What size AC unit do I need? A complete guide to air conditioner sizing

Choosing the right air conditioner size ranks among the most critical decisions homeowners make when installing or replacing cooling systems. Get it wrong, and you’ll face years of discomfort, high energy bills and premature equipment failure. Despite its importance, AC sizing remains widely misunderstood. Many homeowners assume bigger is better, while others rely on rules of thumb that ignore their home’s unique characteristics. Understanding proper air conditioner sizing helps you invest wisely in equipment that delivers reliable comfort and efficiency.

Why AC size matters more than you think

Air conditioner size refers to cooling capacity measured in British Thermal Units (BTUs) per hour or tons (one ton equals 12,000 BTUs per hour). The term “size” has nothing to do with physical dimensions. Instead, it describes how much heat the system can remove from your home in a given time period.

Properly sized equipment runs in cycles lasting 15 to 20 minutes, efficiently cooling your home while removing humidity. Undersized units run constantly without adequately cooling your space. Oversized units create different but equally problematic issues. They cool spaces too quickly, cycling on and off frequently without running long enough to dehumidify air properly. This leaves your home feeling clammy and uncomfortable even though temperatures seem correct.

Oversized equipment also costs more to purchase and install, wastes energy through frequent startups, experiences accelerated wear from constant cycling and often fails years before properly sized systems. The efficiency ratings manufacturers advertise assume proper sizing and installation. An oversized high-efficiency system often performs worse than a correctly sized standard-efficiency model.

The problems with simple rules of thumb

Many contractors still use outdated rules suggesting one ton of cooling capacity per 500 to 600 square feet. While this provides a rough starting point, it ignores critical variables that dramatically affect cooling needs. Two 2,000-square-foot homes may require systems differing by a full ton or more based on construction quality, window placement, insulation levels and climate.

Another common mistake involves matching replacement system size to existing equipment. If your current AC is oversized (as many are), replacing it with the same capacity perpetuates the problem. Previous contractors may have oversized deliberately, believing bigger provides insurance against complaints, or they may have lacked proper training in load calculations.

Manual J load calculations: The professional standard

Professional HVAC contractors use Manual J load calculations to determine proper AC sizing. This comprehensive methodology, developed by the Air Conditioning Contractors of America (ACCA), considers dozens of factors affecting your home’s cooling needs.

Manual J calculations account for home square footage, ceiling height, window size and orientation, insulation levels in walls, attics and floors, air sealing quality, local climate data, number of occupants, internal heat sources like appliances and lighting, ductwork location and condition and thermostat settings. Contractors input these variables into specialised software that calculates your home’s heat gain on the hottest expected day of the year. This determines the minimum cooling capacity needed to maintain comfort during peak conditions.

Quality HVAC companies perform room-by-room calculations rather than whole-house estimates. This detailed approach ensures proper airflow distribution and identifies rooms requiring special attention. It also helps contractors design duct systems that deliver appropriate airflow to each space.

Factors that increase cooling needs

Several characteristics increase your home’s cooling requirements:

Poor insulation: Inadequate attic, wall or floor insulation allows heat to penetrate your home more easily. Older homes built before modern energy codes typically need more cooling capacity than newer, well-insulated construction.

Large windows, especially south and west facing: Windows account for significant heat gain. Homes with many large windows or extensive south and west exposure absorb substantial solar heat. High-quality windows with low-E coatings reduce this effect but don’t eliminate it.

Cathedral or vaulted ceilings: High ceilings increase the volume of air requiring cooling. They also create stratification where hot air accumulates above living spaces, making systems work harder to maintain comfort.

Open floor plans: While open layouts facilitate airflow, they create large spaces requiring substantial cooling capacity. Combined living, dining and kitchen areas in modern homes often challenge smaller systems.

Hot climates: Homes in regions with sustained temperatures exceeding 95 degrees need more capacity than those in moderate climates. The greater the difference between indoor and outdoor temperatures, the more cooling capacity required.

Factors that reduce cooling needs

Other characteristics allow smaller, more efficient systems:

Excellent insulation and air sealing: Well-insulated, tightly sealed homes retain cool air effectively. Modern construction meeting current energy codes requires less cooling capacity than older homes of similar size.

