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Severe black mold...heat exchanger??? Answered

Hi! we have this severe problem of black mold in every room, the wall is black... Water puddles on the floor.... Our surveyor and a builder told us (after cheeking everything) to solve the problem with a heat exchanger in every room... we are trying one in the kitchen but after 2 weeks i still found water on the floor and the mold in the corner seems increased... someone tried that?

The cause of the mold are heat bridges and non existin insulation...



1 year ago

Any mold problems need to be addressed before any additions (like a heat exchanger). That means spraying a mold mitigation agent (from a big box store like Lowes, Home Depot). It's possible that drywall needs to be removed first -- not great news, I know.

Preventing these issues depends on:

-- Your environment (is it damp year-round? Hot? Cool?)

-- building type/construction (largely masonry?)

-- has the building been flooded? If so, was it properly rehabbed?

-- how's the drainage? Gutters or eaves? Sump pumps?

Ironically, heat exchangers are often needed for super-insulated homes (no way for moisture to escape) in cooler environments. A poorly or non insulated would definitely need ventilation, but not necessarily heat exchangers everywhere, unless the building is tightly sealed most of the time.

Is it a cold environment? Insulation, vapor barriers, etc. would be called for.

You probably shouldn't be living the home if there is black mold in every room...


1 year ago

A heat exchanger unit can help solve some mold issues, but it is usually fitted on a house-wide basis. It exchanges warm stale air from within the house with fresh air from outside (whilst maintaining the heat with a high efficiency).

However if your mold is that severe and you are also finding water on the floor I suspect the mold is a symptom of a greater problem. A heat exchanger is not likely to deal with a problem so severe that you are seeing water on the floor.

First things to check in these situations are the rain gutters and the, also check for signs of damp patches on the exterior walls / render.

Another thing to consider is whether any of the grounds around the outside of the house are higher than any of the interior floors, this can create damp if the house is not properly 'tanked'.

Do you know what the construction of your house is? (i.e. timber frame, stone walls, brick, with or without cavity walls).

Does the damp / mold problem appear to be worse on any particular aspect of the house? (i.e. any particular face / exterior wall).

Like the others have said, seek professional advice. I know you've had a surveyor and a builder look at it already bit I'd definitely get another opinion.

Josehf Murchison

1 year ago

Black mold can be bad.

Heat exchanger or a dehumidifier?

A heat exchanger is the wrong device you need a dehumidifier.


Dry the house with a dehumidifier.

Wash with soap and water, not bleach or ammonia.

Wash everything ceiling, walls, floor, furniture, blankets, curtains, clothing, and anything organic. Even remove your house plants, and hope the mold is not in the walls.

After a certain point black mold can get a home condemned; contents and all, so you might want to consult a professional.

randofoJosehf Murchison

Reply 1 year ago

Ammonia definitely inspires mold growth, but it has been my understanding that bleach kills mold. Only problem with bleach is that it can't kill mold if it is a porous surface like drywall and it is rotten through.

Either way, you're right, they should consult a professional...