Pole Barn Heating Vs. Ventilation Question

[Vincenthdfan]

Hello all...I live in Western Washington State.

I have a 30' x 42' x 14' pole barn that has the plastic encapsulated insulation on the entire ceiling as well as the walls.

I also have two insulated roll up doors.

I am heating it with a thermostatically controlled 30 foot natural gas 80,000 BTU Radiant Tube Heater right down the center, set at about 12 feet off the floor.

My questions are...

I have two gable end louvered vents just under the peaks (peaks are 19 feet) of both ends of my building.

Should I be closing them off to help retain the heat in the dead of winter (its 18 degrees outside right now!).

Would closing them off create a non-ventilated moisture encapsulated building when the winter temps get back to a more seasonal norm than the deep freeze we're currently having?

Thanks for any help you can provide.

 

[BlackTalon]

I'm a little confused. Are the vents above or below the roof insulation? They would be very counterproductive WRT interior comfort if they were below the insulation.

 

[Vincenthdfan]

They're out in the open.

They're framed into the structure and surrounded by insulation on all 4 sides.

Several inches below the rafters, built into the wall.

 

[BlackTalon]

They definitely are working against heating the garage and should be closed off. maybe you can cut some rigid insulation and use that to cover the openings for the winter. If you don't use AC in the summer, you can open the louvers back up again and let them vent out the hot air that builds up.

I'm assuming the gas heater is vented out through the wall or roof though. That would be critical.

 

[Vincenthdfan]

Yes, the exhaust is vented outside and the heater is kept at a minimum level to ward off freezing during cold spells.

My concern about covering the vents is, will that create a moisture laden environment because of no fresh air exchange?

 

[Highbeam]

A valid concern but what is your source of moisture? Do you have a vent in your house?

 

[Vincenthdfan]

Well as you know, here in the Northwest we have quite the humidity in the winter time with all the rain as well as some pretty radical temperature swings when we go from cold spells back to average, wet temps, etc...

My old pole barn that I lost in a divorce years ago sweat like a big dog during the winter and would literally rain from the ceiling at times and would produce mold on my service manuals, etc.

It didn't have vents on it and it wasn't heated at the time of the condensation issues.

Once I put wood heat in it, it obviously dried things out pretty well if only periodically.

When I built this shop, I had it fully insulated and had gable vents put on each end.

I also bought and installed the 80,000 BTU radiant heat tube so I cant keep it comfy during the winter.

With this recent cold snap, its literally been 18 degrees outside in the mornings for many days in a row.

Im keeping the heat at 45 degrees via thermostat in the shop.

I hate the thought of venting the heat right out those louvers all night long, thus my question regarding blocking the vents.

I talked to the Permabilt folks tonight that built the building and they said absolutely keep it vented to preclude moisture buildup.

I guess once again, Im overthinking this?

 

[BlackTalon]

can you access the vents to close them off when you will have the heater running? 80,000 BTUs blowing right out through the endwalls doesn't sound like an economical way to heat.

 

[Vincenthdfan]

Its not a "blower" type heater...its a radiant tube type heater.

It heats the objects in the room like the sun does and it works very well.

Even so, I'm with you, it seems counterproductive at 18 degrees to have an open vent on each end of the building.

 

[Shop Specialties]

The radiant heater heats objects not the air. Close off the vents and it will sweat just like your last building.