Quality windows with proper shading: Energy-efficient windows, awnings, shade trees and window treatments dramatically reduce solar heat gain. Homes with minimal west-facing glass or extensive shading need less cooling capacity.

Efficient lighting and appliances: LED lighting and Energy Star appliances generate less waste heat than older technology. While the difference seems minor, it accumulates across multiple fixtures and devices.

Moderate occupancy: Smaller households generate less heat than larger families. People, pets and activities all contribute to internal heat gain.

Typical residential AC sizes

For reference, residential air conditioners typically range from 1.5 to 5 tons. Here are general guidelines based on square footage, assuming average construction quality and conditions:

600-1,000 sq ft: 1.5-2 tons
1,000-1,500 sq ft: 2-2.5 tons
1,500-2,000 sq ft: 2.5-3 tons
2,000-2,500 sq ft: 3-3.5 tons
2,500-3,000 sq ft: 3.5-4 tons

Remember these are rough estimates only. Your specific home may fall outside these ranges based on the factors discussed above. Never select equipment size without professional load calculations.

The installation quality factor

Even correctly sized equipment performs poorly with substandard installation. Ductwork must be properly sized, sealed and insulated. Refrigerant charge must be exact. Airflow across evaporator coils requires precise adjustment. These technical details separate quality contractors from those simply swapping equipment.

When you invest in professional air conditioning installation, you’re paying for expertise that ensures your system operates at its rated efficiency. The cheapest installation quote often delivers the most expensive long-term results through wasted energy and premature equipment replacement.

Questions to ask HVAC contractors

When obtaining quotes for new AC systems, ask these questions to identify contractors who size equipment properly:

Will you perform a manual J load calculation for my home?
What factors about my home affect the recommended system size?
Why is this size appropriate for my specific situation?
What efficiency rating do you recommend and why?
How will you ensure proper refrigerant charge and airflow?

Quality contractors welcome these questions and explain their sizing methodology clearly. Those who estimate size based solely on square footage or existing equipment lack the professionalism your investment deserves.

Beyond cooling capacity: efficiency considerations

Once you determine proper cooling capacity, consider efficiency ratings. Seasonal Energy Efficiency Ratio (SEER) measures cooling efficiency. Higher SEER ratings indicate more efficient operation. Modern systems range from 14 SEER (minimum legal efficiency) to 25+ SEER for premium equipment.

While high-efficiency systems cost more upfront, they deliver lower operating costs throughout their lifespan. The ideal balance between initial investment and ongoing savings depends on your climate, usage patterns and how long you plan to own your home. Contractors should help you understand payback periods for efficiency upgrades.

Making the right investment

Determining what size AC unit you need requires professional expertise and detailed analysis of your home’s characteristics. Proper sizing delivers comfortable temperatures, appropriate humidity control, reasonable operating costs and equipment longevity matching manufacturer expectations. Oversizing or undersizing compromises all these benefits while wasting money on either inadequate comfort or excessive equipment capacity.

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12 factors to consider when designing a custom closet

Designing a custom closet is an opportunity to create storage that truly works for your lifestyle. Instead of forcing your belongings into a basic layout, a custom closet allows you to plan every detail, from how you hang clothes to how accessories are stored and displayed.

Homeowners often look to experienced craftsmen like Riverside Millwork Group for inspiration when exploring high-quality, custom-built storage solutions that combine function with thoughtful design. Before you finalise your design, here are the key factors to consider when building a closet that’s both functional and beautifully organised.

1. Hanging space configuration

One of the first decisions is how much hanging space you need. Options include single-hang sections for long garments, double-hang rods for shirts and trousers and mixed configurations to maximise vertical space.

2. Shelving style and placement

Shelving is essential for folded clothing, handbags and storage bins. Adjustable shelves allow flexibility, while fixed shelves provide a clean, built-in look. You can choose open shelving for visibility or enclosed shelving for a streamlined appearance.

3. Drawer options

Built-in drawers are perfect for organising smaller items. Consider shallow drawers for accessories, deeper drawers for clothing and soft-close hardware for a premium feel. Drawer inserts can further organise socks, jewellery or undergarments.

4. Shoe storage solutions

Shoes deserve dedicated storage. Options include angled shelves, cubbies, pull-out shoe racks or floor-to-ceiling shoe walls. The size of your collection and types of shoes you own will determine the best setup.

