How to?Reviewed: 2025-12-27~1 min

How to cool down a house without AC during a heatwave in an older brick home

Short answer

⚠️Depends / use caution

It depends—older brick homes can stay cooler if you manage their thermal mass and ventilation well, but layout, wiring, and window type will affect what works safely.

Why people ask this

Because brick holds heat, older masonry houses can feel like ovens after a few hot afternoons. People living through a heatwave in a pre-insulated era home want cooling that works with thick walls, small vents, and aging electrical. They’re also juggling sash or single-pane windows, limited attic insulation, and sometimes knob-and-tube wiring that complicates fan use. Understanding night flushing, exterior shading, and safe use of portable equipment helps tailor a plan that fits older brick construction.

When it might be safe

Night-flush ventilation: place box fans in upper windows exhausting hot air and open shaded lower windows to pull in cooler night air; close up by late morning to trap the cool in the brick’s thermal mass.
Exterior shading for masonry: temporary shade cloth or awnings on west- and south-facing brick to cut radiant gain without trapping heat against the wall.
Reflective, removable window treatments: exterior-grade shades or interior cellular blackout blinds with side tracks on single-pane windows.
Targeted attic ventilation: run a powered attic/roof fan only if wiring is modern and attic is air-sealed from living space, to reduce roof-deck heat soaking into lath-and-plaster ceilings.

When it is not safe

Running charcoal grills, propane heaters, or unvented gas appliances indoors for heat avoidance—this risks carbon monoxide poisoning.
Overloading old circuits with multiple high-wattage fans or a portable cooler on the same outlet, especially in homes with knob-and-tube wiring.
Sealing the house all day without a nightly purge in a brick home—masonry can release stored heat overnight and push indoor temps dangerously high.
Hosing exterior brick repeatedly in full sun to ‘cool’ walls—can cause spalling, efflorescence, and moisture intrusion in older mortar.
Blocking bedroom egress windows with box fans or fixed panels, reducing escape routes in an emergency.

Possible risks

Heat-related illness if indoor temperatures stay above 80–85°F overnight due to brick thermal lag.
High indoor humidity from evaporative coolers or steam cooking, leading to condensation on single-pane windows and potential mold in plaster walls.
Electrical hazards from daisy-chained extension cords to reach upper sash windows or attic fans.
Poor indoor air quality if attic or chimney pathways draw dusty, unconditioned air during aggressive exhaust strategies.
Cracking or damage to old glazing putty or paint when applying/removing temporary films or panels in extreme heat.

Safer alternatives

Create a ‘cool room’: use one efficient window or portable heat-pump unit on a dedicated circuit, seal that room with door sweeps and reflective curtains.
Spend peak hours in a community cooling center or library; return to a pre-cooled home after sunset for night flushing.
Install exterior awnings or shade sails on west-facing brick and upgrade to low-leakage storm windows to cut heat gain without full window replacement.
Use a window-mounted reversible fan pair (intake low/shade side, exhaust high/sunny side) to enhance stack effect in tall stairwells common to older homes.
Weatherization steps that help right away: attic hatch gasket, temporary door sweeps, and reflective film on the hottest exposures.

Bottom line

Leverage the brick’s mass: purge heat at night with controlled cross-ventilation, then seal and shade aggressively by day, adding targeted, safe fan use and exterior shading. Avoid moisture and electrical hazards common in older homes, and consider a single cooled room or community spaces during peak heat.