A new distributor of building products from Europe has set up shop in Brooklyn, New York. The company, called Four Seven Five, was recently founded by a trio of Passivhaus consultants: Floris Keverling Buisman, Sam McAfee, and Ken Levenson. Four Seven Five plans to import air-sealing products and ventilation fans from Germany, as well as HVAC equipment from Denmark.
One way to describe Four Seven Five: it’s the Small Planet Workshop of the East coast. Like Albert Rooks of Olympia, Washington, the Brooklyn triumvirate behind Four Seven Five imports European air-sealing tapes. Rooks sells Siga tapes, while Four Seven Five sells tapes manufactured by a competitor, Pro Clima of Schwetzingen, Germany.
All kinds of tapes
Pro Clima makes window tapes, sheathing tapes, housewrap tapes, and vapor-retarder membrane tapes. Like tapes made by Siga, Pro Clima tapes have an aggressive adhesive that is free of VOCs.
Like other high-quality tapes, Pro Clima tapes come with a slick paper peel-away backing. We’re all familiar with the frustrations of such tapes: for one thing, few carpenters have fingernails that are sharp enough to get the corner of the peel-away paper started. And when the paper backing is finally off, the tape tends to curl into itself, causing the dreaded “sticky side to sticky side” disaster. Okay — that length of 80¢-a-foot tape is ruined. I guess it’s time to cut another length of tape and try again to peel away the corner of the paper backing. I wish I had a teenager with sharp fingernails to help get this corner started …
Of course, once you have successfully navigated the peel-and-stick-and-stick dance, the tape works great.
Most Pro Clima tapes come in a single width (3 3/8 inch). Each roll of tape is between 65 feet and 98 feet long and sells for $33 to $87 per roll.
Other Pro Clima products
In addition to tapes, Pro Clima also manufactures caulks, housewrap, and “smart” vapor-retarders. All of these Pro Clima products are available from Four Seven Five.
Pro Clima’s smart retarder is called Intello Plus. This product is installed on the interior side of a wall or ceiling, directly under the drywall. Intello Plus has a permeance that varies from 0.17 perm during the winter to 13.2 perms during the summer. Because of its variable permeance, Intello Plus (unlike polyethylene) can be safely used in an air-conditioned house.
For some odd reason, Intello Plus comes 59 inches wide, so you’ll need two rolls to stretch from the floor to the ceiling. (Of course, Pro Clima suggests that you tape the resulting horizontal seam with one of their tapes.) Each roll of Intello Plus measures 807 square feet; the cost is $324 per roll.
Pro Clima offers two types of housewrap: Solitex Mento 1000 ($203 for 807 square feet) and a heavier version, Solitex Mento 3000 ($235 for 807 square feet). If the Solitex Mento seams are carefully taped, either product can double as an air barrier.
Four Seven Five also sells rectangular patches (most of which are about 5 inches square) to seal around wiring and pipe penetrations in air-barrier membranes. Called Kaflex patches, they are made of a flexible airtight fabric. Several versions of these Kaflex patches are available; prices range from $5 to $8 each.
A “magic box” from Nilan
Many Passivhaus builders in Europe install an integrated HVAC appliance that provides ventilation, space heating, and domestic hot water — a type of appliance has been nicknamed a “magic box.” (For more information on these appliances, see A ‘Magic Box’ For Your Passivhaus.)
Four Seven Five is the first U.S. importer to distribute a European “magic box” — namely, the Compact P, a magic box manufactured by Nilan of Hedensted, Denmark. The Compact P is an air-source heat pump with a very modest space-heating capacity of 7,165 BTU/h — suitable for a Passivhaus, perhaps, but insufficient for most cold-climate homes. At an outdoor temperature of 16°F, the unit can provide 3,273 BTU/h (about 959 watts) to heat domestic hot water. If necessary, a 1.5 kW electric resistance heater kicks in to supplement the output of the air-source heat pump.
The Compact P includes a heat-recovery ventilator rated at 188 cfm. Four Seven Five will sell the Nilan Compact P for about $13,000.
An intriguing new approach to heat-recovery ventilation
Lots of people like the performance of heat-recovery ventilators (HRVs), but not many people like the high cost of purchasing and installing the equipment. It’s complicated to run ventilation supply and exhaust ducts to seven or eight rooms, so the typical installed cost of an HRV is $2,000 to $3,000.
Is there a simpler way to provide ventilation that includes heat recovery? Perhaps. Four Seven Five will soon being distributing a small ventilation fan, the Lunos e2, manufactured by Lunos Lueftungstechnik of Berlin, Germany. The cylindrical Lunos e2 has a diameter of about 6 inches. It is designed to be installed inside a wall, but the wall must be fairly thick, with a minimum thickness of 11 7/8 inches. Lunos e2 fans are fairly unobtrusive; the indoor cover plate measures 7 inches by 7 inches.
Inside each Lunos e2 unit is a small 12-volt fan (powered by a transformer) and a perforated ceramic heat-storage disk. As air flows through the disk, the disk absorbs or gives up its heat.
Here’s the ingenious part of the Lunos e2 design: the fans are reversible. A Lunos fan is programmed to operate as a supply fan for 70 seconds, and then reverse itself and operate as an exhaust fan for 70 seconds. Fifty-one times per hour, the air flow reverses.
During the winter, the exhaust air stream heats up the ceramic disk. When the air flow reverses, the ceramic disk gives up its stored heat to the supply air stream. One minute later, the air flow reverses again, and the exhaust air streams heats the ceramic disk back up. The net result: The Lunos e2 is able to recover heat that would otherwise escape with the exhaust air stream.
The Lunos e2 fans are designed to be installed in pairs. A controller synchronizes the functions of the two fans: when one fan is operating as an exhaust fan, the other fan, which can be located some distance away, is operating as a supply fan.
Lunos e2 fans are very energy efficient. They draw only 2.8 watts at high speed (17.6 cfm). That’s an efficiency of 6.3 cfm/watt, about the same as a Panasonic FV-08VKS1 fan, which supplies 80 cfm at 11.3 watts (7 cfm/watt).
The Lunos e2 fan is rated at only 17.6 cfm. That’s not much.
How many Lunos e2 fans do you need for a small house? Let’s take an example: a 1,200-square-foot house with three occupants requires 35 cfm of continuous mechanical ventilation, according to the ASHRAE 62.2 formula of 7.5 cfm per occupant plus 1 cfm for every 100 square feet of occupiable floor area. So two pairs of 17.6-cfm Lunos fans would be adequate for such a house. (At any one time, two of the four fans would be operating as supply fans, and two as exhaust fans.)
The main disadvantage to the Lunos e2 fan is its high price. Four Seven Five plans to sell the fans for $1,200 a pair, or two pairs (the minimum number of fans necessary to ventilate a small house) for $2,250. That’s steep. So, to return to the question we started with — “is there a simpler way to provide ventilation that includes heat recovery?” — the answer is yes. Unfortunately, the simpler way is just as expensive as installing an HRV.