HVAC & mini-split guides

Planning articles for DIYers sizing ductless mini-splits — bedrooms, RVs, tiny homes, backyard studios, and seasonal cottages. Pair each guide with the free BTU calculator.

Sizing basics

BTU Per Square Foot Explained — Room Sizing Basics

How the 20–30 BTU per sq ft rule works, when to go higher or lower, and how insulation, climate, and sun exposure change your load.

9 min read

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Sizing basics

How Many BTU for a Bedroom? — AC & Mini-Split Sizing

BTU sizing for 10×10, 12×12, and master bedrooms. Why minimum unit sizes matter and when to choose a mini-split over a window AC.

8 min read

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Sizing basics

Common Mini-Split Sizing Mistakes — And How to Avoid Them

Oversizing, copying old unit BTU, ignoring sun and insulation, and sizing multi-room spaces on one head. Fix these before you buy.

8 min read

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Sizing basics

How to Size AC for an Open Floor Plan — Single-Zone Tips

Cooling kitchen-living combos and great rooms with one mini-split head. How to measure, when one zone works, and when to add a second head.

9 min read

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Sizing basics

Window AC BTU Sizing — Room Dimensions & Plug-In Units

How to size window and portable AC units by BTU, minimum unit sizes, and when a mini-split is worth the upgrade.

8 min read

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Mini-split guides

Mini-Split vs Window AC — Which Is Right for You?

Compare cost, efficiency, noise, install difficulty, and sizing for ductless mini-splits and window air conditioners in bedrooms, sheds, and small spaces.

9 min read

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Mini-split guides

Single-Zone vs Multi-Zone Mini-Split — How to Choose

One outdoor unit with one head vs multiple indoor heads. When open floor plans work with a single zone and when you need separate rooms.

8 min read

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Mini-split guides

SEER Ratings Explained — Mini-Split Efficiency Guide

What SEER and SEER2 mean on ductless heat pumps, how higher ratings save money, and what to look for when comparing models.

8 min read

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Mini-split guides

Heat Pump vs Air Conditioner — What Homeowners Should Know

Cooling-only AC vs heat pumps that heat and cool. Efficiency labels, climate limits, and sizing overlap with mini-splits.

9 min read

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Mini-split guides

Portable AC vs Window AC — Noise, BTU & Efficiency

Compare portable roll-around units to window AC for bedrooms, rentals, and HOA restrictions. Dual-hose vs single-hose efficiency.

8 min read

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Tiny homes

Mini-Split Sizing for Tiny Homes — BTU & One-Head Plans

Size ductless AC and heat pumps for 200–400 sq ft tiny houses. Loft ceilings, galley kitchens, and THOW air leakage factors.

9 min read

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Tiny homes

Insulating a Tiny Home for HVAC — Before You Size AC

Spray foam, rigid board, and air sealing for tiny houses. Why insulation cuts BTU load and prevents condensation in small envelopes.

9 min read

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RV & mobile

What Size Mini-Split for an RV? — BTU by Length & Layout

Mini-split BTU sizing for travel trailers, fifth-wheels, and skoolies. Thin walls, windows, and full-time hot-climate living.

8 min read

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RV & mobile

RV Mini-Split Installation Options — Mounting & Power

Condenser on hitch rack, bumper mount, or roof bracket. Line sets, vibration, and shore power for DIY RV ductless installs.

10 min read

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Cottages & cabins

She-Shed Heating and Cooling — Mini-Split Sizing Guide

Heat and cool a backyard she-shed, art studio, or office shed. Insulation steps, typical 10×12 to 12×20 BTU ranges, and electrical basics.

8 min read

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Cottages & cabins

Cottage Mini-Split Guide — Sizing Cabins & Seasonal Homes

Ductless sizing for lake cabins, seasonal cottages, and vacation homes. Insulation honesty, winter heat pump limits, and multi-room options.

9 min read

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DIY install

DIY Mini-Split Installation Basics — Planning Checklist

Pre-charged kits, line sets, wall mounts, vacuum, and electrical for homeowner-installed ductless systems. What DIY can cover and when to call a pro.

10 min read

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DIY install

Mini-Split for Garage Workshop — Cooling & Heating DIY Spaces

Size ductless AC for garages and workshops. Insulation, door leakage, equipment heat, and 220V planning for maker spaces.

9 min read

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DIY install

DIY Mini-Split Project Roadmap — Size, Wire, Mount & Start Up

Plan a ductless mini-split project from BTU sizing and zone selection through electrical work, placement, mounting, startup, and professional handoff.

12 min read

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DIY install

Mini-Split Electrical Requirements — Breaker, Wire & Disconnect

DIY electrical planning for ductless mini-splits: 110V vs 220V, breaker size, wire gauge, outdoor disconnect, and when to hire an electrician.

9 min read

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DIY install

Mini-Split Indoor and Outdoor Placement — Clearances That Work

Where to mount the indoor head and outdoor condenser: airflow, noise, line-set length, sun, snow, and drainage for DIY ductless installs.

9 min read

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DIY install

Pre-Charged DIY Mini-Split Kits Explained — When They Work

How pre-charged ductless kits differ from traditional vacuum-and-charge installs, line-length limits, flaring tips, and when DIY stops being a good idea.

9 min read

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DIY install

When to Hire a Mini-Split Installer — DIY vs Pro

Honest guide to DIY vs professional ductless install: multi-zone, long line sets, electrical, permits, and warranties. Still size BTU yourself with free calculators.

9 min read

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DIY install

How to Install a Window AC Safely — Support, Seal & Power

DIY window air conditioner install: sash support, brackets, sealing gaps, correct outlet circuit, and tipping hazards. Size BTU before you buy.

9 min read

Window AC calculator →