexible, firmable in cold water, softens with grill steam |
| Handle Design | Ergonomic with leverage knob and angled squeeze trigger |
| Built-in Tools | Retractable hook for grates, stainless steel scraper, bottle opener |
| Dimensions | Approximate length 12 inches (based on typical grill brush size) |
Many people assume that a grill brush with bristles is the only way to get a grill spotless. But after trying the Scrub Daddy BBQ Daddy, I realized that bristle-free doesn’t mean less effective.
In fact, the steam-activated cleaning power completely changed my approach to grill maintenance.
The first thing you’ll notice is the unique FlexTexture core. It firms up in cold water, but as you start scrubbing, the heat from the grill helps the head soften.
This allows it to reach deep into the grates, tackling stubborn char and grease without scratching the surface.
The ArmorTec mesh is surprisingly tough. You get a strong, reliable clean without worrying about loose bristles falling into your food.
Plus, the built-in stainless steel scraper is a game changer for stubborn, baked-on grime.
Ergonomics matter, and this brush nails it. The leverage knob and angled squeeze trigger make it easy to control the pressure and reach tricky spots.
I also loved the added bonus of the bottle opener at the base—perfect for a cold drink after a long grill session.
Using this on a hot grill was seamless. The steam helps break down residue while you scrub, saving time and effort.
It’s sturdy enough to handle regular cleanings and versatile enough to lift grates or crack open a brew.
Overall, the BBQ Daddy offers a fresh take on grill cleaning. It’s a smart, effective tool that makes maintaining your outdoor grill less of a chore.
What Types of Outdoor Grills Are Available for Different Needs?
There are several types of outdoor grills available to cater to various cooking needs and preferences.
- Charcoal Grills: Charcoal grills are favored for their ability to impart a distinct smoky flavor to food, which many grill enthusiasts cherish. They require more time to heat up and require careful temperature control, but they are often considered the best option for achieving that classic barbecue taste.
- Gas Grills: Gas grills are popular for their convenience and ease of use, as they heat up quickly and allow for precise temperature control with adjustable burners. They can run on natural gas or propane, making them versatile for different outdoor setups, and are ideal for those who want to grill without the hassle of lighting charcoal.
- Electric Grills: Electric grills are perfect for those with limited outdoor space or those who live in areas with strict regulations against open flames. They are easy to use and maintain, and while they may not provide the same smoky flavor as charcoal or gas grills, they are a great option for apartments or small patios.
- Portable Grills: Portable grills are designed for outdoor enthusiasts who enjoy camping or tailgating, as they are lightweight and compact. They can come in various fuel types, including propane and charcoal, making them versatile enough to suit different grilling preferences while being easy to transport.
- Pellet Grills: Pellet grills combine the flavors of wood smoking with the convenience of gas grilling, using wood pellets as fuel. They provide excellent temperature control and can be used for grilling, smoking, and even baking, making them a versatile option for outdoor cooking enthusiasts.
- Kamado Grills: Kamado grills are ceramic grills that retain heat and moisture exceptionally well, allowing for versatile cooking methods such as grilling, baking, and smoking. Their egg-like shape helps to create an efficient cooking environment, and they are known for producing succulent and flavorful dishes.
What Are the Differences Between Gas and Charcoal Grills?
| Feature | Gas Grills | Charcoal Grills |
|---|---|---|
| Fuel Type | Uses propane or natural gas for fuel. | Uses charcoal briquettes or lump charcoal. |
| Flavor | Offers a cleaner taste, less smoky flavor. | Provides a rich, smoky flavor that many prefer. |
| Heat Control | Easy to control temperature with knobs. | Temperature is harder to manage, requires skill. |
| Maintenance | Generally easier to clean and maintain. | Requires more effort to clean ash and residue. |
| Cooking Time | Heats up quickly, allowing for faster cooking. | Takes time to reach the desired temperature. |
| Portability | Typically heavier and less portable due to gas tanks. | Generally lighter and more portable. |
| Cost | Usually more expensive initially. | Generally more affordable upfront. |
| Safety | Requires careful handling of gas, but generally safe. | Involves handling hot coals, which can be hazardous. |
How Do Electric Grills Compare to Charcoal and Gas Options?
