If you’re considering upgrading your windows, you’ve probably come across the term double glazed unit. But what exactly is it, how does it work, and why is it essential for modern homes?
A double glazed unit (DGU) is a sealed window unit made of two panes of glass with an insulating gap between them. This design significantly improves energy efficiency, noise reduction, and home security compared to single glazing.
In this guide, we’ll break down everything you need to know about double glazed units, including their benefits, how they work, and why they’re a must-have for UK homeowners.
1. What Is a Double Glazed Unit?
A double glazed unit consists of:
- Two glass panes – These can be standard, toughened, laminated, or Low-E glass.
- An air or gas-filled gap – Usually filled with argon, krypton, or xenon gas for improved insulation.
- A spacer bar – Separates the panes and maintains an airtight seal.
- A desiccant material – Absorbs moisture to prevent condensation inside the unit.
- A sealed frame – Keeps the unit airtight and prevents leaks.
This structure enhances insulation by reducing heat loss, making it a popular choice for energy-efficient windows.
2. How Does a Double Glazed Unit Work?
The key to a double glazed unit’s performance is the insulating layer between the two glass panes. Here’s how it works:
- Thermal Insulation:
- The air or gas layer between the panes slows down heat transfer.
- Warm air inside your home stays in, while cold air from outside is blocked.
- This reduces heat loss in winter and prevents overheating in summer.
- Noise Reduction:
- The double layers of glass act as a barrier to sound waves, making your home quieter.
- Ideal for homes near busy roads, airports, or noisy neighbourhoods.
- Condensation Prevention:
- The desiccant inside the spacer bar absorbs moisture.
- A properly sealed unit prevents condensation from forming between the panes.
- Enhanced Security:
- Double glazing is stronger than single glazing, making it harder for intruders to break in.
- Toughened or laminated glass options add extra protection.
3. Why You Need a Double Glazed Unit
1. Energy Efficiency & Lower Bills
- Reduces heat loss by up to 50%, lowering your energy bills.
- Helps homes achieve better EPC ratings, which can increase property value.
- Can cut heating costs by £100-£300 per year (Energy Saving Trust).
2. Improved Comfort
- Maintains a stable indoor temperature, preventing cold spots near windows.
- Helps keep your home cooler in summer and warmer in winter.
3. Noise Reduction
- Double glazing can reduce outside noise by up to 70%.
- Perfect for homes in urban areas or near main roads.
4. Increased Security
- Toughened or laminated glass makes break-ins more difficult.
- Multi-point locking systems enhance security further.
5. Reduced Condensation
- Prevents moisture build-up between panes, reducing mould and damp issues.
- Helps maintain a clear view with no foggy windows.
4. Types of Double Glazed Units
1. Standard Double Glazing
- Affordable and offers good insulation.
- Suitable for most UK homes.
2. Low-E (Low Emissivity) Glass
- Coated to reflect heat back inside.
- Reduces energy loss while letting natural light in.
3. Toughened or Laminated Glass
- Stronger and more secure than standard glass.
- Ideal for ground-floor windows and doors.
4. Acoustic Glass
- Designed to block out noise pollution.
- Perfect for properties near airports or busy roads.
5. Solar Control Glass
- Helps reduce heat gain from sunlight.
- Ideal for homes with large south-facing windows.
5. Double Glazed Unit vs. Triple Glazed Unit
Many homeowners wonder whether triple glazing is worth the extra cost. Here’s a quick comparison:
- Double Glazed Unit:
- More affordable than triple glazing.
- Provides good insulation and noise reduction.
- Ideal for most UK homes.
- Triple Glazed Unit:
- Offers even better insulation but costs more.
- Helps in extreme cold climates.
- Adds extra weight to window frames.
For most UK properties, double glazing provides the best balance of cost and performance.
6. How to Maintain a Double Glazed Unit
To extend the lifespan of your double glazed unit, follow these simple maintenance tips:
- Clean the glass regularly with a mild detergent and soft cloth.
- Check for condensation between panes – this may indicate a broken seal.
- Inspect window seals to ensure they remain airtight.
- Lubricate hinges and locks to keep them functioning smoothly.
Proper maintenance ensures your windows last 20-30 years or more.
7. How to Replace a Faulty Double Glazed Unit
If your double glazed unit is misted, cracked, or underperforming, you don’t always need a full window replacement. Replacing just the glass unit is often a cheaper and quicker solution.
At Cove Glass, we provide expert double glazed unit replacements for all window types.
🔗 Get a quote today: Cove Glass Double Glazing
📞 Call us: 01252 318787
📧 Email us: sales@coveglass.co.uk
Frequently Asked Questions (FAQs)
Q1: How long does a double glazed unit last?
A1: A well-maintained double glazed unit typically lasts 20-30 years.
Q2: Can you replace just one pane of a double glazed unit?
A2: No, both panes are sealed together, so the entire unit must be replaced.
Q3: Does double glazing add value to a home?
A3: Yes, energy-efficient windows can increase property value and make a home more attractive to buyers.