Adding Air Conditioning to a Home That Never Had It
Options for homes built with no cooling at all.
Updated October 27, 2026
A lot of older homes around Portland were built with no air conditioning. The summers were mild and the hot spells were short, so builders and buyers skipped it. If your Gresham house still has no cooling, this guide lays out the options from cheapest to most complete. To have a contractor look at the house, call (503) 755-9845.
Why this matters now
The U.S. Census Bureau American Housing Survey found that about 78 percent of Portland-area homes had air conditioning in 2019. That still left more than one home in five with none. Then came June 2021. Portland International Airport reached 116 degrees, the hottest reading on record there.
Multnomah County looked at the 54 hyperthermia deaths it had confirmed by mid-July. None of those people had central air. Twenty-eight had only a fan, thirteen had no cooling at all, and most of the eight with portable units had them unplugged or broken.
Your options, from least to most
Window and portable units
Cheap and quick, and better than nothing. They are loud, they cool one room, and many cannot keep up when it is over 100 outside. Portable units that vent one hose out the window are the weakest of the bunch.
Ductless mini-split
One outdoor unit feeds one or more wall heads. It is quiet, it heats too, and it needs no ducts. This is the usual pick for houses with baseboard heat or wall heaters.
Central AC on existing ducts
A house with a forced-air furnace already has ducts running to every room. The contractor sets a cooling coil on top of the furnace and an outdoor unit outside.
Heat pump on existing ducts
Same idea as central AC, but it also heats. Many owners keep the gas furnace as backup for the coldest east wind days.
Call to have a local contractor look at the house and price your options.
(503) 755-9845What to ask the contractor
- Will my ducts carry enough air for cooling, or do they need changes?
- Does my electrical panel have room for a new circuit?
- Where will the outdoor unit and the lines go?
- What permit does the job need, and who pulls it?
- Are there Energy Trust of Oregon incentives for this equipment right now?
Questions about Adding AC to an older home in Gresham
- Can I cool my whole house with window units?
- You can try, but it takes several units, runs up the power bill and still leaves hallways and some rooms hot. A ductless or ducted system cools more evenly.
- Is it too late to add AC before next summer?
- No. Fall and winter are a good time to get prices, because contractors have more open time than they do in a July heat wave.
Free to call. A person answers 24 hours a day and connects you with a local contractor.
(503) 755-9845