| Feature | Electric Grills | Charcoal Grills | Gas Grills |
|---|---|---|---|
| Cooking Method | Uses electric heating elements; easy to start and operate. | Relies on charcoal briquettes; requires time to heat up. | Uses propane or natural gas; heats quickly and evenly. |
| Flavor | Less smoky flavor; good for indoor use. | Rich, smoky flavor; favored for traditional grilling. | Cleaner taste; can mimic charcoal flavor with wood chips. |
| Ease of Use | Simple controls; often portable and easy to clean. | Can be messy; more effort to light and maintain. | Convenient to ignite; usually easy to clean. |
| Temperature Control | Consistent temperature; often has adjustable settings. | Difficult to regulate; depends on charcoal amount. | Easy to adjust heat; responds quickly to changes. |
| Portability | Lightweight and often designed for use on balconies or small patios. | Varies; some are portable, but larger models can be cumbersome. | Generally heavier; portable models available but usually require more space. |
| Price Range | $50 – $300; generally affordable. | $30 – $500; wide range depending on brand and features. | $100 – $1,500; can be expensive for high-end models. |
| Heat-Up Time | Heats up in minutes; ready to cook quickly. | Takes 20-30 minutes to reach cooking temperature. | Usually ready in 10-15 minutes. |
| Safety Features | Generally considered safe; no open flames. | Requires caution with hot coals; fire hazards. | Need to monitor gas leaks; safety shut-off features available. |
| Durability | Less durable; components may wear out over time. | Very durable; can last many years with proper care. | Durability varies; high-quality models can last a long time. |
What Key Features Should You Consider When Choosing an Outdoor Grill?
When selecting the best grills outdoor, there are several key features to consider to ensure you choose the right one for your needs.
- Fuel Type: The most common fuel types for outdoor grills are gas, charcoal, and electric. Gas grills offer convenience and temperature control, while charcoal grills provide that distinct smoky flavor. Electric grills are great for smaller spaces and ease of use but may lack the traditional grilling experience.
- Cooking Surface Area: The cooking surface area is crucial to determine how much food you can grill at once. Larger grills with expansive surfaces are ideal for entertaining or cooking for a family, while smaller grills are perfect for casual use or limited outdoor space.
- Build Quality: The durability of the grill is largely influenced by the materials used in its construction. Stainless steel grills tend to resist rust and corrosion, ensuring longevity, while porcelain-coated grills may offer better heat retention but can be less durable over time.
- Heat Output: Measured in BTUs (British Thermal Units), heat output indicates how quickly and efficiently a grill can cook food. Higher BTU ratings often mean faster cooking times, but the quality of heat distribution is equally important for even cooking.
- Portability: If you plan to take your grill on camping trips or tailgating, consider a portable model. Compact and lightweight grills are easier to transport and set up, making them a great choice for outdoor adventures.
- Additional Features: Many modern grills come with extra features such as side burners, rotisserie kits, and built-in thermometers. These features can enhance your grilling experience, allowing for more versatile cooking options and better temperature management.
- Cleaning and Maintenance: Ease of cleaning can significantly impact your grilling experience. Look for grills with removable grates, grease trays, and easy access to burners to simplify the cleaning process after cooking.
Why is Grilling Surface Area Important for Your Cooking Needs?
According to a study published by the National Barbecue Association, larger grilling surface areas allow for more even cooking and better heat distribution, which ensures that food is cooked thoroughly and uniformly. This is especially crucial for larger gatherings, where multiple items need to be cooked simultaneously without overcrowding the grill, which can lead to uneven cooking and longer cooking times.
The underlying mechanism behind the significance of grilling surface area involves heat retention and distribution. A larger surface area allows for better airflow and heat circulation, which helps maintain a consistent temperature across the grilling surface. When food is placed on a grill with inadequate surface area, it can lead to hot spots and cold spots, making it difficult to achieve the desired doneness. Furthermore, with more space, you can utilize different cooking techniques, such as direct and indirect grilling, enhancing the versatility of your cooking options.
How Do Safety Features Enhance Your Outdoor Grilling Experience?
Safety features significantly enhance your outdoor grilling experience by providing peace of mind and preventing accidents.
- Automatic Shut-Off: Many modern grills come equipped with automatic shut-off features that turn off the gas supply if a leak is detected or if the grill is left unattended for a certain period. This prevents potential fires and gas leaks, making grilling safer for everyone involved.
