Whole-Home Heat Pump Upgrade in Arlington, MA: Mitsubishi Hyper Heat Mini Split Installation Replaces Steam Heat

A Big Comfort Upgrade for a Classic Arlington Home

Tucked in the heart of Arlington, Massachusetts, this 1926 three-bedroom single-family home had recently undergone comprehensive weatherization upgrades. With updated insulation and air sealing in place, the homeowner was ready for the next step in energy efficiency and comfort: replacing the aging natural gas-fired steam heat system.

That’s where Denommee Plumbing, HVAC & Electric stepped in.

Leveraging our experience as a Mass Save Heat Pump Installer Network (HPIN) contractor, we designed and installed a high-performance, 36,000 BTU Mitsubishi multi-zone Hyper Heat mini split system. The result? Year-round comfort, better zoning, lower utility bills, and access to over $12,000 in rebates and tax credits.

Why This Home Was a Perfect Candidate for a Heat Pump

Older homes like this 1,330-square-foot colonial often come with outdated hydronic or steam heating systems and no central air conditioning. While charming, these setups offer limited zoning and can be expensive to run.

Thanks to recent weatherization upgrades, this home had the insulation levels needed to support a heat pump system that would deliver efficient heating in New England winters and cooling in the summer.

By transitioning to a Mitsubishi Hyper Heat mini split system, the homeowner could:

• Replace inefficient steam heat

• Gain energy-efficient cooling and heating

• Qualify for Mass Save’s $10,000 whole-home heat pump rebate

• Lock in 0% HEAT Loan financing

• Receive a $2,000 federal tax credit under the Inflation Reduction Act

The System: Mitsubishi 3-Zone Mixed-Ducted Hyper Heat Heat Pump

We specified a 3-ton (36,000 BTU) Mitsubishi system designed for all-season performance, including cold-climate heating.

Equipment Details:

Outdoor Unit:

• Make: Mitsubishi

• Model: MXZ-SM36NAMHZ2

• Type: Inverter-driven, Variable Capacity Heat Pump

• Hyper Heat: Yes (H2i)

• AHRI Cooling Capacity (95°F): 36,000 BTU

Indoor Units (3-Zone System):

1. MLZ-KY06NA – One-way ceiling cassette – Rear Left Bedroom – 6,000 BTU

2. MLZ-KP09NA – One-way ceiling cassette – Kitchen – 9,000 BTU

3. SVZ-KP18NA – Multi-position ducted air handler – Whole-Home Zoning – 18,000 BTU

Branch Box:

• PACMKA32BC – Connects the multi-zone system for optimal control and refrigerant flow

This setup offers targeted comfort, balancing ducted coverage for common areas with ceiling cassettes that preserve aesthetics and headroom in smaller rooms.

New Ductwork Installation: Precision and Efficiency in the Attic

A key element of this project was the design and installation of a custom attic ductwork system. Our team installed a new 1.5-ton ductwork system composed primarily of galvanized hard-pipe for durability and optimal airflow.

Ductwork Scope Included:

• Full hard-pipe supply and return trunk lines

• Sealed seams and fully insulated runs

• 4 to 5 supply registers and 1 to 2 returns

• Hangers, vibration blocks, diffusers, and air filters for performance and longevity

This attic-based layout minimized the need for visible soffits or disruptive retrofitting, preserving the home’s character while adding modern comfort.

Code-Compliant Electrical Work by Denommee’s In-House Electricians

As a full-service HVAC and electrical contractor, Denommee’s in-house electricians provided seamless integration of the heat pump system’s power and controls.

Electrical Scope Included:

• Installation of a new dedicated AC electrical feed

• Two-pole breakers, outdoor disconnects, and whips

• High-capacity wiring to support variable capacity equipment

• New attic service wiring – fully code-compliant and professionally installed

Having licensed electricians as part of our team allows us to coordinate every phase in-house, reducing delays, ensuring safety, and keeping quality control at the highest standard.

Instant Rebates, Long-Term Savings

Thanks to Denommee’s HPIN contractor status, this project qualified for some of the most generous incentives available under the Mass Save program.

Incentive Breakdown:

• ✅ $10,000 Mass Save Whole-Home Heat Pump Rebate

• ✅ 0% Interest HEAT Loan up to $50,000

• ✅ $2,000 Federal Tax Credit

That’s over $12,000 in upfront and long-term value, dramatically reducing the cost of upgrading to high-efficiency electric heating and cooling.

Why Homeowners Choose Denommee for Whole-Home HVAC Upgrades

Whether it’s a full steam heat replacement or a hybrid heating system, homeowners trust Denommee for:

• 🏡 Proven experience in retrofitting older homes

• ⚡ In-house electricians for complete electrical scope

• 🌱 Mass Save HPIN contractor status for rebate maximization

• ❄️ Certified Mitsubishi Diamond Contractor expertise

• 🛠️ Seamless project management from design to install

• 📍 Local service coverage in Arlington and throughout Middlesex County

Final Result: Comfort, Control, and Efficiency

With this mixed-ducted Mitsubishi Hyper Heat system, the homeowner now enjoys:

• Whisper-quiet operation

• Zoned temperature control

• Efficient cooling in summer and heating even on subzero days

• Major savings on energy bills

Plus, the home is now better prepared for a fully electrified future, free from fossil fuels.

Thinking of Replacing Steam Heat in Your Home?

If you own an older home in Arlington, Cambridge, Belmont, or nearby towns, it may be a perfect candidate for a heat pump system like this one.

And with the current rebates and financing programs, there’s never been a better time to upgrade.

👉 Contact Denommee Plumbing, HVAC & Electric today to schedule a free consultation and explore your heat pump installation options.