Des Moines / Grinnell
Grinnell has 9,505 residents (give or take 52) (ACS 2020-2024 5-year, table B01003, https://data.census.gov/table/ACSDT5Y2024.B01003?g=160XX00US1933105, checked 2026-10-19), about 1,671 people per square mile.
Grinnell is about 47 miles from the Census center point for Des Moines in a straight line and covers 5.689 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).
Of the 3,635 occupied homes in Grinnell, 62% heat with natural gas, 0% with heating oil, 33% with electricity and 1% with propane (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=160XX00US1933105, checked 2026-10-19).
Gas heats 62% of Grinnell against electricity at 33%, so most quotes here are a partial-home system that carries the shoulder seasons and the summer while the gas furnace handles the coldest nights, or a whole-home system when the house is ready for it.
Grinnell has about the Poweshiek County oil share of 0% and 7 points more electric heat than the county's 26% (ACS 2020-2024 5-year, table B25040, https://data.census.gov/table/ACSDT5Y2024.B25040?g=050XX00US19157, checked 2026-10-19).
Grinnell has 3,976 housing units, 29% built before 1940 and 64% before 1980, with 17% built in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US1933105, checked 2026-10-19).
Grinnell tracks Poweshiek County on housing age, with the county at 29% pre-1940 and 18% post-2000 (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=050XX00US19157, checked 2026-10-19).
The median Grinnell home was built in 1971 (ACS 2020-2024 5-year, table B25035, https://data.census.gov/table/ACSDT5Y2024.B25035?g=160XX00US1933105, checked 2026-10-19) and the median home has 6.2 rooms (ACS 2020-2024 5-year, table B25018, https://data.census.gov/table/ACSDT5Y2024.B25018?g=160XX00US1933105, checked 2026-10-19).
63% of Grinnell homes are single-family detached, 7% are in two- to four-unit buildings and 20% are in buildings of five or more units (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=160XX00US1933105, checked 2026-10-19).
35% of Grinnell homes are rented (ACS 2020-2024 5-year, table B25003, https://data.census.gov/table/ACSDT5Y2024.B25003?g=160XX00US1933105, checked 2026-10-19), so beside the 63% detached houses there is a real share of jobs where the landlord, not the resident, signs the quote.
Grinnell has 14 points fewer detached houses than Poweshiek County overall (77%) and 11 points more five-plus-unit buildings than the county's 9% (ACS 2020-2024 5-year, table B25024, https://data.census.gov/table/ACSDT5Y2024.B25024?g=050XX00US19157, checked 2026-10-19).
64% of Grinnell homes were built before 1980 and only 17% in 2000 or later (ACS 2020-2024 5-year, table B25034, https://data.census.gov/table/ACSDT5Y2024.B25034?g=160XX00US1933105, checked 2026-10-19), so most of the stock predates modern insulation codes; the installer's heat-loss calculation, not a square-footage rule, decides the tonnage.
No electric utility is on file for Grinnell on this door yet, so this page does not name one; the name on the bill decides which rebate path applies.
MidAmerican 2026 Instant Discount air source heat pump, run by MidAmerican Energy, is a live program for Iowa addresses and covers qualifying equipment at $1,200 per system (registry row 31 verified 2026-10-14, https://www.midamericanenergy.com/home-discounts-and-rebates, checked 2026-10-16); confirm eligibility for the Grinnell address before counting it. With 33% of Grinnell homes already on electric heat and 63% on gas, oil or propane, the row that applies depends on the name on the electric bill and the fuel coming out.
Median household income in Grinnell is $65,320 (ACS 2020-2024 5-year, table B19013, https://data.census.gov/table/ACSDT5Y2024.B19013?g=160XX00US1933105, 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.
Heating design temperature: -5F. Source: ENERGY STAR Design Temperature Limit Reference Guide (2019 Edition), Poweshiek County row, 99% heating, PDF pages 37 to 41 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 -5F figure is the Poweshiek County cold-day number a Grinnell heat pump is sized against, so ask the installer to show the system's heating output at -5F, not at the milder rating-label temperature.
Ask whether the quote is whole-home or partial-home, because with 62% of Grinnell on gas and 33% already electric the two paths carry different rebate figures and different sizing.
Ask for the heat-loss calculation room by room; the median Grinnell home has 6.2 rooms and was built around 1971, 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 Grinnell. The public number is the number the contractor quotes from.
No local contractor is named on this door for Grinnell yet. A request from this page goes to the first licensed shop that takes the door.