- Heat Shields: Heat shields are designed to protect the user from extreme temperatures and reduce flare-ups that can occur during grilling. They help distribute heat evenly and keep the exterior of the grill cooler, minimizing the risk of burns and injuries.
- Flame Tamers: Flame tamers are components placed above the burners to diffuse heat and prevent direct flames from reaching the food. By reducing flare-ups, they not only enhance cooking performance but also reduce the chances of uncontrolled flames, which can lead to burns or accidents.
- Built-in Thermometers: Grills with built-in thermometers allow users to monitor the internal temperature of their food without opening the lid. This feature helps prevent overcooking and reduces the need to handle hot surfaces frequently, enhancing safety during the grilling process.
- Non-slip Grates: Non-slip or textured grates provide better grip for food items, reducing the chances of slipping and falling into the fire. This feature can be particularly helpful when grilling delicate items that are prone to falling off traditional smooth grates.
- Safety Lock Mechanisms: Many grills come with safety lock mechanisms for handles and lids to prevent accidental openings while the grill is in use. This feature is especially important for families with children or pets around, as it minimizes the risk of burns or injuries from hot surfaces.
What Are the Most Trusted Brands for Outdoor Grills?
The most trusted brands for outdoor grills include:
- Weber: Known for its durable construction and user-friendly designs, Weber grills are a favorite among both amateur and seasoned grillers. Their range includes charcoal, gas, and electric options, providing versatility and high performance for outdoor cooking.
- Traeger: Traeger revolutionized outdoor grilling with its pellet grills, which combine the flavors of wood smoking with the convenience of digital temperature control. Their grills are designed for versatility, allowing users to smoke, grill, bake, and even braise, making them ideal for a variety of cooking styles.
- Char-Broil: Offering a wide range of affordable and quality grills, Char-Broil is well-known for its innovative features like infrared cooking technology. Their products cater to various grilling preferences, ensuring that budget-conscious consumers can still enjoy reliable performance.
- Broil King: Broil King stands out for its heavy-duty construction and powerful burners, delivering excellent heat retention and cooking performance. Their grills often feature rotisserie kits and a variety of cooking surfaces, making them perfect for both casual grilling and gourmet outdoor meals.
- Napoleon: Renowned for their high-end grills, Napoleon combines style with functionality, offering features like integrated smoke boxes and infrared burners. Their grills are designed for serious barbecue enthusiasts who appreciate quality craftsmanship and innovative cooking technology.
- Cuisinart: Known for its kitchen appliances, Cuisinart also produces a range of compact and portable outdoor grills. These grills are perfect for tailgating or small outdoor spaces and feature easy-to-use designs that cater to beginners and casual users alike.
Which Outdoor Grill Brands Are Renowned for Quality and Innovation?
The best outdoor grill brands recognized for their quality and innovation include:
- Weber: Known for its iconic kettle grills, Weber offers a range of gas, charcoal, and electric grills that emphasize durability and performance.
- Traeger: Pioneers of the pellet grill, Traeger combines convenience and flavor, allowing for precise temperature control and a wood-fired taste.
- Big Green Egg: This brand revolutionizes the kamado grill concept with its ceramic design, providing exceptional heat retention and versatility for grilling, smoking, and baking.
- Napoleon: Renowned for its high-end gas grills, Napoleon features innovative technology such as infrared burners and high-quality materials for superior cooking results.
- With a focus on performance and value, Broil King grills are designed with heavy-duty components and versatile cooking options, catering to both casual and serious grillers.
Weber grills are celebrated for their robust build and user-friendly features, making them a favorite among grilling enthusiasts. Their commitment to quality is evident in their warranties and customer service, ensuring long-lasting performance.
Traeger’s innovation lies in their use of wood pellets, which provide a unique flavor profile while simplifying the grilling process through digital temperature controls. This brand appeals to those who appreciate the taste of wood-smoked food without the hassle of traditional methods.
Big Green Egg stands out with its distinctive design and multi-functional capabilities. Its ability to maintain consistent temperatures allows users to perfect various cooking techniques, from searing to slow-roasting.
Napoleon grills are designed for those who seek luxury in outdoor cooking. Their advanced features, like infrared technology, allow for high-heat searing, while their sleek designs enhance outdoor aesthetics.
Broil King combines value and quality, making their grills popular among families and BBQ enthusiasts. Their grills are equipped with powerful burners and ample cooking space, catering to those who enjoy entertaining and large cookouts.