5. Accessory organisation

Custom closets offer a variety of accessory storage options, such as pull-out belt racks, tie organisers, jewellery trays, watch drawers and handbag shelves. These features keep items visible, protected and easy to access.

6. Lighting features

Lighting plays a big role in functionality. Built-in LED strip lighting, motion-sensor lights and illuminated shelves improve visibility and elevate the overall design. Proper lighting ensures nothing gets lost in dark corners.

7. Use of vertical space

Maximising height is key in custom design. Upper cabinets, overhead shelves and tall storage units provide space for seasonal clothing, luggage and less-used items while keeping everyday essentials within reach.

8. Finish and material choices

Closet finishes help define the look and feel of the space. Options range from clean whites and wood tones to textured laminates and accent panels. Durable materials ensure your closet stands up to daily use.

9. Layout and flow

A good layout makes your closet easy to navigate. Walk-in closets benefit from clear pathways and balanced storage zones, while reach-in closets require careful planning to avoid overcrowding.

10. Mirrors and seating

Full-length mirrors are both practical and space-enhancing. Seating options, such as built-in benches or ottomans, add convenience for dressing and shoe changes while creating a boutique-style feel.

11. Speciality storage features

Depending on your needs, you may want speciality storage like pull-out hampers, valet rods for outfit planning, luggage compartments or dedicated space for athletic gear or seasonal wear.

12. Flexibility for the future

Your closet should grow with you. Adjustable components and modular designs allow easy changes as your wardrobe or lifestyle evolves, ensuring long-term functionality.

A closet designed around you

A custom closet is a lifestyle improvement. By considering how you use your space and selecting the right features, you can create a closet that feels organised, intuitive and effortless to maintain. With thoughtful planning and the right options, your custom closet becomes a space that supports your routine and enhances your home every day.

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Expert tips for window repair: a DIY guide for homeowners

Windows play a bigger role in your home than you may think. They affect energy efficiency, comfort, noise control and even how polished your home looks from the outside. Homeowners often turn to experienced professionals like George Kent Home Improvements for guidance on maintaining and repairing their windows, but many common issues can be handled safely with the right DIY approach.

Over time, wear and tear can lead to draughts, condensation, sticking frames or cracked glass. The good news is that not every problem requires a full window replacement. With a little bit of know-how, you can tackle many window repairs yourself and extend the life of your windows.

Start by identifying the real problem

Before jumping into repairs, take time to identify what’s causing the issue. Common window problems include drafts, condensation between panes, difficulty opening or closing, cracked glass and damaged frames. Knowing whether the issue is cosmetic, mechanical or structural helps you choose the right solution and avoid unnecessary work.

Seal drafts to improve energy efficiency

Draughty windows are one of the most common (and fixable) problems. If you feel cold air around the frame, worn weatherstripping or cracked caulking is often the cause. Remove old caulking and apply a high-quality exterior-grade sealant. Replace damaged weatherstripping on movable windows to close gaps and prevent air leaks. This simple upgrade can noticeably improve comfort and reduce heating and cooling loss.

Fix sticking or hard-to-open windows

Windows that stick or refuse to stay open are frustrating but usually easy to repair. Dirt, debris, paint buildup or moisture-related swelling can all affect window operation. Clean tracks thoroughly and remove any paint buildup. Light sanding along painted edges can help wood windows move freely again. Apply a silicone-based lubricant to tracks or pulleys for smoother operation.

Repair or replace window screens

Torn or loose window screens don’t require a full replacement. Screen repair kits are affordable and widely available. Remove the screen frame, replace the damaged mesh and secure it using spline and a roller tool. This quick DIY fix improves airflow while keeping insects out.

Address condensation between panes

Fog or moisture trapped between double- or triple-pane windows usually indicates a failed seal. Unfortunately, this isn’t a DIY fix for the glass unit itself. You can slow further damage by sealing around the window frame and managing indoor humidity, but persistent condensation often means professional repair or replacement is needed.

Repair minor wood rot early

Wood-framed windows are especially vulnerable to moisture damage. If caught early, rot can often be repaired. Remove damaged wood, apply a wood hardener and fill the area with exterior-grade wood filler. Once cured, sand smooth and repaint to seal the surface and prevent further decay.

