Ductless mini-splits are the preferred choice for workshop climate control, providing efficient year-round heating and cooling without ductwork. This calculator accounts for workshop-specific factors like high ceilings, insulation quality, and heat-generating equipment to recommend the right system size for your space.
24,000 BTU, 20 SEER, 230V. DIY install with pre-charged refrigerant. Alexa and Google compatible.
View on Amazon18,000 BTU, 20 SEER, 230V. No HVAC license required. Pre-charged 25 ft line set included.
View on Amazon24,000 BTU, 22 SEER, 230V. Hyper heat technology works down to -22F. WiFi ready.
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Enter your workshop specifications to get a personalized BTU recommendation. Workshops have higher heat loads than residential spaces due to equipment and insulation differences.
Based on your workshop specifications, you need an 18,000 BTU mini-split system.
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Our mini-split sizing calculator uses a workshop-specific formula that accounts for factors often overlooked by standard residential HVAC calculators.
We use 25 BTU per square foot (vs. 20 for residential) to account for workshop thermal loads and intermittent use patterns that require faster temperature recovery.
For each foot above the standard 8-foot ceiling, we add 10% to account for increased air volume. A 12-foot ceiling has 50% more air to condition.
Multipliers range from 0.9 for excellent insulation to 1.3 for uninsulated spaces, reflecting the dramatic impact insulation has on heating and cooling loads.
Heavy sun exposure adds 15% to cooling requirements, while shaded or north-facing spaces may need 10% less capacity.
Each major heat source (welder, plasma cutter, etc.) adds approximately 2,000 BTU to the total load.
DIY mini-split systems like MRCOOL are designed for homeowner installation and come with pre-charged line sets. No HVAC license is required in most areas. However, you will need basic electrical skills for the 240V connection and the ability to mount the indoor and outdoor units. The installation typically takes 4-8 hours for someone with moderate DIY experience. You will need a hole saw, level, drill, and basic hand tools. The most challenging aspects are running the electrical circuit and properly sealing the wall penetration where the refrigerant lines pass through.
Yes, mini-splits are heat pumps that provide both cooling and heating. Most models work effectively down to 5F, and hyper-heat models can operate down to -22F. They are highly efficient for heating, typically delivering 3 BTU of heat for every 1 BTU of electricity consumed. This makes them roughly 3 times more efficient than electric resistance heaters. However, heat pump capacity decreases as outdoor temperatures drop, so if you live in an extremely cold climate, consider sizing up one capacity level or supplementing with a backup heat source for the coldest days.
Single-zone systems have one outdoor unit connected to one indoor unit, perfect for heating and cooling a single open space. Multi-zone systems connect one outdoor unit to 2-5 indoor units, allowing independent temperature control in different rooms or areas. For most open-plan workshops, a single-zone system is the best choice due to lower cost and simpler installation. Multi-zone makes sense if you have separate spaces like an office, paint booth, or storage room that need different temperatures. Note that multi-zone outdoor units are significantly larger and more expensive than their single-zone counterparts.
For most workshops, the cooling load is the primary sizing factor because heat from equipment, sun exposure, and poor insulation creates a significant cooling demand. However, if you live in a cold climate and will rely on the mini-split for heating, you may need to size up. Heat pump capacity decreases as outdoor temperature drops. A unit rated at 24,000 BTU might only deliver 18,000 BTU when it is 17F outside. Our calculator uses cooling-based sizing, but if winter heating is your priority, consider the next size up or a hyper-heat model that maintains capacity at low temperatures.
SEER (Seasonal Energy Efficiency Ratio) measures cooling efficiency. The minimum allowed is currently 14 SEER in most regions. For workshop use, 17-20 SEER provides excellent efficiency without excessive upfront cost. Higher SEER ratings (20-25) cost more but provide lower operating costs. The payback period depends on how often you use your workshop and your local electricity rates. If you work in your shop daily and electricity costs are high, investing in a 20+ SEER unit makes sense. For occasional weekend use, a 17-18 SEER unit offers the best value.
Mini-splits of 12,000 BTU and under often run on 120V/15A circuits, making them easy to add to existing electrical systems. Units of 18,000 BTU and larger typically require dedicated 240V circuits rated for 20-30 amps. The outdoor unit contains the electrical connection, so you will need to run a circuit from your panel to the outdoor unit location. Most installations require a disconnect box mounted within sight of the outdoor unit. Before purchasing, check your electrical panel for available capacity and consult local codes. Some jurisdictions require permits for new 240V circuits.
Planning your complete workshop climate and electrical system? These calculators help you size related equipment and plan your installation.