The most common question I get from small business owners has no single right answer: "What should I buy to heat and cool my shop?"
I've been managing procurement for a 45-person food distribution company for 7 years. Our facility climate control budget runs about $120K a year, I've negotiated with 15+ HVAC vendors, and I track every repair order in a cost system. So I have opinions. But my honest take is that the best option depends on your scenario—not on what's trending, not on what a sales rep pushes hardest.
Here are your realistic options:
- A kerosene heater for emergency or occasional heat
- A Gree mini split 12000 BTU for small permanent spaces
- A Gree GS-18PITH11W 1.5 ton inverter AC for larger spaces with serious winter heating needs
- A thermostat replacement if your existing unit is actually fine
Let me walk through each one. And I'll get to the small freezer question too, since that comes up more often than you'd think when people are setting up a workspace.
Scenario A: You Need Heat Right Now, or Only a Few Hours a Week
If your heat died in January and your crew is standing around in coats, you don't have time for an installation. I've been there. A few years back, our main heating unit failed on a Monday when the forecast was 12°F. I had 4 hours to decide before the team lost a full workday. Normally I'd get three quotes and run a comparison, but there was no time. I bought a kerosene heater.
In that situation, a kerosene heater is a legitimate stopgap. A decent one runs $150–250; kerosene costs around $8–12 a gallon depending on your region. It kept our 1,500 sq ft work area warm enough to operate. But I want to be clear: it's not a long-term solution. You'll spend more on fuel in one bad winter than the difference in price between it and a proper heat pump. It also needs ventilation, which in a sealed building means cracking windows—so you're paying to heat the outdoors. And it's a fire risk. We kept ours near some cardboard packaging once and I didn't sleep well that night. We now have a formal safety checklist for portable heaters (I really should've made that after the first near-miss, not the second).
However, there's another legitimate kerosene heater scenario: occasional use. If you only heat the space a few hours a week—weekend projects, a storage area you check on briefly, a loading dock office—a kerosene heater can be the most cost-effective option, period. You just have to be honest about your usage pattern.
Scenario B: Small Permanent Space (Under 400 Sq Ft)
If you need year-round heating and cooling for a small workshop, a kiosk, a detached office, or a server room, the Gree mini split 12000 BTU is the unit I spec most often. Here's the real math from a project we did last year.
We have a 350 sq ft shipping office that was running on two space heaters and a window AC unit that should've been retired years ago. Monthly electric cost: $85–110 in summer, $95–130 in winter. The window unit finally died in July, right before inventory week.
Quotes: a basic through-wall AC installed was about $650. A Gree mini split 12000 BTU installed was $1,400–1,800. I hesitated on the mini split. The cheaper option would've done the job, and being honest, budgets were tight that quarter.
But when I compared total cost of ownership over 5 years instead of just purchase price, the mini split won. Inverter compressors run efficiently at partial load, so they don't cycle on and off at full power like older units. The SEER2 rating on a mini split is typically in the high teens to low 20s; a basic through-wall unit is lucky to hit 12. Our electric bill dropped to $45–60 a month. The payback on that $1,000 premium was about 20–24 months. After that, it's savings.
The small freezer connection: if you also need a freezer in that space for a break room, a restaurant, or sample storage, consider having the electrician add a dedicated outlet while they're mounting the mini split. It saves a second service call. And look for a compact freezer with inverter compressor tech—same variable-speed principle. They use noticeably less energy than the older plug-in models that cycle at full power.
Don't hold me to those exact savings in every region—electricity rates, insulation, and use patterns vary. But the efficiency gap between a basic 12 SEER unit and a better-rated inverter system is consistent, and it's not small.
Scenario C: Larger Space, Cold Winters, Primary Workspace
This is where the Gree GS-18PITH11W 1.5 ton inverter AC comes in.
The 12000 BTU mini split is great for cooling and mild heating. But if you're trying to heat 700–1,000 sq ft in an area where winter temps regularly drop below freezing, you need more capacity and low-ambient heating capability—not just a bigger cooling unit.