Handle cracked glass with care

Small cracks in single-pane windows can sometimes be stabilised with glass repair resin. Always wear gloves and eye protection when working with glass. For larger cracks or shattered panes, replacing the glass is safer. If the window is large or difficult to access, it’s best to call a professional.

Check hardware and locks

Loose locks, worn hinges and broken latches can compromise both security and usability. Tighten screws, replace worn hardware and ensure all locks function properly. These small fixes improve safety and extend the life of your windows.

Use the right tools and materials

Successful window repair depends on using exterior-rated materials and proper tools. A caulking gun, putty knife, sanding block, utility knife and safety gear will cover most DIY repairs.

Know when to call a professional

DIY repairs are ideal for minor issues, but extensive rot, structural damage or failed insulated glass units should be handled by professionals to ensure safety and long-term performance.

Small repairs, big results

Window repair doesn’t have to be overwhelming. With expert tips and a careful approach, many common window issues can be resolved with simple DIY solutions. Regular maintenance improves comfort, efficiency and the lifespan of your windows, helping your home perform better year after year.

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MERV 8 vs 11 vs 13: Which air filter rating is right for your home?

There’s nothing quite like the peace of mind that comes with knowing the air inside your home is clean, safe and free of allergens. For many homeowners, navigating the confusing world of HVAC maintenance is a chore, but Filter King aims to change that narrative with American-made quality and a hassle-free subscription model.

If you’re tired of forgetting to change your filters or struggling to find the right size at the hardware store, this may be the solution you’ve been waiting for.

In this review, we dive deep into the specific MERV ratings offered by Filter King custom HVAC filters to help you decide which level of protection is right for your household. From pet dander to microscopic viruses, understanding these ratings is the key to improving your indoor air quality without overspending. We also test their claims of superior customer service and custom sizing.

Best purchase I’ve made all year for my home maintenance routine!

What is Filter King?

Filter King is a direct-to-consumer service specialising in AC and furnace replacement filters. Unlike generic options found in big-box stores, Filter King manufactures their filters in the USA and offers an impressive range of standard and custom sizes.

Their primary goal is to simplify home maintenance through a subscription model that allows you to pause, change or cancel deliveries at any time, ensuring you never run your HVAC system with a dirty filter again.

This service is designed for homeowners, HVAC professionals and allergy sufferers who require specific filtration levels. Whether you need a standard MERV 8 for dust protection or a high-efficiency MERV 13 for asthma and virus control, Filter King provides a tailored experience. Their unique selling point is the combination of premium build quality, using industrial-grade backings and the convenience of having them delivered right to your door.

Key insight: The standout value proposition here is the custom sizing. While big-box stores only stock standard dimensions, Filter King manufactures to the exact eighth of an inch, eliminating the air gaps that compromise filtration efficiency.

Which MERV rating fits?

Understanding the trade-offs between airflow and filtration is critical for choosing the right MERV (Minimum Efficiency Reporting Value). Here’s how the three main options stack up in real-world performance.

MERV 8 (The Standard Protector): This filter is the workhorse for most residential homes. It captures dust, lint and pollen without restricting airflow, making it ideal for older HVAC systems that struggle with high resistance. It provides basic protection for your furnace components but won’t capture finer particles like pet dander or smoke.

MERV 11 (The Pet Owner’s Choice): If you have furry friends, the MERV 11 is the “protein” of the line-up. It features a denser weave that traps pet dander, fine dust and auto emissions. The trade-off is a slight increase in airflow resistance, so it’s best suited for modern HVAC systems that can handle the extra drag.

MERV 13 (The Ultimate Shield): This hospital-grade option is the “superfood” for your home; blocking bacteria, virus carriers and smoke. However, its high density significantly restricts airflow, which can strain older furnaces or AC units. It’s highly recommended for asthma sufferers or those living in areas prone to wildfires – provided your system is compatible.

Pro tip: Don’t automatically buy the highest MERV rating. MERV 8 is sufficient for standard dust control and airflow. Only upgrade to MERV 11 for pets, or MERV 13 if you have specific medical needs such as asthma.

