The Ultimate Guide to Choosing the Best Insulation for Your Keezer Collar

By Bobby Rock •  Updated: 06/12/23 •  7 min read

Keezer collars are a popular addition to homebrewers’ setups, allowing them to convert chest freezers into temperature-controlled kegerators.

When it comes to creating an efficient and reliable keezer collar, choosing the right insulation is crucial.

In this article, we will explore different insulation options, factors to consider, and popular choices to help you determine the best insulation for your keezer collar.

Best Insulation for Your Keezer Collar

Best Insulation for Your Keezer Collar

As the craft beer scene continues to thrive, homebrewers are increasingly turning to keezers as a cost-effective and customizable solution for storing and dispensing their brews.

A keezer collar is a raised wooden frame that surrounds the chest freezer, providing additional space for faucets, shanks, and temperature control mechanisms.

Insulating the keezer collar is essential to maintain the desired temperature and prevent temperature fluctuations.

Types of Insulation

Foam Board Insulation

One of the most common insulation materials used in keezer collars is foam board insulation. It offers excellent insulation properties, ease of installation, and affordability. Foam board insulation comes in different types, such as extruded polystyrene (XPS) and expanded polystyrene (EPS). XPS is more rigid and durable, while EPS is lightweight and cost-effective. Both options provide good thermal insulation and moisture resistance, making them suitable for keezer collars.

To install foam board insulation, measure and cut the boards to fit the inner dimensions of the keezer collar frame. Use adhesive or insulation tape to secure the insulation panels in place, ensuring a snug fit. It’s also important to seal any gaps or joints with foam insulation sealant to minimize heat transfer and air leakage.

Spray Foam Insulation

Another option for keezer collar insulation is spray foam insulation. This type of insulation offers excellent thermal efficiency and air sealing properties. Spray foam insulation expands upon application, filling gaps and irregularities, creating a continuous insulation barrier. It adheres well to various surfaces and provides superior moisture resistance.

When using spray foam insulation, ensure proper ventilation and follow the manufacturer’s instructions. Take precautions to protect yourself and the surrounding area during application. It’s worth noting that spray foam insulation can be more expensive compared to foam board insulation and may require professional installation for optimal results.

Fiberglass Insulation

Fiberglass insulation is a widely used insulation material known for its affordability and thermal insulation properties. It consists of tiny glass fibers that trap air, providing insulation against heat transfer. Fiberglass insulation is available in batts or rolls and is relatively easy to install. However, it’s important to wear protective clothing, gloves, and a mask during installation to avoid irritation from the glass fibers.

When using fiberglass insulation in a keezer collar, ensure proper coverage and a tight fit to minimize heat loss. Be cautious not to compress the insulation, as it can reduce its effectiveness. Additionally, consider adding a vapor barrier to prevent condensation and moisture buildup.

Factors to Consider

When selecting the best insulation for your keezer collar, several factors come into play.

Thermal Efficiency

The primary purpose of insulation is to provide thermal efficiency by minimizing heat transfer. A well-insulated keezer collar helps maintain a consistent temperature and reduces energy consumption. Consider the insulation’s R-value, which measures its thermal resistance. Higher R-values indicate better insulation performance.

Foam board insulation, spray foam insulation, and fiberglass insulation can all provide satisfactory thermal efficiency. However, foam board insulation and spray foam insulation typically offer higher R-values compared to fiberglass insulation.

Moisture Resistance

Moisture can cause significant issues in a keezer collar, including mold growth, rust, and compromised insulation performance. Therefore, it’s crucial to choose insulation that provides adequate moisture resistance. Foam board insulation and spray foam insulation excel in this aspect, as they create a moisture barrier when properly installed.

Fiberglass insulation, on the other hand, may absorb moisture over time, leading to reduced effectiveness and potential mold growth. Adding a vapor barrier along with fiberglass insulation can help mitigate moisture-related concerns.

Cost and Availability

Cost and availability are essential factors to consider when choosing insulation for a keezer collar. Foam board insulation, particularly EPS foam, is usually more affordable compared to spray foam insulation. Fiberglass insulation falls within a similar price range as foam board insulation. However, the overall cost may vary depending on the size of your keezer collar and the insulation thickness required.

Availability can also play a role, especially if you have limited access to certain insulation materials. Consider local suppliers and check for availability before making a decision. Online retailers may offer a wider range of options if local availability is limited.

Popular Insulation Choices

Expanded Polystyrene (EPS) Foam

EPS foam insulation is a popular choice for keezer collars due to its affordability and insulation properties. It is lightweight, easy to handle, and offers good thermal resistance. EPS foam insulation comes in different thicknesses and can be cut to fit the keezer collar dimensions. Some notable brands in the market include Foamular and Owens Corning’s FOAMULAR.

Polyisocyanurate (Polyiso) Foam

Polyisocyanurate foam insulation, commonly referred to as polyiso foam, is known for its excellent thermal efficiency. It provides a high R-value per inch of thickness and offers good moisture resistance. Polyiso foam is compatible with keezer collars and can be a suitable option for those seeking maximum insulation performance. Look for reputable brands like Johns Manville and Hunter Panels for quality polyiso foam insulation.

Reflective Foil Insulation

Reflective foil insulation is a unique type of insulation that utilizes a reflective surface to reflect heat radiation. It consists of a layer of aluminum foil bonded to a backing material. Reflective foil insulation can be used in conjunction with other insulation materials to enhance thermal performance. It is particularly effective in reducing radiant heat transfer. Look for brands like Reflectix or RadiantGuard for reliable reflective foil insulation options.

Final Thoughts

Choosing the best insulation for your keezer collar is crucial for maintaining temperature control, energy efficiency, and overall performance. Foam board insulation, such as EPS foam or XPS foam, spray foam insulation, and fiberglass insulation are all viable options. Consider factors like thermal efficiency, moisture resistance, cost, and availability when making your decision.

Remember to measure and cut the insulation accurately, ensuring a proper fit within the keezer collar frame. Additionally, take appropriate precautions and follow installation guidelines for your chosen insulation material. By selecting the right insulation for your keezer collar, you can enjoy optimal temperature control for your homebrews.


  1. Can I use regular household insulation for my keezer collar?
    • It is recommended to use insulation materials specifically designed for insulation purposes, as they offer better thermal efficiency and moisture resistance. Regular household insulation may not provide the desired performance in a keezer collar.
  2. How thick should the insulation be in a keezer collar?
    • The insulation thickness depends on various factors, including the desired R-value, insulation material used, and the size of the keezer collar. Generally, thicker insulation provides better thermal insulation, but ensure it doesn’t interfere with the internal space needed for kegs and equipment.
  3. Is it necessary to add a vapor barrier with insulation in a keezer collar?
    • While not always necessary, adding a vapor barrier can help prevent moisture buildup and potential issues like mold growth. It is especially beneficial when using insulation materials like fiberglass.
  4. Can I combine different types of insulation in my keezer collar?
    • Yes, you can combine different types of insulation to enhance the overall performance of your keezer collar. For example, you can use foam board insulation as the primary insulation and add a layer of reflective foil insulation for additional radiant heat reflection.
  5. Should I hire a professional for installing insulation in my keezer collar?
    • While installation can be a DIY project, hiring a professional can ensure proper installation and maximize insulation performance. Professionals have the necessary experience and expertise to handle insulation materials safely and effectively.

Bobby Rock