The Kohilo Whole House Fan is designed to be more financially available (yes, that is a genteel word for cheaper) than our flagship units. How did we do this ? We replaced the motorized damper unit and electronics board with a backdraft damper.
A backdraft damper is pushed open with airflow and falls back (by gravity) when the fan is off. This provides a basic seal (nothing like our motorized dampers), but has no insulation. In severe climates the Kohilo grille will have to be manually insulated at the end of the season. We do provide an upgrade path for customers so that they can upgrade to the full AirScape functionality and convenience.
First of all, Thanks to everyone who responded to our survey of last year’s AirScape whole house fan customers. We had an amazing 20% response rate, which indicates that you
either love us or hate us – we’ll pick the former 🙂
There were a lot of glowing comments, but a survey is not an exercise in self congratulations. We take very seriously the few people who were unhappy with their purchases. What we want is to bring to zero, the number of people with unmet expectations. Our job is to make sure that you get a quality product, but also make sure that you understand the power and the limitations of our particular technology.
Now, for the mandatory post image. Here is the latest map of our sales. Every zip or postal code that had an AirScape whole house fan purchase gets a marker. Look at that – the Canadians are buying. So are the Floridians.
It was the best of times, it was the worst of times. (Don’t worry; that’s the end of the literary pillaging.) I poked my head outside this afternoon at 5 PM, thinking that maybe I should open the windows to warm the place up a little. As I go outside, I noticed that the neighbor’s AC unit was running. The inside temperature in my home was 72º, outside was 88º. So why am trying to warm up and the neighbor cool down?
Several reasons as it turns out. I’m living in an ICF (insulated concrete form) house that has one of our whole house fans installed. Whereas the neighbor’s house is a low mass stick framed house, and certainly has no whole house fan.
Of course whole house fans are great – but what seems to be a great combination is lots of mass to store “coolth” (made up word meaning the opposite of heat). I’ve been able to survive quite well all summer with just a whole house fan for cooling – no AC. That said,during the second week of 105º days, AC would have been nice for about 4 hours per day.
The goal of this project was to apply the energy saving concept of a residential whole house fan to an institution. Our local museum Science Works was a great candidate for this “experiment”. Everybody wants to reduce energy use these days and who better to show off some of the newest (and oldest) concepts than a science museum?
The Science Works building is a very robust concrete structure. That fact alone got us excited about putting whole house fans into the museum because we know that concrete has a large capacity for storing “cool”. We also know that summers in Ashland are plenty hot with a large diurnal temperature variation (big words for “it gets cold at night” ). And of course, what better way to cool the museum than with a couple of our whole house fans.
Since the fans would only run at night, and nobody spends the night here, we modified our 4.5WHF units to push a little more air. Basically we removed the noise attenuating ductwork. The plan was to use a pair of the fans, which will exhaust 10,000 CFM (cubic feet per minute) from the building. By using our 4.5WHF units , we made it easy for the contractor to provide well insulated (R-10) and sealed damper doors. A typical commercial project would involve ordering custom dampers and fans and probably many decision makers.
A clerestory window over a warehouse area of the museum was selected as the logical location because of its height (remove all that hotter air) and relative ease in waterproofing (no roofing work!). A scaffold was built and a local contractor (all organized by Science Works director Mark Dirienzo) installed the units.
So, we solved the problem of getting the air out, but what about letting fresh air in. It’s not practical to leave windows open all night, but whoever designed the museum must have been thinking ahead.Â We found 2 sets of dampers high up above the entry way.
Better yet, motorized actuators were found to be in working order. The plan is to setup an automatic timer that opens up the dampers and turns on the fans every night at 10:00 PM. The weather is predictable enough here that we don’t need anything more complicated.
Last night, we opened up the intake dampers and turned on the fans. No hard numbers yet, but we got the main entryway down to 67°, which is way better than the usual 78°. We’ll report back on the results as we gather data on temperatures and energy use.
10,000 CFM with outside air 10° cooler than inside
This yields about 9 tons of cooling.
We expect to be able to run the fans for 10 hours per night based on historical weather data.
We estimate a savings of 20% of the museum’s cooling energy.
We wanted to find out where our fans from 2008 ended up. This map has a dot for every zip code in which we have shipped at least one whole house fan. As we expected, California is the leader, for a couple of reasons: great opportunity for night time cooling, and great, big electrical bills (thanks Enron).
What surprised us is the amount of activity in other states. In fact, the distribution of our whole house fans looks very similar to the US population distribution.
We think a couple of factors are at work. People are rediscovering whole house fans as electrical prices rise (electricity seems to be recession proof BTW). Another factor (according to our surveys) is that people are looking for fresh outside air as an alternative to air conditioning.