5 Interesting quality features

1. Frame quality and crispness

Filter King filters feature a sturdy construction that doesn’t bend or collapse under pressure. Users report a noticeable difference in air crispness, lacking the dusty smell often associated with cheaper fibreglass filters.

2. Filtration media

Filter King uses synthetic media, which is superior to fibreglass, capturing more particulates per pass without restricting airflow to dangerous levels. The pleated design increases surface area, acting like high dietary fibre to scrub your air clean.

3. Made in the USA

There are no cheap imports here; the combination of high-strength beverage board frames and metal mesh backing ensures the filter stays in place. The transparency regarding their manufacturing process complies with FTC rules.

4. Value for money

When compared to big-box retailers like Lowe’s or Home Depot, Filter King shines in the value department. By cutting out the middleman, they offer premium protection at a lower cost per unit, especially when bought in bulk. Free shipping on all orders saves significant money over time.

5. Transparency

The pricing is transparent, the subscription is easy to cancel and the product does exactly what it claims. There’s no marketing “sugar-coating” – if you order the wrong size, they fix it.

Filter King vs Big Box?

Many homeowners default to buying filters at large hardware chains like Home Depot or Lowe’s. However, when you compare Filter King against these retail giants, the differences in customisation and service become apparent.

The table below highlights the cost and convenience differences between Filter King and standard retail stores.

Feature	Filter King	Big Box Retailers
Price per serving (Filter)	Lower (Direct-to-consumer)	Higher (Retail markups)
Custom sizes	Yes (Made to order)	No (Standard sizes only)
Convenience	Auto-delivery after first order	Manual store trips

While big box stores offer immediate gratification if you’re standing in the aisle, they often lack specific odd sizes and charge a premium for higher MERV ratings. Filter King wins on long-term value and the ability to fit unique HVAC systems that standard retailers simply can’t service.

If I didn’t save 8-10 dollars over [Lowe’s] and [Home Depot], I would be buying them there.” – Gary C., Verified buyer

Customer ratings & reviews

Customer	Review
Sally S.	Great customer service. Original pkg damaged in shipping; replaced w/in 30 minutes of texting customer service; replacements arrived undamaged and fit well. Happy to deal with ‘Made in America’ and Filter King.
Nels	Easy to order, works just as it should. The filter was exactly as ordered, a perfect fit for my old system that isn’t a standard size. This is where I will be getting filters from now on, definitely.
Gary C.	Another satisfied repeat customer. I have been buying my filters from Filter King for over 10 years and never been disappointed. If I didn’t save 8-10 dollars over L and H D, I would be buying them there.
Melissa K.	Amazing Service. We needed filters, and hubby got the size wrong after I had placed the order. I texted you once about shipping, answered quickly and then, after my order, explained the mistake and you fixed it.

5 Frequently asked questions

1. How often should I change my furnace filter?

Most homeowners should replace their furnace filter every 90 days. However, if you have pets, smoke indoors or run your HVAC system frequently, every 60 days is recommended. For severe allergies or asthma, a 30-day replacement cycle ensures the cleanest air.

2. Will a dirty air filter affect my AC performance?

Yes, a dirty air filter restricts airflow, forcing your HVAC system to work much harder to pull air through. This leads to poor cooling or heating performance and significantly increased energy bills. It can even cause the system to freeze up or overheat.

3. What happens if I install the air filter backwards?

Installing a filter backward can reduce airflow and strain your HVAC system. The filter is designed with a porous side to allow air in and a denser mesh side to capture particles. Reversed filters resist airflow, which drives up energy costs and can damage the blower motor.

4. Can I run my furnace without a filter?

Technically, yes, but it’s strongly discouraged. The filter protects the internal components of your HVAC system from dust and debris. Without it, particles build up on the coils and motor, reducing efficiency and potentially causing permanent damage.

5. Is this good for allergies?

Yes, specifically if you choose the MERV 11 or MERV 13 options. The MERV 13 filter is capable of trapping bacteria, virus carriers and microscopic allergens that standard filters miss, making it an excellent tool for reducing indoor allergy symptoms.

Important: Never operate your HVAC system without a filter, not even temporarily. Dust accumulation on internal coils happens quickly, leading to reduced efficiency, system overheating and expensive professional cleaning bills that far exceed the cost of a filter.

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