Winters coming, how to replenish shop heat quickly?

[drodda]

We spray clear coat in one section of the shop. Of course we have a vent fan to exhaust the fumes from the room during spraying. However living in a cold climate, we find that during the coarse of spraying we tend to lower the room temperature quite a bit while the exhaust fan is running.

I am looking at a way to replenish the room heat witout blowing dust all over everything we just clear coated. Any good economical ideas? I know what a makeup unit is, however we don't have the gas supply to run one on the shop. We have a forced air furnace in the other part of the shop. This keeps it warm except during the spray times. I am looking at a way to safely heat the air in this room without breaking the bank. We have looked at base board heat but I don't know that the recovery time is fast enough.



Any help in this area would be greatly appreciated. I am aware of the safety issues, so no need to post horror stories in this thread.

[magic]

I use heavy plastic sheets to make a "Clean room" and 500 watt lights. Between those two, you can warm up and area and diminish the humidity.

With the new formulas of Lacquers I've learned NOT to use reducer but instead use retarder.

[Gary Campbell]

Dave..
Your only option will be an air makeup unit. How economical it is will be up to your inginuity.

If you promise not to ask me how I know, I can tell you that a sealed combustion natural gas, "Modine type" heater doesnt work due to the fact that the paint particles stick to the stainless heat tubes. When the tubes heat up the dried paint burns off and is ejected, flaming, into the paint room! Filters just slowed the process. Good Luck.
Gary

[drodda]

I have actually walled off an area of 22 ft wide by 42 feet long. This is the area where we try to keep it cleaner that the rest of the shop. We have a garage door 9ft x 9ft and a walk in door between the wood area and this area. The forced air furnace is in the wood area of the shop. Right now when we turn on the fan in the spray room it actually suck air from the wood shop area. I would like to stop this by allowing that room to warm itself without help from the other part.

Gary,

That sort of seemed like a horror story, however I won't ask how you know this? An air makeup unit requires too much gas. My shop is fed off my house meter. The shop is 100 feet behind the house in a residential part of town. I've been told that I would have to install a high pressure line in order to get the gas required. This poses two problems. First atracting attention to my shop by nosy neighbors. second cost of the unit and the gas install far exceeds my current budget. We have gotten by for five years now with the way we do it, however I am wanting to try something different if possible. I spray mostly conversion varnish and really don't want to meet Allah anytime soon. We had planned on being in a new shop by now however the economic situation currenly warrants staying put for awhile.

Thanks for the help.

-D

[fmihm]

You might consider radiant heating, such as from a quartz heater. From a Wiki page:
"This heat directly warms people and objects in the room, rather than warming the air. This style of heater is particularly useful in areas which unheated air flows through. They are also ideal for basements and garages where spot heating is desired."

From another Web page:
"The high-efficiency heat transfer of radiant systems results in even, consistent heating at far lower energy costs than with conventional systems."

Here is a Wiki article about radiant heating:
http://en.wikipedia.org/wiki/Underfloor_heating

[donchandler]

Use tube type IR heaters if you can. I have them in my shop and we can open the 14' door and load a truck, close the door and it is warm again very quickly. Check this out.
http://www.reverberray.com/theory.html

[Call-Tech]

I don't know how often you need this make up heat, but a propane furnace like those used in motorhomes might be an option. You could mount it on the wall in that area of your shop and run it off 20 or 30 lbs tanks stored outside and not draw unwanted attention. But if this is a problem that requires it to run all winter, then you would be changing tanks every few days and that would kill your budget real quick.

By the way, I do not mean to put furnace in spray area... you do not want flame anywhere you are spraying. you can use ducts to put heated air anywhere you want it, without having flame near spray area. There are also electric baseboard heaters available from Grainger that work very well, I have a few in my basement. They run on 220v and are surprisingly efficient.

[chiloquinruss]

'the fan in the spray room it actually suck air from the wood shop area'. How about looking for a way to seal up the partition between the wood shop and the paint shop? Also how about a vent at the other end of the paint shop so that there is less pressure to suck air from the wood shop? Quartz heat is good but I don't know how much / many you would need for that large a space. BTW I have NO heat yet in my new shop soooooo!
Russ

[drodda]

The air coming from the wood shop is intentional as the room can't exhaust the fumes if no air is coming in. The heated air in the woodshop is used to replenish the air leaving through the fan in the spray room. I open the door to allow this to happen. The room is totally sealed off from the wood room now unless you leave the door cracked.

As for a vent, it does no good to bring sub-zero air into the spray room from outside. This would mess with my finish dramatically.

I realize those of you living in the south are scratching your heads to even consider the problem.

[chiloquinruss]

Dave - 'The heated air in the woodshop is used to replenish the air leaving through the fan in the spray room.' Thanks for the explanation, as I said I'm doing my new shop as I write this post and I also will have to experience the cold issues. It is currently 28f outside right now! I appreciate your update to the info, thank you. Russ

[gene]

Has anyone used Charcoal air filters to take the fumes out of the air? I have a 15x15 paint room in a corner of my shop and for now i vent the fumes outside , and filter the air going into the paint room. I am planning an expansion soon and will incoorperate a binks spray filter system into the new paint room, I plan on trying the charcoal filters as soon as i get the new room up and going , with a smaller fresh air intake and a matching exaust ( cfm) fan system. I hope this makes the shop stay warmer by keeping the warm air inside

[Call-Tech]

You could create a paint room inside your shop and exhaust your painted air into shop through series of charcoal & filters and thereby not send heated air outside and not cool off your shop. I think many paint rooms do this. I'm sure there are filtration systems available that have same properties as our VOC Safe Paint Respirators where exiting air is safe.