How Can You Prolong the Life of Your Outdoor Grill?
To prolong the life of your outdoor grill, consider the following maintenance and care practices:
- Regular Cleaning: Keeping your grill clean is essential for its longevity. After each use, scrape the grates and remove any food residue, as leftover grease and debris can lead to rust and corrosion over time.
- Proper Covering: Using a high-quality grill cover when the grill is not in use protects it from the elements. This prevents rain, snow, and debris from accumulating on the grill, which can cause damage and reduce its lifespan.
- Seasonal Maintenance: At the beginning and end of the grilling season, perform a thorough inspection and maintenance check. This includes checking for gas leaks, replacing worn-out parts, and ensuring all components are functioning properly.
- Temperature Control: Avoiding extreme temperature changes can help maintain the integrity of your grill. Always preheat your grill gradually and avoid leaving it in extreme heat or cold for extended periods.
- Fuel Management: For gas grills, regularly check and replace propane tanks or natural gas connections. Using the right fuel and ensuring proper connections can prevent leaks and promote efficient operation.
- Storage Position: When not in use, store your grill in an upright position and on a flat surface. This minimizes the risk of tipping over, which can cause physical damage to the grill and its components.
- Inspection for Rust: Regularly check for signs of rust on the grill. If rust is found, treat it promptly with a rust remover and repaint any affected areas to prevent further deterioration.
What Are the Essential Maintenance Tasks for Your Grill?
Essential maintenance tasks for your grill ensure it operates efficiently and prolongs its lifespan.
- Cleaning the Grates: Regularly scrub the grates with a grill brush after each use to remove food residue and grease. This prevents buildup that can affect the flavor of your food and ensures even heat distribution during cooking.
- Checking for Gas Leaks: For gas grills, periodically inspect the hoses and connections for any leaks using a soap solution. If you see bubbles forming, it indicates a leak that needs to be repaired to ensure safe operation.
- Emptying the Drip Tray: Frequently remove and clean the drip tray to prevent flare-ups and maintain hygiene. A full drip tray can lead to unpleasant odors and attract pests, compromising the grilling experience.
- Inspecting the Burners: Examine the burners for clogs and damage at least once a season. Clogged burners can lead to uneven heating, while damaged ones may pose a fire hazard, so it’s crucial to ensure they are clean and in good condition.
- Changing the Propane Tank: For propane grills, regularly check the fuel level and replace the tank when it’s low. Running out of propane mid-cook is inconvenient, and having a spare tank ensures uninterrupted grilling sessions.
- Covering the Grill: When not in use, cover your grill to shield it from the elements. A cover protects against rain, snow, and dust, which can cause rust and wear, extending the life of your grill.
- Seasoning the Grates: After cleaning, consider seasoning the grates with oil to create a non-stick surface. This not only prevents food from sticking but also helps protect the grates from corrosion over time.
- Performing a Deep Clean: At least once a year, conduct a thorough cleaning of the entire grill, including the exterior, interior, and all components. This deep clean helps maintain performance and can uncover any potential issues that need addressing.
What Common Mistakes Should You Avoid When Grilling Outdoors?
When grilling outdoors, avoiding common mistakes can enhance your cooking experience and ensure delicious results.
- Not Preheating the Grill: Failing to preheat your grill can lead to uneven cooking and sticking issues. Proper preheating allows the grill grates to reach the desired temperature, which helps achieve good sear marks and prevents food from clinging to the surface.
- Using the Wrong Fuel: Choosing the incorrect fuel type for your grill can affect the flavor and cooking efficiency. For example, using charcoal in a gas grill or vice versa can lead to poor heat retention and inconsistent cooking results.
- Overcrowding the Grill: Placing too much food on the grill at once can cause temperature drops and uneven cooking. It’s important to leave space between items to allow proper airflow and heat distribution, ensuring everything cooks evenly.
- Ignoring Food Temperature: Cooking food without checking its internal temperature can result in undercooked or overcooked dishes. Using a meat thermometer is essential for ensuring that meats reach safe cooking temperatures while maintaining juiciness and flavor.
- Opening the Lid Too Often: Frequently lifting the grill lid can cause heat loss and prolong cooking times. Keeping the lid closed helps maintain a consistent temperature, which is crucial for effective grilling and achieving those perfect grill marks.
