Paint booth

David Sutton_6

I have a custermr who has a paint booth that needs heat. all they have in the Bldg are modine heaters any good and practicale ideas out there?? thanks...David

Mike T., Swampeast MO

This came up recently here and concensus was that good old iron radiators work fine and have no problem with huge volumes of overspray. Of course you'd need a hot water source so such might not be practical for your application. I kind of hate to mention that "water heaters" of both the tank and tankless variety (with appropriate controls/safeties added of course) are frequently used for small loads. May not be legal in all locations.

Search for "paint booth" and you should find the thread. Believe it's around a month old.

Larry (from OSHA)

Hello David

Some considerations that your customer should take into account would be the OSHA requirements for not only spray fininshing found under 1910.107, but the ventilation requirements under 1910.94. In part, the requirements state:

(iv) [a] Means for heating make-up air to any spray booth or room, before or at the time spraying is normally performed, shall be provided in all places where the outdoor temperature may be expected to remain below 55 oF. for appreciable periods of time during the operation of the booth except where adequate and safe means of radiant heating for all operating personnel affected is provided. The replacement air during the heating seasons shall be maintained at not less than 65 oF. at the point of entry into the spray booth or spray room. When otherwise unheated make-up air would be at a temperature of more than 10 oF. below room temperature, its temperature shall be regulated as provided in section 3.6.3 of ANSI Z9.2-1960.
[b] As an alternative to an air replacement system complying with the preceding section, general heating of the building in which the spray room or booth is located may be employed provided that all occupied parts of the building are maintained at not less than 65 oF. when the exhaust system is in operation or the general heating system supplemented by other sources of heat may be employed to meet this requirement.
[c] No means of heating make-up air shall be located in a spray booth.
[d] Where make-up air is heated by coal or oil, the products of combustion shall not be allowed to mix with the make-up air, and the products of combustion shall be conducted outside the building through a flue terminating at a point remote from all points where make-up air enters the building.
[e] Where make-up air is heated by gas, and the products of combustion are not mixed with the make-up air but are conducted through an independent flue to a point outside the building remote from all points where make-up air enters the building, it is not necessary to comply with paragraph (c)(7)(iv)(f) of this section.
[f] Where make-up air to any manually operated spray booth or room is heated by gas and the products of combustion are allowed to mix with the supply air, the following precautions must be taken:
[1] The gas must have a distinctive and strong enough odor to warn workmen in a spray booth or room of its presence if in an unburned state in the make-up air.
[2] The maximum rate of gas supply to the make-up air heater burners must not exceed that which would yield in excess of 200 p.p.m. (parts per million) of carbon monoxide or 2,000 p.p.m. of total combustible gases in the mixture if the unburned gas upon the occurrence of flame failure were mixed with all of the make-up air supplied.
[3] A fan must be provided to deliver the mixture of heated air and products of combustion from the plenum chamber housing the gas burners to the spray booth or room.

In 1910.107 there is a requirement to keep things clean and free of redidue buildup.

(2) Cleaning. All spraying areas shall be kept as free from the accumulation of deposits of combustible residues as practical, with cleaning conducted daily if necessary. Scrapers, spuds, or other such tools used for cleaning purposes shall be of nonsparking material.


Very long winded, I'm sorry. But the jist of all this is to provide adequate makeup air and to prevent the accumulation of fuels.

Also, as you see, the allowance for radiant heat is provided, but again you need to prevent residue buildups. I would think that heated makeup air would be easiest and most practical.

(my 2 cents worth)

The regs can be found at:

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9734

and

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9753

I hope this helps.

Weezbo

Thats got to be the most complete run down you Ever

though you would hear *~/:)

Thats our OSHA Guy LARRY Him Good

Larry Go with the seperate storage containment fields for paints

David Sutton_6

just what i needed....

Thank you very much Larry, sure great having you here at the wall.

Mike T., Swampeast MO

Larry:

I've read, re-read and re-re-read that reply.

A cast iron radiator conforms to letter and spirit as long as the heat source for that radiator is outside the booth.

Even OHSHA understands that a spray booth is an "unusual" circumstance requiring "special" circumstances and protections on the part of the person spraying. Much of that reply [seems] to require truly unachievable engineering unless radiant heat is utilized.

tim smith

paint booth heater

> I have a custermr who has a paint booth that

> needs heat. all they have in the Bldg are modine

> heaters any good and practicale ideas out there??

> thanks...David

tim smith

paint booth heater

good ole Reznor makeup air heater on roof, supply 100 % makeup air with same volume exhaust. Filtered of course. This is what we have in current body shops.

Larry (from OSHA)

Mike

come on Mike. Are you saying that OSHA regs are not written in plain English? I think the path that the writer of the reg was traveling down was the thought of having make up air to offset the exhaust and the easiest way to heat the booth was by heating the make up air. All the rest basically says don't use a camp fire in the booth to warm things up. The use of radiant, be it floors or standing iron, I would think would work nicely, but with radiators, the issue of overspray must be addressed. I have seen many a booth that looked as though they never had been cleaned and it can become a real fire hazard depending on the variety of paints that build up on the surfaces. Of course, most booth fires are in the middle of the night from spontanious combustion, so employee exposure to fire hazards would be slim to none.