Look, I get it. You're staring at two quotes—one for a Dimplex heat pump, one for a high-efficiency furnace—and wondering which one won't come back to haunt you. I've been in the HVAC game for about 12 years now, coordinating installations for residential and light commercial clients. I've seen both systems fail, succeed, and everything in between. This FAQ covers the questions I get asked most, plus one you probably haven't thought of.
1. Is a Dimplex heat pump actually cheaper to run than a furnace?
Short answer: it depends on where you live and your local electricity-to-gas price ratio. In my experience (mostly Mid-Atlantic US, circa 2024), the Dimplex heat pump cut heating costs by roughly 25-40% compared to a standard 80% AFUE gas furnace during mild winters. But here's the catch—once temps drop below freezing, the efficiency differential narrows.
I've seen situations where a client saved $400 over the winter with a heat pump, only to have that savings wiped out by a single emergency repair (more on that in a sec). The numbers on paper won't always match your real bill because of defrost cycles, backup heat strips, and your specific thermostat settings.
"For a medium-sized home (2,000 sq ft), we ran the numbers based on Q4 2024 utility rates. Heat pump: ~$800-1,100/year. Gas furnace: ~$1,200-1,600/year. But those heat pump numbers assume no electric backup is running full-time."
2. Do Dimplex heat pumps work in cold weather?
Yes, but with a deliberate asterisk. Dimplex has some cold-climate models that work down to -15°F. I installed one for a client in March 2024—36 hours before a snowstorm, actually—and it performed fine. That said, performance drops noticeably below 20°F. The COP (coefficient of performance) goes from around 3.5 at 47°F to maybe 1.8 at 5°F.
For most people, the real question isn't "does it work?" but "will I need backup heat?" And the answer is: if you live somewhere it hits single digits regularly, you probably will. That backup can be an electric heat strip or a gas furnace. Some folks pair a Dimplex heat pump with a smaller gas furnace for the coldest weeks (not a bad idea, honestly).
3. What about the Dimplex flat fan heater—is that any good?
I get asked about the Dimplex flat fan heater more than you'd think. It's not a heat pump, obviously—it's a resistance heater with a fan. I've used them in server rooms, garages, and as temporary heat during renovations. They're reliable, simple to install, and maintenance is basically zero (no filters to change).
The downside? They're not efficient. They cost about the same to run as an electric furnace—roughly 3x the cost of a heat pump for the same heat output. Great for spot heating, terrible for whole-home heating. If you're comparing a flat fan heater to a heat pump for a living room? Heat pump wins every time, unless you're just using it a few hours a day.
4. Can I use a 16x20x1 air filter with my Dimplex system?
Depends on your specific unit. Most Dimplex heat pump air handlers take standard 1-inch filters. The 16x20x1 size is common for residential systems, but check your cabinet specs before ordering. I've seen people buy the wrong size and try to bend the filter (don't do that).
One thing I've learned from 200+ installations is that filter quality matters more than most people think. A cheap fiberglass 16x20x1 air filter (like the ones for $2 each) lets tons of dust through, which cakes on the evaporator coil and kills efficiency. Spend the extra $2-3 for a MERV 8 pleated filter. Change it every 3 months—or monthly if you have pets or allergies (ugh, pet dander is the worst on HVAC systems).
5. What's a Dimplex oil free heater? Should I buy one?
Ah, the Dimplex oil free heater. This is a confusing product name, honestly. It's not oil-filled (like traditional radiator-style oil heaters), it's just a ceramic or fan-forced heater. The "oil free" tag is marketing to distinguish from those old oil-filled units that can leak.
I've used them for spot heating in offices and small apartments. Are they better than a heat pump? No—they're not designed to heat whole homes. But if you need a portable, safe, quiet heater for a single room in the shoulder season, they're fine. Proceed with caution if you plan to use one as your primary heat source in a cold climate—you'll be paying a lot more than with a heat pump system.
6. Do I need to change the air filter in my car to match my HVAC system?
This question pops up because people see "air filter car" and think the same filter works for both. It doesn't. Your car's cabin air filter (often around 20x20x1 or similar in some vehicles) is unrelated to your home's 16x20x1 air filter. Different sizes, different MERV ratings, different purpose.
I once had a client try to install a car air filter in their HVAC system because "it was cheaper"—surprise, surprise, it didn't fit and didn't filter properly. Stick to the right filter for each system. For your Dimplex heat pump, use a standard 1-inch home air filter. For your car, use a cabin air filter from an auto parts store.(based on 2024 prices; always verify current costs).
This was accurate as of late 2024. Energy markets and technology change fast—especially with heat pump incentives and stricter efficiency standards—so always verify current pricing and local availability before making a decision.