Re: Sink-level ventilation
I know this thread is quite old but posting here because this was one of the resources that I used when planning my recent darkroom build (discussed in this thread). I opted for the pvc pipe with holes that the OP originally asked about and after some testing, I found that the system was not effective for me. I’m using a 1202 CFM blower (so plenty of power and suction) but in the end, the pipe with holes just wasn’t able to create enough suction across the surface of the sink to adequately remove fumes/vapor per my tests using smoke from incense. I’ve posted this video which shows the smoke test and the change to the plan that I arrived at which does draw fumes (smoke in my test) off the surface of the sink from an adequate distance. Just posting this here for others who might find this as they decide what kind of system they want to use. Hope it’s helpful.
Re: Sink-level ventilation
I initially installed almost the exact same system (we probably got the idea from the same person) and found it ineffective as well.
I removed it and built a sink-long (8ft) system with slots that I can open or close, depending on where my trays are.
However, one exhaust fan was still not enough when I had trays from one end of the sink to the other; I added a second exhaust fan, midway along the system. It works to my satisfaction. The only downside is that is a little bit noisy, but not annoyingly so.
Re: Sink-level ventilation
Guys, go take a look at post #120 and post #122 in Daniel Unkefer's thread " Darkroom Renovation Phase 1". Dan used a driveway rainwater drain. That's pre-made and saves time-also the ones at Home Depot have a 4" connection for the drainpipe, so hooking it to 4" flex hose for a dryer would be very easy.
Re: Sink-level ventilation
Re: Sink-level ventilation
Quote:
Originally Posted by
Fragomeni
I know this thread is quite old but posting here because this was one of the resources that I used when planning my recent darkroom build (discussed in this
thread). I opted for the pvc pipe with holes that the OP originally asked about and after some testing, I found that the system was not effective for me. I’m using a 1202 CFM blower (so plenty of power and suction) but in the end, the pipe with holes just wasn’t able to create enough suction across the surface of the sink to adequately remove fumes/vapor per my tests using smoke from incense. I’ve posted
this video which shows the smoke test and the change to the plan that I arrived at which does draw fumes (smoke in my test) off the surface of the sink from an adequate distance. Just posting this here for others who might find this as they decide what kind of system they want to use. Hope it’s helpful.
This kind of makes sense when you think about. Air is just like water in that it's going to take the easiest route, so if you have one long pipe with holes in it guess which holes in the pipe get the majority of the air flow? The ones closest to the fan. For my small darkroom I just use an inline duct fan (4" model) on the other side of the basement from my darkroom, which sucks air out and exhausts it via a standard dryer vent on the outside of the house. Seems to work fine so far.
Re: Sink-level ventilation
Quote:
Originally Posted by
domaz
This kind of makes sense when you think about. Air is just like water in that it's going to take the easiest route, so if you have one long pipe with holes in it guess which holes in the pipe get the majority of the air flow? The ones closest to the fan. For my small darkroom I just use an inline duct fan (4" model) on the other side of the basement from my darkroom, which sucks air out and exhausts it via a standard dryer vent on the outside of the house. Seems to work fine so far.
Yea, a simple fan somewhere in a wall is what most people probably use which gets the job done in terms of removing air but the issue there is that if the fan is behind you on a wall, in the ceiling, etc, then that means that the system is inherently drawing the air (and any things in it which you don't want in your lungs) up past your face on its way out. Avoiding that is the main point of these sink-surface solutions. If you can get the air (and pollutants) off the surface of the sink and into the vent system without it having to travel past your face, then you have a much more effective system with respect to avoiding inhalation of fumes and particulates.
Re: Sink-level ventilation
Quote:
Originally Posted by
popdoc
This is cool. Where did you find the low profile wall hoods? Thats what I was looking for initially and was going to get one from Edwards Engineering but after a few follow-ups I never heard back and gave up on it. As long as the fan is powerful enough, I think that would be one of the ideal solutions.
Re: Sink-level ventilation
I used a local HVAC company that had a good technical background doing labs, hospitals, etc.
They fabricated it to my specs. The size of the triangular plenum allows for equal distribution of the low pressure (vacuum) across the long opening.
Because I have two sinks, I can turn them on and off mechanically while using one massive remote mounted fan.
Also, I believe we went for an aggressive minimum of 8 changes of room air per hour.
BTW- the inlet air is HEPA filtered…
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