Unvented Crawlspace Air mixing
我目前正在拥有一个没有透明的爬行空间，SE田纳西州的房子，炎热潮湿的3个赛季。该结构如下：工程墙系统（混凝土，带有嵌入式金属螺柱，绝缘），通过爬行空间，带有2“混凝土板的2”混凝土板，在板坯下安装了障碍物。没有开口到外面，进入位于部分地下室的爬行空间。4'高墙。换句话说，爬行空间是像一个连接到实际地下室的4'高大地下室一样。
I am currently weighing my ERV/HRV/air mixing options. I need to decide what the best approach is to dealing with the crawlspace air. Since it is constructed as a mini basement, do I treat this as a good source of air and encourage mixing this with the house in order to dehumidify the crawlspace air? Or is it best to separate this air as its own thing?
One option I have considered is supplying fresh air to the crawlspace through an ERV and exhausting air from the master bathroom. Then providing open registers from the crawl to several locations in the house above. As the house is ventilated (hopefully) it will draw the fresh air from the crawlspace into the house and condition. I am thinking this will take care of humidity issues in the crawl through conditioning with the house, create an easy way to distribute fresh air throughout the house, and hopefully provide a known source of makeup air as negative pressure is created from the exhaust.
The flipside is, would drawing this air from the crawlspace have a negative effect and actually draw moisture and humidity from the ground and create a constant battle with this in the house. In other words, I can’t decide if this crawlspace is a “good” or “bad” source of air. Thoughts?
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Replies
Bryan,
史蒂夫朝着正确的方向转向你。代码要求在我的一个文章中解释，Building an Unvented Crawl Space. Whether or not the crawl space has "good air" or "bad air" is a matter of some debate; if you are worried, install a small exhaust fan in the crawl space rim joist, blowing out, and provide makeup air through a grille in the crawl space ceiling (the floor above).
While the article explains requirements in the International Residential Code, your local code may have different requirements -- so check with your local building department.
Bryan,
You may want to read this article (//m.etiketa4.com/blogs/dept/musings/building-unvented-crawl-space) on unvented crawl spaces. As the article notes, you can install a floor vent to allow air movement between the conditioned and unconditioned areas.
Does your ventilation plan include ducts that are separate from your HVAC system?
Do you have a small opening between the crawl space and basement?
If there are radon or mold smell issues, then crawlspace air is bad and should be exhausted.
Summer exterior air that has passed through an ERV is not as dry as interior air (ie, it's less effective at keeping it condensation free).