Insulation around new IC recessed lighting/condensation

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Old 04-08-17, 10:21 AM
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Insulation around new IC recessed lighting/condensation

Here's the deal.

We are replacing old non-IC cans in our kitchen. They were not put in properly. No 3 inch dam and no cap over the cans. The batt insulation was just put back over the cans creating a possible fire hazard. The new lights will be LED, IC, air tight cans with the gasket to prevent air leakage into the attic.

The question is can we just lay the batt insulation over these new lights? The electricians I've talked to don't really deal with insulation and don't seem to think condensation will be a problem.

I'd add more insulation myself afterwards, but I can't. The attics in this area are really tight and have to be crawled through. I'm just too old and fat to do it anymore.

To be clear, I haven't seen any type of water problem on the ceiling even with our old non-IC lights. I live in Southern California where it's hot in the summer but doesn't get very cold in the winter. We have soffit vents and turbines on the roof for venting.

Any help or advice in this matter will be greatly appreciated. Thanks!!
 
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Old 04-08-17, 11:30 AM
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IC means Insulation contact. You can bury them in all the insulation you want. They have safety overload "sensor" if the can gets too hot so as not to cause a fire hazard.
 
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Old 04-08-17, 11:52 AM
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Ah, I guess I didn't make my question clear. I understand IC can touch insulation. What I'm wondering is - would just laying the batt insulation over the cans be sufficient or do I need to add insulation/pack it around the can? The electrician said the can would be air tight and didn't seem worried about adding more to stop condensation.
 
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Old 04-08-17, 01:22 PM
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Normally what ever the attic is insulated with is fine,never have seen any additional around recessed cans.
Geo
 
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Old 04-09-17, 10:05 AM
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Okay, I guess since they are airtight (no moisture escaping from kitchen to attic) and LED (less heat being generated) that condensation won't be an issue and I can just cover them up with the existing batt insulation instead of packing new insulation around them..

Haha. If I got this wrong, please correct me. Thanks again for the help.
 
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Old 04-09-17, 10:24 AM
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In Southern Cal I assume you are predominantly air conditioning as opposed to heating. In that case your ceiling air doesn't really leak into the attic. When the house is cooler than the outside the heavier cool air moves down and leaks out the lower portions of the house while warn attic air seeps in from above to replace it. The term isn't exactly correct but they refer to this as reverse stack effect.

Once you install air sealed cans (and they are rarely perfectly sealed) you have minimizes the hot attic as the source. But insulation has little to do with air leakage. Its role is to isolate the ceiling and those cans from the heat above and for that purpose more insulation is better.

If you play with a dew point calculator your risks of any condensation are very low despite outside humidity. I played and could not find a range that concerned me. A heating climate, yes, but I suspect you use very little heat.

Personally, I would take advantage of the access and install as much as I could without blocking your ventilation.

Bud
 
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Old 04-10-17, 10:16 AM
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Thanks Bud. So from what you wrote, I understand that the cans won't get cold enough to cause condensation when the attic is hot and humid. That's great news.

In the winter, would the warmer air from the house (we go for about 70 degrees) cause any problems (the coldest days of the year are in the low 40s degrees at night). I guess the real question here is for all the attic, not just around the cans, but does warm air cause condensation in a cold attic?

Thanks.
 
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Old 04-10-17, 11:04 AM
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The air in your attic is essentially outside air, whether it is 100 at 90% RH or 140 at 30% RH it has the same moisture content (dew point). As for your ceiling or those cans becoming a condensation issue consider your windows they are cooler than your ceiling with less r-value and you don't see condensation dripping down the outside.

As for your winter conditions you are far from what we deal with in the north. Reasonable air sealing to keep that warm air from flowing into the attic along with reasonable insulation and good ventilation and you will have no problems. You don't want large leaks or bath exhaust fans delivering excess amounts or moisture into your attic and you do want traditional amounts of ventilation.

Bud
 
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