Flooring, Dust Collection and Heating

[Shane Copps]

Folks,

I know these issues have been beat to death here but here, but I have some thoughts and questions.

DC- Basically you want maximum (optimum) flow rate at all tools. If you have to drop size in hose it cuts CFM but does not increase "suction". Does this sound basically true?

I am moving into a house that has a 27x27 "extra house". It was an apartment years ago, but flooded and the floor was taken out. The sewer that flooded it was fixed and plugged but it was left as a dirt floor and and had garage doors put in. It will have approx. 10-12 ft ceilings in it when the floor is put in. Basically I have a blank canvas.

What are your thoughts on putting floor heat in a concrete floor? Is there a better option for a floor? My last shop had concrete floors and I put rubber mats down for comfort and heat. It was comfortable but with the options available, can I do better?

What is an inexpensive way to heat the shop (I like to keep it around 60 degrees) without a lot of expense? Isn't that the proverbial question? No gas is hooked to the shop and we pay extremely high power rates. I am a hobbiest and work in the shop nights and days off so it doesn't need to be working warm all the time, but I don't want to have to heat it up from outside temps every time I want to work. I also think large swings in the temp is hard on tools and blades.

Any thoughts are appreciated
Shane

[Justin Ludwig]

I won't touch on the DC question as I have my own quandaries in that area.

Radiant heat pads can be used to heat a shop. If you install it, make sure you do thorough continuity checks and everything is working before you pore concrete. If it ever fails, you're stuck with a cold floor. I've installed it in new construction homes up to 5000 sq ft and also in just a bathroom under concrete board. You get what you pay for so don't get the cheapest. I haven't messed with it since 2009, so others may have more updated experience. The power consumption of these are supposed to be very good economically but a high initial cost.

Personally, I heat a 40x80 (though I occupy 40x40 of it) shop with 16ft ceilings with a 150k propane heater and a fan set at 10' up blowing down to circulate. If it's continually cold, it cost me $160 a month in propane. But I can work in a shop that's 40F without complaint. My body is a furnace (not a wonderland). A 27x27 would get hot in no time with a propane heater. Mine cost $179, the 100lb bottle cost $100, and the initial propane fill was $92. Winter makes LP prices go ^.

[James Conrad]

Do you have an ample budget for radiant heat? Do you have to follow building codes? And, do you want to work on a concrete floor?

[Shane Copps]

Do you have an ample budget for radiant heat? Do you have to follow building codes? And, do you want to work on a concrete floor?

That is why I'm asking James. I will have to follow codes, I'm not sure what the price of floor heat would be in shop this size, and in my prior shops I haven't had any issues with working on a concrete floor, but if I'm in this one for a few years I would rather do it right now than hate it later.

Thanks
Shane

[Ole Anderson]

DC- Basically you want maximum (optimum) flow rate at all tools. If you have to drop size in hose it cuts CFM but does not increase "suction". Does this sound basically true?

Hey, I'm a glutton for punishment, so I'll take a stab at this one: Actually, it does increase suction. If you measure suction in inches of water column, when you decrease the flow, you move up the fan curve to a higher value for static pressure (suction). Also increased suction is perceived as the increased velocity at the end of the hose. So if the cfm (flow) were to stay constant and the diameter decreases, then the velocity will increase. Now keep in mind, I am answering this at 1:30 am after spending 2.5 hours driving (actually riding as my son did the driving) north in a pending snowstorm to snowmobile 172 miles, only to return the same day after a 3.5 hour drive at the end of the storm. So I am really tired, but too wired to hit the sack right now. Oh, and I had to blow the drive after midnight to get the trailer back up the hill.

[Jim Andrew]

As you are starting from scratch, I'd consider putting down a wood floor. Don't know how high the foundation is off the ground, it would be easiest to put your joists on top of it around the perimeter, and you would have to build piers to support a beam through the center of the building level with the foundation plus a plate. Or if the height of the foundation is too high, maybe just pour a footing around the edges and down the center. Be sure to put down some kind of termite protection. In my new room, I used Bayer termite granules spread on the dirt, and the terminex termite stakes around the exterior of the building. I found some signs of termites as I was cleaning up, so took the opportunity to do something about them. As far as dust systems, the theory is that air can be compressed as it goes through restrictions in your system, and maybe that is possible if you have a 5hp cyclone, but much less so if you have a 2hp system. And as for heat, I like wood heat if you have access to trees. I'd prefer an outside wood furnace, so you don't have a fire inside your wood shop. Saw a outside wood furnace, hot air system for sale at our Orshelyn farm store. Think it was built by US Stove co. Cost of gas and electricity for heat makes a hobby shop prohibitive.

