MRCOOL 5th Gen DIY Mini-Split Builder & Sizing Guide
Use our MRCOOL DIY builder to size single-zone and multi-zone mini-split systems, match wall or ceiling cassette air handlers, choose QuickConnect pre-charged line sets, and pick the right 5th Gen multi-zone condenser. Built for DIY installers, med-to-pro HVAC users, and contractors. Nationwide shipping from Freedom HVAC Supply.
How the MRCOOL DIY Builder Works Open to read more
Select Single-Zone or Multi-Zone, then add rooms/zones. Choose each head type (wall mount or ceiling cassette), the BTU size, and your QuickConnect line-set length. The builder totals capacity and recommends the correct MRCOOL 5th Gen DIY multi-zone condenser (2–6 zones). Click “Add Full Bundle to Cart” to add the condenser, all heads, and matching line sets in one step.
Sizing Rules of Thumb Quick guide
- ≤175 sq ft → 6,000 BTU
- 150–350 sq ft → 9,000 BTU
- 350–500 sq ft → 12,000 BTU
- 500–750 sq ft → 18,000 BTU
- 750–1,000 sq ft → 24,000 BTU
- 1,000–1,500 sq ft → 36,000 BTU
Exposure, insulation, ceiling height, and room use (kitchen, sunroom, server) can change the final size. For exact loads, request a Manual J.
Manual-J Lite (Quick Load Estimator) Cooling/Heating BTU • Tons
Enter area, height, climate, and a few gains. This is a planning estimator—not for permits. For multi-zone or unusual homes, get a full Manual-J.
Why MRCOOL 5th Gen DIY? QuickConnect • R-454B Ready
5th Gen DIY systems pair pre-charged QuickConnect line sets with efficient multi-zone condensers and ENERGY STAR®-level wall/ceiling handlers. No vacuum pump required, safer R-454B readiness, and flexible zoning (2 to 6 zones) make installs faster and cleaner.
Nationwide Shipping, Warranty & Support We ship anywhere in the U.S.
Freedom HVAC Supply ships nationwide with fast fulfillment and tracking. MRCOOL offers limited warranties (see each product page). Our team can help with system matching, line-set selection, and accessory recommendations.
FAQs Top questions
Q: Can I mix wall mounts and ceiling cassettes?
A: Yes. The builder lets you mix head types per zone as long as total BTU and zone count match a compatible 5th Gen condenser.
Q: Do I need to pull a vacuum?
A: MRCOOL DIY QuickConnect line sets are pre-charged; no vacuum pump is needed when used as directed.
Q: What refrigerant?
A: Newer models support R-454B readiness/transition—check your exact condenser and handler specs before purchase.
Q: What if I’m between sizes?
A: Choose the next size up for high-gain rooms (sunrooms/kitchens), or consult us for a Manual J.