Comments on: New Research Facility to Test Home Energy Improvements http://blog.floridaenergycenter.org/echronicle/2011/01/new-research-facility-to-test-home-energy-improvements/ A Newsletter of the Florida Solar Energy Center Thu, 25 Apr 2013 13:00:35 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Sherri Shields http://blog.floridaenergycenter.org/echronicle/2011/01/new-research-facility-to-test-home-energy-improvements/comment-page-1/#comment-2914 Sherri Shields Thu, 14 Apr 2011 12:26:15 +0000 http://blog.floridaenergycenter.org/echronicle/?p=1288#comment-2914 Mr. Roberts: According to Danny Parker, author of the publication you refer to, in order to do what you want to do (drying the attic with sealed attic construction) you would need a special controller, which is not on the market. Essentially, at the Nightcool facility, we ventilate the attic when the attic dew point is higher than the outdoor dew point. (Can't use relative humidity; must use dewpoint). We use a datalogger to make the decision to vent or not vent the attic every five minutes. * If attic dewpoint is > outdoor dewpoint, then turn on vent fan * Otherwise don't vent This could be done with two reliable hygrometers (we use Vaisala humidity transmitters) and with a microcontroller and a D.C. powered attic vent fan. It doesn't exist, but it could exist and someone with electronics skills could accomplish this. Mr. Roberts:
According to Danny Parker, author of the publication you refer to, in order to do what you want to do (drying the attic with sealed attic construction) you would need a special controller, which is not on the market.

Essentially, at the Nightcool facility, we ventilate the attic when the attic dew point is higher than the outdoor dew point. (Can’t use relative humidity; must use dewpoint). We use a datalogger to make the decision to vent or not vent the attic every five minutes.

* If attic dewpoint is > outdoor dewpoint, then turn on vent fan
* Otherwise don’t vent

This could be done with two reliable hygrometers (we use Vaisala humidity transmitters) and with a microcontroller and a D.C. powered attic vent fan.

It doesn’t exist, but it could exist and someone with electronics skills could accomplish this.

]]> By: Hank Roberts http://blog.floridaenergycenter.org/echronicle/2011/01/new-research-facility-to-test-home-energy-improvements/comment-page-1/#comment-2897 Hank Roberts Sun, 27 Mar 2011 01:12:14 +0000 http://blog.floridaenergycenter.org/echronicle/?p=1288#comment-2897 Hi, I'm curious if you can post any news about this project from a couple of years back: ------- These folks at UCF.EDU back in 2008 wrote about and built a "cool white roof" intentionally to collect moisture from inside the house. We got the same effect reroofing our 1920s house with a cool white roof, but it took us by surprise, we didn't know it would happen -- so we're looking for info on building the smart computer controlled ventilation system described in the excerpt below. So far I haven't found any help. I'd really like to get details enough to build it. This is from 2008 and describes the problem as an opportunity, being tested: http://fsec.ucf.edu/en/publications/pdf/FSEC-CR-1771-08.pdf ------excerpt follows----- .... with no way for the moisture to be removed from the building there is only a temporary benefit from adding the desiccant packs unless the attic is ventilated. Therefore four watt DC ventilation fans were added to the otherwise sealed NightCool attic - one for supply ventilation feeding in 40 cfm (19 L/s) of outside air from the south east side soffit and the other exhausting warm moist air from the attic western side ridge and exhausting that air out of the north soffit. In January 2008 we began controlling the experimental facility attic ventilation based on the difference in the attic to outdoor absolute humidity. In this mode of operation, the sun's heat warms the attic and dries the desiccants activating the attic ventilation fans and thereby removing moisture. The status of the fans is determined every five minutes. If the exterior humidity is lower than that inside, the ventilation fans are activated. Otherwise they remain unpowered. During the night the ventilation ends and the desiccant reabsorbs moisture from the space during NightCool operation...." Hi, I’m curious if you can post any news about this project from a couple of years back:
——-
These folks at UCF.EDU back in 2008 wrote about and built a “cool white roof” intentionally to collect moisture from inside the house.

We got the same effect reroofing our 1920s house with a cool white roof, but it took us by surprise, we didn’t know it would happen — so we’re looking for info on building the smart computer controlled ventilation system described in the excerpt below.

So far I haven’t found any help. I’d really like to get details enough to build it.

This is from 2008 and describes the problem as an opportunity, being tested:

http://fsec.ucf.edu/en/publications/pdf/FSEC-CR-1771-08.pdf

——excerpt follows—–

…. with no way for the moisture to be removed from the building there is only a temporary benefit from adding the desiccant packs unless the attic is ventilated.

Therefore four watt DC ventilation fans were added to the otherwise sealed NightCool attic – one for supply ventilation feeding in 40 cfm (19 L/s) of outside air from the south east side soffit and the other exhausting warm moist air from the attic western side ridge and exhausting that air out of the north soffit.

In January 2008 we began controlling the experimental facility attic ventilation based on the difference in the attic to outdoor absolute humidity. In this mode of operation, the sun’s heat warms the attic and dries the desiccants activating the attic ventilation fans and thereby removing moisture. The status of the fans is determined every five minutes. If the exterior humidity is lower than that inside, the ventilation fans are activated. Otherwise they remain unpowered. During the night the ventilation ends and the desiccant reabsorbs moisture from the space during NightCool operation….”

]]>