Garage Conversion

[m4cot82]

Hi, thanks for the quick response.

There's a couple of reasons for the ceiling really - 1 is that this way saves a little space height-wise and 2, I'm struggling to see how I would physically nail the plasterboards to the joists on top. Agreed it would be much quicker etc but not sure how I could get up there, particularly as I got to the last piece.

Will add the cross bracing to the plan then - thanks for that!

Thanks

[m4cot82]

Guys,

I have been thinking through the design more, particularly thinking about the construction phase and actually putting this together, and as the room has a very similar width to height, the usual method of - creating the inside-out frames on the floor, adding plasterboard + insulation and then lifting the wall up from the ground into place - won't be feasible. If I built the whole wall on the floor, theres no room left to get behind it to flip it into position. Hope that makes sense.

Given this, I have attached my SketchUp file for a proposed solution - buiding smaller sections of the long walls and lifting them into place one by one. The design animates to hopefully get this across (I have not yet added the plasterboards and insulation on this SketchUp design just yet as I wanted to see what your thoughts were first).

The only problem I see is where they connect together. Maybe by overlapping plasterboards across sections would solve this, but please do let me know what you think.

Edit - The other thing I have added here are some ideas for flush mounting the speakers, some slots and bass traps (all rendered pink in the file attached). Any feedback on these designs would be great. Again, its tight for space but Im trying to make use of it...

Questions:

1: Will the propsed frame solution work - ie creating sections of walls and joing them up - as in the sketchup file?

2: If so, should I overlap the plasterboards between sections?

3: What do you think of the propsed layout? Space is at a premium here and I'm struggling to come up with a better layout.

4: I would like to flush mount the speakers which you will see in the design (not a finished design just the framework), does this look ok?

5: The bass traps at the back (by the doorway) I intent to do superchunk style - is this ok?

6: Thinking about the slot resonators - the fact that one side has the window and therefore they wont be completely symmetrical, will this be a problem?

7: The existing structure also has lots of air bricks. Do I need to block these air bricks to make the external structure more air-tight?

8: (last one I promise) - I plan to build my internal room with new ceiling joists resting on the internal stud walls. What should do with the existing joists? The existing structure at the moment has a pitched roof (not show in diagram) with ceiling joist running the length of the room (shown in diagram). Do I need to plasterboard them underneath sealing the edges to the existing outer brickwork in order to create an air-tight outer structure? If so, should I fill them with rockwool and also place loft boards on top, or would this make it a 3 leaf system (see image below)? Im trying to think of the best solution to ensure that the existing structure is air-tight before I progress with the inner room. Hope that makes sense.

Regards,
Marc

[m4cot82]

Hate to be impatient but, BUMP...

[m4cot82]

If anyone can help with the following questions that would be great:

1: Will the propsed frame solution work - ie creating sections of walls and joining them up - as in the attached new sketchup file?

2: If so, should I overlap the plasterboards between sections?

3: What do you think of the propsed layout? Space is at a premium here and I'm struggling to come up with a better layout.

4: I would like to flush mount the speakers which you will see in the design (not a finished design just the framework), does this look ok?

5: The bass traps at the back (by the doorway) I intent to do superchunk style - is this ok?

6: Thinking about the slot resonators - the fact that one side has the window and therefore wont be completely symmetrical, will this be a problem?

7: The existing structure also has lots of air bricks. Do I need to block these air bricks to make the external structure more air-tight?

8: (last one I promise) - I plan to build my internal room with new ceiling joists resting on the internal stud walls (see file). What should do with the existing joists? The existing structure at the moment has a pitched roof (not show in file) with ceiling joist running the length of the room (shown in file). Should I need to plasterboard them underneath sealing the edges to the existing outer brickwork in order to create an air-tight outer structure? If so, should I fill them with rockwool and also place loft boards on top, or would this make it a 3 leaf system (see file for example)? Im trying to think of the best solution to ensure that the existing structure is air-tight before I progress with the inner room. Hope that makes sense.

[simo]

Hi Marc

I downloaded your SketchUp but can't open it as I'm still on version 8 (the laptop where SU is installed is still on OSX 10.6.8 and SU vers.13 is not supported unfortunately !).

But even going in the dark without seeing the design, if I understand well your question about splitting the wall in two section and then joining them together, I proposed these 2 ideas on this thread:

http://www.johnlsayers.com/phpBB2/viewt ... =2&t=18242

Joint idea.1_A.jpg

Joint idea.1_B.jpg

Joint idea.2_A.jpg

Joint idea.2_B.jpg

…hopefully they are pertinent here, or, if they're not ... sorry ... but I hope at least they'll give you the inspiration for new ideas

Good luck !


Ciao
Simo

[m4cot82]

Simo,

Thanks for this, I'm liking option 2 a lot, hadn't thought of this! Great stuff.

