Concept2 HEPA Air Purifier

[robnotyou]

Clean air is good, and the Concept2 rower incorporates a fan.
Could the rowing action be used to clean the room's air, by putting a HEPA filter (captures pollen, dirt, dust) over the air inlet?

[jamesg]

I have a filter over the air inlet. Main reason is to drop drag factor as low as possible (80-90 with damper 10) so that even my weak pull takes less than a second. It certainly keeps the fan clean.

[Ombrax]

Speaking of air purifiers, there's an interesting discussion at the link below (in the "Comments" section) about whether an electric fan pulling air through some media will draw more or less current if the intake is obstructed.

I'm not familiar with electric motors and how much current the draw, but I do know that it's easier to pull the C2 erg handle when the intake is closed...

https://tombuildsstuff.blogspot.com/201 ... ifier.html

[jamesg]

Basic engineering for pumps and fans: no flow no power. Applies to us too, if we provide the power.

[robnotyou]

The idea of a HEPA filter is that it can filter out (tiny) particles, _without_ greatly restricting the flow of air.

I'm hoping that I can keep the Concept2 on my current drag factor of 130, by adjusting the inlet lever.
(Just as I do when I attach the C Breeze in Summer, to direct a cooling airflow at me.)

I've acquired a filter of a suitable size, so I'll be figuring out a way to attach it next week.
I'll post the results!

[robnotyou]

Proof Of Concept

[Filter Frame][https://notyou.co.uk/images/concept2/FilterFrame.jpg]
A bit of cardboard engineering, and we have a filter frame.

[Proof Of Concept][https://notyou.co.uk/images/concept2/ProofOfConcept.jpg]
For the Proof Of Concept, I'll just strap it on for now... no changes to the Concept2 at this stage.

Well, it seems to work.
I'll see how I get on with tomorrow morning's row!

[robnotyou]

Aaaand... I've finally figured out how to post images...

Filter Frame:


Proof of Concept:

[robnotyou]

So far so good...

* The filter stayed in place while rowing
* There was a good flow of air...
* ...which was very clean!

The drag factor is a bit lower than I would like (97).
To increase that, I'd have to make the air inlet larger, and I'm not (yet) ready to cut the Concept2.

I'll try it for a month, and see what effect it has on my allergies.

[Tsnor]

So far so good...

* The filter stayed in place while rowing
* There was a good flow of air...
* ...which was very clean!

The drag factor is a bit lower than I would like (97).
To increase that, I'd have to make the air inlet larger, and I'm not (yet) ready to cut the Concept2.

I'll try it for a month, and see what effect it has on my allergies.

Assume you are doing this for fun, because a good hepa air filter in the room will have more effective air flow.

Some suggestions:

Try building a shape that allows more filter area. Problem is not the inlet to the C2, it's the filter covered inlet. Suggest a cube with filter material on 4 or 5 sides and the 6th side connected to the c2 rower. That can give you 5X to 10X the filter surface area. Any large box will work. Cutting the C2 seems a bad idea, but replacement parts are available if you try it and it goes poorly.

You will get better results with different filter media. Look at the airflow for the hepa furnace filters, they are not all the same. Look at deep pleated furnace filters (say 4" depth). Look at the hepa filter cylinders used by honeywell in their air purifiers.

If you stay with flat filter media look at putting the filter media on the OUTPUT side of the C2. The mesh screen on the outside of the C2 flywheel housing comes off. See youtube for videos how to clean flywheel screen for details, it's simple. See if there is enough clearance to line the inside of the mesh with filter media. This would give you a larger area for the filter media so less back pressure. Fan may work better pushing thru the media rather than pulling (pure guess).

Glad you are having fun with design and with your rowing. win/win. And for some people exercise can reduce harmful impact of allergies. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6603979/ Hopefully you are one of the people who gets benefit.

[robnotyou]

@Tsnor, what a great post!

As you spotted, this is just for fun, but it is actually working quite well.
I can definitely notice an improvement in the air quality while rowing, and as @jamesg said, it should keep the fan clean.

I think it's weakness, as an air purifier, will always be that it is only running for a short time each day (20 minutes, in my case).

I have some ideas for version 2, making use of the full filter area (rather than just part of it), but I probably won't go to the expense/complexity of a cube design.