Realistically we should all be making sure the air we are venting is safe. We don't want to vent chemically contaminated air outside either.

Here is a link to legacy garage where a guy built paintroom out of pvc pipe and plastic. He is venting outside, but same design could be modified and filtered to vent inside. I was just impressed with the simplicity of his setup.

http://legacygarage.com/new_page_1.htm

[jhicks]

Great post. I am also looking at moving back to my old shop, setting up a spray booth and considering the same issues. The one question I have for posters here is the exhaust fan question.
Aren't you supposed to make sure your fan and heater has no potential for sparks/flames? Like there are special purpose built exhaust fans made so the atomized chemistry being exhausted doesn't ignite?
I have an electric heater and wonder about the heating elements as well.
Maybe the filters insure the chemistry never reaches the motor but the flame/combustion concern is far greater to me than the make up unit and temporary heat loss. At least for the imediate set up.
Any feedback on proper motor/exhaust fan and electric heater concern options are appreciated.

I have a rather large 24" diameter blade exhaust fan in the shop mounted at the roof peak to draw airborne dust and bring in fresh air during summer but am wondering if that's a safe set up for solvent based finish exhaust to the outdoors even if I add filters in the booth?
Thanks.
Legagy garage and others seem to use conventonal motors and blowers or fans with out mentioning the flame out concern.

[drodda]

Jerry,

Right now I have been using a shop fan in an open window for exhaust. However I do have a 36" explosion proof fan here in the shop waiting to be installed. I have used this fan system with no filters for some time now. Although I am very aware of the risk a spark might make in the shop.

Yes it's true I run with scissors and don't always chew my food propperly. I guess I have always been a risk taker.

I bought a 9 ft x 9ft open spray booth that came with the fan from a shop closing down. The motor needs to be changed to a single phase in order to work in my shop. This fan is going to exhaust air much faster than my current fan. This is the reason I am trying to replace the warm air with more warm air without spending the 5-10 thousand on a makeup unit.

As for the electric heat you mention, I am not comfortable having a red glowing heating element in the spray area. I don't think I am that brave. Perhaps if the air coming in the back of the electric furnace was from an outside filtered clean source it might work as long as the fan always stays on while fumes are present?

[bcondon]

Dave,

have you looked at the system that are used in tight houses that effectively transfer the heat from the outgoing lines and replenish the heat into the incoming lines? I know they are expensive (around $500) but was looking at them because we have foam insulation (a very tight house) and the cooking smells can build up.

The unit exhausts air but put the air through a heat exchanger to heat the air that is being imported in from the outside.

Bob Condon

[drodda]

Bob,

Any links to this kind of system?

[harold_weber]

Dave, try Googling "Heat Recovery Ventilator", or call a HVAC shop. Your concern will be fouling the room exhaust air side of the device with paint, so you will need to filter that air. These heat exchangers would also work in the summer months to save on air conditioning costs.

[rnels]

Dave,

Have radiant in-floor heat (like Frank pointed out above) throughout the house with the shop as a separate zone (each zone has it's own thermometer). Located in Northern Minnesota it is used quite abit up here. Boiler is located in another part of the house so there is no ignition source from the furnace. Might not be for an existing shop (however it could be added in a subfloor) but if you might be designing a new one I would consider this. Floor stays warm even with garage door open for a time and reheats quite quickly and there are no fans blowing air and dust around. Here is a link to one manufacturer : http://www.uponor-usa.com/Header/Systems/Heating/Overview.aspx

Randy

[bcondon]

Very basic information on heat exchangers

http://www.airexchangers.info/air_exchanger_faq.html


The heat exchanger has 4 tubes coming from in.


1. outside air (input air) -> exchanger -> Inside air INPUT 3.
2. outside air (EXHAUST) <- exchanger <- Inside Air Exhaust 4.


As the information above states, the air coming in will be 80% heat retained
or 20% loss (which means colder). What if you had the exhaust come from the paint room
but have the input air go into the wood shop and have a good filter between the wood room and the
paint room to catch dust etc? this way, you air supply is a consistent temperature but you are
not completely dumping the heat content outdoors.

Another thought is to have a filter BOX between the wood shop and paint room. The fresh air would go into the box with the woodshop air, mix and gain some heat back.... another addition to this could be a small fan that forces air from the wood shop into the filter box (to mix) with the cooler input air from the outside.

I am very interested in this discussion because I will need to set up a paint room very soon and will have the same issues.

Thanks
Bob



I think the units are around $500 which is not inexpensive...

Here is a units that I found online :

http://www.getcozy.com/airtoairex.html

[drodda]

Bob,

The only problem I see in the exchangers is that they are relatively small. My exhaust fan is 36" now. These all look to be 4 to 6 inches in size. I don't know for a fact but I am guessing that an exchanger large enough to vent a spray room would be out of my price range now.