Thanks again.

[m4cot82]

Ok, I am still waiting for answers from my last post, but will move forward and perhaps focus on a different problem for a little while. Again, I have not started the build yet, so still very much in research mode!

Back on to HVAC: I have had a couple of guys round re air-conditioning and ventilation this week to look at the garage and to suggest ideas. They aren't studio experts at all, just local air-con companies, but one has experience working in a school recording studio environment recently. However, I'm keen to make sure I know what im talking about when requesting quotes etc.

Stuart (or anyone else out there) - Here's where I'm at:

So figure the volume of the room (in cubic meters or cubic feet) multiply by the number of changes per hour, and that's your flow rate: you need a fan that can move that much air per hour. Fans are normally rate as being able to move X-many Cubic Feet per Minute (CFM) of air, so look for fans that can move your amount of air.

I have worked out my inner room volume (L:4.8m x W: 2m x H: 2.3m) = 22m3.
If I go for 5 room changes per hour then I need a fan that can move 22m3 x 5 room changes per hour = 110m3.
With this worked out I can divide by 60 minutes (110m3 x 60 minutes) to work out how much air to be moved per minute = 1.8m3.
So i need a fan that can move 1.8m3 per minute.

But that's not all! Fans only produce their rated air flow in free air, with no duct: put them in a ducted system, and the flow rate drops, depending on how much "static pressure" the system has, which basically means how much it resists the flow of air through it. So you have to calculate that, and find a fan that can move that much air at the estimated static pressure of your ducting system and room. For example, a fan might be rated at 250 CFM, but only be able to move 180 CFM with a static pressure of 0.5". So be careful there: do the math, and get the right fan. If you overload a fan with too much static pressure, it will not only not move enough air, but will be much noisier, use more power, be less efficient, and burn out sooner.

Then, with all that figured out, you need to do the calculations to figure the duct size: you want the air flow speed to be less than 300 feet per second (fps) where it leaves the register. Since you already know how many cubic feet per minute you need, and how many feet per second you need, it is now simple math to find out how many square inches of cross section you need for your ducts.

This is where I'm struggling a little. Here we talk about understanding the static pressure of the system and I assumed this to mean - the resistance caused by using the fan within a ducted system, correct? However, we then talk about later working out the duct size required to achieve the relevant air flow speed, but this confuses me as I thought we had already considered duct size when working out static pressure? Sorry if I sound stupid.

I guess what I am asking is: How do I work out both the required duct size and static pressure in order to choose the relevant fan size/power. What are the sequential steps to working this out?

I'm thinking that one single fan will be enough for my build blowing fresh air into the studio, with just a 'stale-air-out' vent (without a fan) where stale air will be forced out. This system together with a small mini-split air con system. If this sounds ok, I assume the 'stale-air-out' vent route will not require silencers?

Any help would be great.
Regards
Marc

[Soundman2020]

I have worked out my inner room volume (L:4.8m x W: 2m x H: 2.3m) = 22m3.
If I go for 5 room changes per hour then I need a fan that can move 22m3 x 5 room changes per hour = 110m3.
With this worked out I can divide by 60 minutes (110m3 x 60 minutes) to work out how much air to be moved per minute = 1.8m3.
So i need a fan that can move 1.8m3 per minute.

Right. But I'd go for a bit more than that. Maybe 2.5 m3/min.

Here we talk about understanding the static pressure of the system and I assumed this to mean - the resistance caused by using the fan within a ducted system, correct?

Right. It's basically the resistance offered by the entire duct system, which includes the rooms.

However, we then talk about later working out the duct size required to achieve the relevant air flow speed, but this confuses me as I thought we had already considered duct size when working out static pressure?

Size your ducts to get the correct speed for the flow rate that you need. Then based on that, check the tables to see how much static pressure drop that length of that sized duct will produce.

How do I work out both the required duct size and static pressure in order to choose the relevant fan size/power. What are the sequential steps to working this out?

As above: You figure out the dimensions of the duct (cross section) that you will need in order to get your airflow velocity slow enough while still providing the right air flow rate (volume per minute). That's what you do to size your ducts. Then you check to see what static pressure drop you will get for that size of duct, then you look for a fan that can give you the correct flow rate for that static pressure.

I'm thinking that one single fan will be enough for my build blowing fresh air into the studio, with just a 'stale-air-out' vent (without a fan) where stale air will be forced out. This system together with a small mini-split air con system. If this sounds ok, I assume the 'stale-air-out' vent route will not require silencers?

The rest is right, but you'll still need a silencer on the exhaust duct. If not, then the sound in your room will "escape" through the duct and be clearly heard outside, and in addition all sounds on the outside will be conducted back through the duct into your studio. You always need silencers on your ducts, at every place where they pass through a leaf.

- Stuart -