The GS-18PITH11W is designed for heating output at outdoor temps down to -25°C/-13°F, based on the manufacturer's spec sheet. That's the critical spec for cold climates. A lot of standard heat pumps lose heating capacity right when you need it most: below roughly 30°F, output falls off and you start burning through expensive backup electric resistance heat.
Things I'd verify with any dealer before buying:
- Actual heating output at your local average winter low, not just the nominal rating
- SEER2 and HSPF2 ratings—these are the current industry standard metrics; older SEER/HSPF numbers aren't directly comparable
- Line set length included in the quote
That last one cost me once. A contractor quoted us a unit without checking the distance between the outdoor condenser and the indoor head. The install worked, but efficiency was terrible. We didn't have a formal commissioning checklist back then. The third time a quote came in with no line-set spec, I finally built one and made it a requirement for every project.
Also, a quick flag: per FTC guidelines (ftc.gov), claims about specific energy savings need to be substantiated. So if a dealer tells you "this will cut your bill 40%," ask for the written calculation. If they can't produce one, that's not a great sign.
Scenario D: The Unsexy Option—Fix What You Have
This is the scenario people skip, and it's why so many searches land here: how to change a thermostat.
Before you drop $1,500 on a new system, ask yourself: does the existing unit actually run fine, but the temperature reads wrong? Does the blower kick on but the compressor never starts? Does the display show gibberish?
A basic thermostat replacement costs $15–50 for the device, or $100–200 for an electrician if you don't want to touch low-voltage wiring. I've swapped several myself. The process for most systems:
- Turn off power at the breaker. Non-negotiable—I say that because people skip it.
- Remove the old faceplate. Take a photo of the wiring before you touch anything.
- Label the wires as you disconnect them.
- Match the new thermostat terminals (typically R, W, Y, G, C for a conventional system).
- Snap on the faceplate and restore power.
Heat pump systems are a bit different—you'll likely have an O/B terminal instead of just W. Check the wiring guide for your specific thermostat model. Roughly speaking, most thermostat issues come down to dead batteries, loose wiring, or a failed sensor. None of those require a new HVAC unit.
The decision rule I use: if the system runs nonstop and never reaches set point, that's a capacity problem, and a new thermostat won't help. But if the system isn't running at all, or runs at random times, it's usually a control problem—and a $30 thermostat might be the whole fix.
One more story. I bought a $12 thermostat for our break room once instead of the $80 model that was easier to program. The cheap one confused everyone. The temp got set to 80°F constantly (ugh), and cooling energy in that zone ran about 40% higher than the previous year. The "budget" thermostat cost us more in one summer than the $68 difference. Penny wise, pound foolish.
How to Know Which Scenario You're In
Here's the 2-minute self-diagnosis I use with our own facilities and with owners who ask:
- How urgent is it? Heat is dead and crew arrives tomorrow morning? Scenario A. Get a kerosene heater as a stopgap today, but schedule a permanent solution evaluation within the week.
- What's the space size and how often do you use it? Under 400 sq ft, daily use, need both heating and cooling → Scenario B: the Gree mini split 12000 BTU. Over 500 sq ft, cold winters, primary workspace → Scenario C: the GS-18PITH11W 1.5 ton inverter AC. A few hours a week → Scenario A.
- Does your current system actually run? Yes, but controls are wonky? Scenario D. Change the thermostat first—it's the cheapest test and takes an afternoon.
The mistake I see over and over—from owners and even other procurement people—is jumping to the biggest solution first. The size and frequency of your actual use should drive the decision, not what feels like the "right" purchase.
And one last thing, since I get asked about this a lot: don't accept being treated like a small customer who doesn't matter. We were a tiny operation when we bought our first units, and the vendor who took that small order seriously is the one we still call today. Small doesn't mean unimportant—it means potential. A vendor who dismisses your small job is showing you how they'll handle your warranty claims later.
If you want a more targeted take, drop your specifics—space size, climate zone, current equipment—and I'll tell you which of the four paths I'd take with your numbers.
