Arlington / Merrifield
Merrifield has 20,698 residents (give or take 1,349) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=160XX00US5151192, checked 2026-10-19), about 7,669 people per square mile.
Merrifield is about 7 miles from the Census center point for Arlington in a straight line and covers 2.699 square miles of land (Census 2024 Gazetteer internal points and land area, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/, checked 2026-10-19).
The quote form takes a ZIP code; for Merrifield that is 22031 (Census 2020 ZCTA to county subdivision and ZCTA to place relationship files, ZIP areas at least 20% inside the town, https://www2.census.gov/geo/docs/maps-data/data/rel2020/zcta520/tab20_zcta520_cousub20_natl.txt and https://www2.census.gov/geo/docs/maps-data/data/rel2020/zcta520/tab20_zcta520_place20_natl.txt, checked 2026-10-19).
Median household income in Merrifield is $136,373 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=160XX00US5151192, checked 2026-10-19); many state and utility heat pump rebate programs set higher incentive tiers for income-qualifying households, so the household income on the application, not the town median, decides which level applies.
7,669 people per square mile puts Merrifield in suburban density, where the outdoor unit usually sits in a side yard and the noise is not an issue for neighbors.
11% of Merrifield homes are single-family detached, 2% are in two- to four-unit buildings and 62% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=160XX00US5151192, checked 2026-10-19).
With 62% of Merrifield homes in buildings of five or more units and 11% detached, the condo association usually decides where outdoor units can go, so that approval comes before the quote. With 61% of Merrifield homes rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US5151192, checked 2026-10-19), the landlord signs the quote in many of them.
Merrifield has 35 points fewer detached houses than Fairfax County overall (46%) and 33 points more five-plus-unit buildings than the county's 29% (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=050XX00US51059, checked 2026-10-19).
With 61% of Merrifield homes rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US5151192, checked 2026-10-19), most heat pump quotes here are landlord-driven: the landlord signs the contract and picks the equipment, and the tenant sees the lower bill.
Of the 9,435 occupied homes in Merrifield, 45% heat with natural gas, 1% with heating oil, 52% with electricity and 2% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=160XX00US5151192, checked 2026-10-19).
Electricity already heats 52% of Merrifield homes, ahead of gas at 45%, and a home on electric baseboard sees the biggest bill change from a heat pump because it replaces resistance heat one for one.
Merrifield has about the Fairfax County oil share of 1% and 10 points more electric heat than the county's 42% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US51059, checked 2026-10-19).
No electric utility is on file for Merrifield on this door yet, so this page does not name one; the name on the bill decides which rebate path applies.
Merrifield has 9,853 housing units, 1% built before 1940 and 32% before 1980, with 54% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US5151192, checked 2026-10-19).
Merrifield has 34 points more homes built after 2000 than the county's 20% (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US51059, checked 2026-10-19).
The median Merrifield home was built in 2001 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=160XX00US5151192, checked 2026-10-19) and the median home has 3.8 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=160XX00US5151192, checked 2026-10-19).
54% of Merrifield housing was built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US5151192, checked 2026-10-19), and homes that recent usually meet the insulation codes in place at the time, so a heat pump sized to the floor plan lands closer to the real load than it would in an older neighborhood.
Heating design temperature: 14F. Source: ENERGY STAR Design Temperature Limit Reference Guide (2019 Edition), Fairfax County row, 99% heating, PDF pages 127 to 133 of 141 (Revised 11/11/2020), https://www.energystar.gov/sites/default/files/Design%20Temperature%20Limit%20Reference%20Guide%20(2019%20Ed)%20-%20ENERGY%20STAR%20Single-Family%20New%20Homes_Rev11.pdf, fetched 2026-10-19, 99%.
That 14F figure is the Fairfax County cold-day number a Merrifield heat pump is sized against, so ask the installer to show the system's heating output at 14F, not at the milder rating-label temperature.
Ask for the heat-loss calculation room by room; the median Merrifield home has 3.8 rooms and was built around 2001, and the count of heads and the tonnage follow the rooms and the insulation, not the square footage.
The form on this page is the follow-up for Merrifield. The public number is the number the contractor quotes from.
No local contractor is named on this door for Merrifield yet. A request from this page goes to the first licensed shop that takes the door.