Using your laser cutter/engraver inside your homeHP Persson
Many of us, including me have a machine inside the home.
I have a bunch of machine but at my home i have my custom K40D at the moment, and with kids in the home and close neighbors i need to think about the smoke and smell from my machine.
In this article i will show some examples and tips & tricks how to make your laser use safer in your home.
First up, almost the most important is to seal up your machine and have a proper working exhaust in the machine.
You can read a more detailed article about sealing your machine and exhaust here
Location location location
Having a room where you use the machine is almost a must.
You can have it in a bigger room where you have other stuff, but i would not recommend kitchen, bedroom or where you have your TV and couch.
I use a smaller room, 6×4 meters with a window and ventilation.
Step 1 – Seal your room
Make sure the room you have the machine in are sealed, no gaps or holes going to other rooms.
If you have ventilation between the rooms, make sure they are covered or closed.
Buy rubber strips and add to the edges of your door so its sealed towards the door frame. Aim for 95% seal, so there is a small opening in a corner or similar for air intake. 2-3cm is enough with a hight of 0.5 to 1cm.
Step 2 – Negative pressure in your room
Removing air (not all, just so you get a lower pressure) from your room will keep the rest of your house safe from fumes or smoke escaping from the laser machine.
You can do this in several ways.
Solution 1: Adding a exhaust fan in the window or wall to suck air out from the room. The gap in the door seal will be the natural intake for new air.
Solution 2: Adding a fan in the door or wall pushing air in to the room from the house, and using a exhaust in the window or wall. Just make sure the intake fan has lower flow than the exhaust.
Both solutions will do the same, but adding both intake and exhaust for the room will make it easier on the exhaust and no need for big fans to do this.
The exhaust from the laser machine can be used for this – or you can add a extra exhaust just to keep the room under negative pressure.
With the negative pressure, any leaks, smell or fumes from the machine will be pushed out as the house has higher pressure than your room has. It will be pulled to the other side of the pressure difference (other side of impeller in the fan).
A word on flow rates
This depends so much of the room you are in.
My room is 6×4 meters and have a window with a ventilation door on the side, and a door in to the room in the other side of the window. Your room might look different.
I use solution 1 with only a exhaust, and it´s inside the machine – the machine is set up with both intake and exhaust fans – see the article linked in the top.
Fans used for exhaust is 187m3/h or roughly 110CFM – but it has pretty good static pressure, and my door is sealed with rubber strips you can see a picture of above.
I do only cut acrylic in my machine, if you do a lot of wood cutting or engraving i would suggest at least 3-500m3/h or even more.
What you never should do
– Never overpressure the room by pushing air in and not taking anything out.
This will cause any smell spreading to the rest of the house.
– Never use open air filters and dumping the air inside your house, ever.
If you use any kind of filters, make sure the air can pass through it – and then out.
Here is a example of filter you should never ever use with your laser machine. It´s straight up dangerous if you use it to dump the air inside your room.
Always make sure the filter has two holes – inlet and outlet so the left over air after filtration can be dumped outside. Because these filters will not remove 100% of the dangerous fumes and particles – it will only lower the smell and some of the visible smoke.
Make sure you connect it in this order: Laser machine -> filter -> fan -> window
Having the fan at the window is the only solution – never put the filter after the fan, this will lower the efficiency by half or more.