I bought an aranet 4, it's quite eye opening how you sometimes get a lot of CO2 buildup without even noticing.

I mostly solve any issues with VOC by "Stosslueften", but if that's not enough because the air quality outside is too bad, a CR box is an effective, easy to build and almost perfectly silent design, especially if you do it with decent quality pc fans.

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agwa 4 days ago | parent [-]

A CR box only removes particulates, not VOCs. To remove VOCs, you need a filter with many pounds of activated carbon.

	▲	fnordian_slip 3 days ago \| parent [-]
		Ah, my bad, I thought that everyone built CR boxes with carbon, but that's not the case. The standard design doesn't use carbon at all. Thanks for the correction.