- Not Cleaning the Grill: Neglecting to clean the grill grates before and after cooking can lead to flare-ups and unwanted flavors. Regular cleaning removes residue and helps maintain the grill’s performance, providing a better grilling experience.
- Using Too Much Marinade or Sauce: Excessive use of marinades or sauces can create flare-ups and uneven cooking. It’s best to apply sauces during the last few minutes of grilling to enhance flavor without overpowering the food or causing burning.
- Not Timing the Grill: Failing to monitor cooking times can result in overcooked or burnt food. Setting a timer and checking on the food regularly helps ensure that everything is cooked to perfection.
How Can Proper Temperature Control Improve Your Grilling Results?
Finally, time efficiency is a significant benefit of effective temperature management. By ensuring that the grill reaches and maintains the right temperatures, cooks can streamline their grilling process, leading to quicker meal preparation and happier guests.
What Techniques Can Elevate Your Outdoor Grilling?
Several techniques can enhance your outdoor grilling experience significantly.
- Preheating the Grill: Properly preheating your grill is essential for achieving perfect sear marks and ensuring even cooking. This process helps to reduce food sticking to the grate and allows for better flavor development.
- Using Two-Zone Cooking: This technique involves setting up your grill with a direct heat side and an indirect heat side, which allows for versatile cooking methods. You can sear meats over direct heat and then move them to the cooler side to finish cooking slowly, ensuring tenderness and juiciness.
- Marinating and Seasoning: Marinating your proteins or using dry rubs can infuse flavors deeply into the meat, enhancing taste and moisture. This technique not only improves flavor but also adds a layer of complexity to your grilled dishes.
- Utilizing a Thermometer: An instant-read thermometer ensures that your meats are cooked to the desired doneness without cutting into them. This technique helps prevent overcooking and ensures food safety, leading to perfectly grilled results every time.
- Experimenting with Wood Chips: Adding wood chips to your grill can introduce a smoky flavor that elevates your dishes. Different types of wood impart unique flavors, allowing you to customize the taste of your grilled items.
- Resting the Meat: Allowing grilled meats to rest before slicing helps redistribute juices, resulting in a more flavorful and moist final product. This technique emphasizes the importance of patience in achieving the best texture and flavor.
- Grilling Vegetables: Incorporating vegetables on the grill not only adds variety but also enhances flavors through caramelization. Grilling vegetables at high heat brings out their natural sweetness and creates appealing char marks.
- Using Grill Baskets: Grill baskets make it easier to cook smaller items like shrimp or sliced vegetables without losing them through the grates. They promote even cooking and allow for easier flipping and tossing of food.
How Can Using Accessories Enhance Flavor and Cooking Efficiency?
Using accessories can significantly enhance both flavor and cooking efficiency when grilling outdoors.
- Grill Thermometers: These tools allow for precise temperature readings, ensuring that meats are cooked to the perfect doneness. By monitoring the internal temperature, you can avoid overcooking or undercooking, leading to juicy and flavorful results.
- Grill Mats: Non-stick grill mats make it easier to cook delicate items like fish or vegetables without them falling through the grates. They also help in maintaining even heat distribution, which can enhance the overall flavor by preventing hotspots.
- Smoke Boxes: Adding a smoke box filled with wood chips to your grill introduces a rich, smoky flavor to your food. This accessory is particularly beneficial for meats, allowing you to infuse depth and complexity into your dishes with minimal effort.
- Grill Baskets: Perfect for holding smaller items or mixed vegetables, grill baskets keep food contained while allowing for even cooking. They also simplify the grilling process, reducing the risk of losing pieces through the grates and ensuring that every ingredient is evenly charred.
- Rotisserie Kits: These kits enable slow cooking of meats while they rotate over the heat, promoting even cooking and a deliciously crispy exterior. The constant rotation baste the meat in its own juices, enhancing flavor and tenderness.
- Heat Diffusers: By distributing heat evenly across the grill surface, heat diffusers prevent direct flames from charring food too quickly. This accessory is ideal for cooking larger cuts of meat that require longer cooking times without burning on the outside.
- Grill Brushes and Scrapers: Maintaining a clean grill surface not only ensures better flavor but also improves cooking efficiency. A clean grill prevents residue buildup, which can impart unwanted flavors to your food and reduce heat transfer.