⚖️ Sizing Isn’t Guesswork — It’s Everything
If you’re putting PTACs into hotel rooms, senior living suites, dorms, or offices, choosing the right BTU size is non-negotiable. A unit that’s too small won’t cool the space, and one that’s too big will short cycle, waste energy, and leave moisture in the air.
With R32 PTAC units, the rules are mostly the same — but their higher efficiency means you can often get the job done with a slightly smaller unit than older R410A systems.
Here’s the practical breakdown.
📊 General Sizing Chart for R32 PTAC Units
| Room Size (Sq Ft) | Typical Ceiling | Recommended BTUs |
|---|---|---|
| 150–250 | 8 ft | 7,000–9,000 BTU |
| 250–350 | 8–9 ft | 9,000–12,000 BTU |
| 350–500 | 9 ft | 12,000–15,000 BTU |
| 500–700 | 9–10 ft | 15,000–17,000 BTU |
📎 Tony’s Tip: In humid coastal regions (like Florida or the Gulf), size up by 1,000–2,000 BTUs to account for latent heat.
🧠 Key Variables to Factor In
1. Insulation Quality
-
Newer buildings (post-2000) can often use smaller units due to tighter construction.
-
Older properties with thin walls or leaky windows should size up or consider supplemental insulation.
2. Window Exposure
-
South or west-facing rooms that get full sun? Add 10–15% capacity.
-
Heavy drapes or low-E glass? You may not need to adjust.
3. Ceiling Height
-
Every extra foot of ceiling adds 5–10% more air volume.
-
For 10-ft ceilings, jump to the next BTU tier.
4. Occupancy & Equipment
-
Double occupancy or rooms with kitchenettes, fridges, or electronics produce extra internal heat.
-
Add 600–1,000 BTUs for each additional heat source.
5. Interior vs Exterior Rooms
-
Rooms with exterior walls need more cooling than interior suites or hallways.
🏨 Hospitality-Specific Guidelines
| Room Type | Recommended BTU Range | Notes |
|---|---|---|
| Hotel room (250–350 sq ft) | 9,000–12,000 BTU | Most standard rooms with 1–2 guests |
| Suite w/ kitchenette (350–450 sq ft) | 12,000–15,000 BTU | Consider extra load from appliances |
| Senior living private suite | 9,000–12,000 BTU | Often shaded and lightly occupied |
| Large ADA-compliant room | 12,000–15,000 BTU | Usually higher ceilings and square footage |
| Dormitory room (shared) | 9,000–12,000 BTU | Double occupancy adds internal load |
🧰 Tony’s Tip: Always double-check actual square footage — don’t rely on floor plans alone. I bring a laser tape to verify in the field.
🧮 Rule-of-Thumb Formula
Want to ballpark it yourself?
Example:
-
300 sq ft room x 25 = 7,500 BTUs
-
Add 1,000 BTUs for sun exposure
-
Add 500 BTUs for fridge or microwave
🟰 You’d want a 9,000–10,000 BTU R32 PTAC for that room.
🛑 Oversizing Risks (Don’t Make This Mistake)
If your unit is too powerful:
-
It’ll cool too quickly, then shut off
-
Humidity won’t be removed properly
-
Compressor wears down faster
-
Tenants complain about a “clammy” or “stale” feel
Trust me — bigger isn’t always better in HVAC. Go for accurate sizing, not overkill.
✅ Go-To Models from The Furnace Outlet
For most commercial jobs, I recommend these ranges:
-
9,000 BTU R32 PTAC – For small guest rooms, senior housing
-
12,000 BTU R32 PTAC – For standard hotel rooms and shared dorms
-
15,000 BTU R32 PTAC – For large suites or ADA-compliant rooms
They’re in stock, compliant, and ship fast from The Furnace Outlet.
📎 Bonus: Sizing Audit Checklist (For Retrofits)
-
❒ Measure room (L × W)
-
❒ Check ceiling height
-
❒ Note wall/window orientation
-
❒ Evaluate insulation condition
-
❒ Count internal heat loads (TVs, fridges, guests)
-
❒ Match BTU range to actual conditions
Use this list before placing large bulk orders — you’ll reduce mismatches and limit returns.
Wrapping It Up
Getting R32 PTAC sizing right means:
✔️ Better comfort
✔️ Lower utility bills
✔️ Longer unit lifespan
✔️ Happier guests, tenants, or residents
And with a little prep, it’s one of the easiest upgrades you can make across a whole property.
Need help scoping your building or ordering the right mix? I can help spec the job or get you started with a quick audit form.
Next topic will cover: "Why R32 Is the Future of PTAC Refrigerants" Explains global warming potential (GWP), ozone impact, and comparisons with R410A.