[James Conrad]

If your State is still following the 2009 ICC codes, unless your town or state has exemptions for accessory structures and what they consider habitable space, if you condition the space you must meet the energy codes. If there is existing insulation in the walls and cieling, you won't need to do more then what exists, if there is not then a min. of R20 in the walls and R49 in the cieling unless you have conditioned living space over the shop space, if not and it is attic space then you can reduce to R38 as long as you can extended that R38 over the plates of the walls.

The slab will require a min of R10 under it and extending 4' below grade either inside or outside of the foundation wall or slab perimeter. If you heat the slab R15 is required for the edge insulation.

So, that's the energy code you'll likely need to meet, so I would have conversation with your local code official just to make sure and it will help you budget for the project as rigid insulation runs about $50 a sheet for 2" XPS.

What I would do if I was going to heat the slab would be to use at least 4" of edge insulation and 6" under it. If you don't have an existing boiler, a tankless on demand can meet the needs for radiant heat and your domestic hot water. Here is a good article describing how that setup works, it's a few years old but the principles haven't changed. http://www.jlconline.com/water-heate...er-heater.aspx Cost if you need the boiler will be in the $10-14k range, at least in my area.

If you would prefer a wood floor, install the slab with the edge insulation then put your R10 over the top of the slab, which should have a minimum of a 25psi rating and the Advantech subflooring over that. No need for sleepers. If budget allows get thicker than 3/4 Advantech, usually 7/8 is only a little more cost. It will lay flat and you don't need to screw it down unless you want to. I specifically call for Advantech because its very stable, similar substitutes may look the same but turn into potato chips, warping with moisture changes. Then to heat the space use a Rinnai E38 direct vent furnace and propane fuel, unless you have NG in your area. Non vented propane heat releases moisture, not great for tools, and may not meet code for space conditioning. The slab, insulation and Advantech should run in the $5-6k range, the Rinnai about $1500 plus install. If you don't want the wood and opt not to do radiant I would insulate the slab the same as if I was, it's just a big heat sink after all, and the better insulated it is the more heat it will retain.

[robert morrison]

Considering that you are in MT, I would plan on isulating, regardless what else you do. With an older house, I would assume you have 2 x 4 walls, and little or no insulation. If you do fiberglass in the walls, you would still need to do 1"-1.5" of rigid insulatin board on the inside to get up to R20 range. Insulate under and on the outside of the slab. The old windows are probably not the best for keeping heat in. If you want to spend the $ for double or triple pane window great, if not take out the windows and frame them in.

I would go with radiant heat in the floor slab. While you are putting in tubing, you may want to plan for a couple outlets coming up out of the floor via conduit. Your not talking a large space, a hot water heater would be more than sufficent to heat the water in the tubing.

A single zone with one manuall mixing valve would work fine. If you wanted to get a little more elaborate you could make it into two zones with the 2nd zone being in the area of a paint room, if your planing on one. Having two zones with separate circulator pumps for each gives you a bit of a safety net, in case one circ pump quits, and you don't notice for a period of time.

With the radiant heat you could set it for 58- 60* and be plenty comfortable with warm feet. Put foam mats down around your workbench and anywhere you stand still for an extended period of time. This will still leave 90% of the floor exposed to heat the room.

Double french style steel doors would be a good combination to provide insulation, and a way to get wide things in and out of the building.

[Michael W. Clark]

On the DC question, it depends on your point of view and your definition of "suction". If "suction" means static pressure, then Ole is correct, especially if you are measuring this at the collector or fan inlet. When you neck down, you increase resistance, which causes the fan to move up its curve. The generates less flow, but more static pressure.

If you are measuring at the hood face or at the source, then the "suction" actually goes down because the CFM went down. Also, the dust capture went down because the CFM went down.

General rule is to avoid necking down if possible, but a lot of machines come with 4" connections. Many times, the machines (and you) benefit from enlarging the port.

Mike

[Shane Copps]

All,

This gives me a bunch to think about (probably more than my little brain can digest). I appreciate everyone's input.

I have a little time before we move and do something with the shop floor. I am for sure going to insulate the floor weather or not I put heat in it. I am probably going to still go with the concrete so if I need to I can pull vehicles, atvs etc in. We will have a separate garage and carport so that shouldn't happen often.

Still trying to figure out the DC and how to heat the shop. My auction-bought DC is buried in storage until we move. As is all of my shop


We pay the highest $/KW and some of the highest propane around. The electric Co-op guys will even tell you that to your face as they are in the middle of some lawsuit and trying to keep a war-chest full.

Thanks
Shane