Mini split keeps it warm

The house is consistently warm and comfortable even on the coldest days. Unlike the house next door, no drafty doors or chilly windows remind you the North Wind is blowing. It can be quite a shock to step outside the airlock.

Marc Bailey of BarlisWedlick recently asked us how the mini split is working. New models coming onto the market can handle colder weather than our model can, which has a lowest operating temperature (heating) of -5 degrees F. Our reply: The mini split seems to function fine at low temps. We have one 9,000 BTU (cooling) / 12,000 BTU (heating) ductless wall-mounted unit, Fujitsu model no. ASU9RLS2.


  • Most of the time the controls are set to “heat” rather than automatic, with the fan on. This seems to make the house warmer. It’s set for 70 degrees F.
  • Chris cleans the filter screens often. Performance is noticeably better when we keep the screens clean.
  • The ceiling fans help to distribute the warm air and even out the temperature throughout the house. If the ceiling fans are off, the first floor can be about 3 degrees cooler than the second floor.
  • The upstairs bedrooms are often about 2 degrees cooler than the rest of the first and second floor in the morning, which is probably because we keep the doors closed at night. In this very cold weather, the rooms may be 3 or 4 degrees cooler.
  • It is warmest on the open deck area above the kitchen, which overlooks the big South window and is closest to the mini-split. That’s my office area now. On cold days Chris has been using a portable Delonghi electric heater in his lower level studio, which is far from the mini split.

Our plans call for three mini splits in this three-floor house but we have only installed one so far. The walls are plumbed and wired for the remaining two, the installation of which will cost $3,000 each. We are waiting to see how the house feels to live in, and the lower level remains unfinished at this time. So far, we are finding that the mini split in the lower level is mostly needed for heating, and the one in the master bedroom is mostly needed for cooling.

For another blog entry, I’ll find out why some people call this sleek white box a “mini split” while others say “heat pump” or “air handler”.

Monitoring our energy use

Brian (L) and Jeremy (R) from CDH energy, along with Kapil Varshney (C) from The Levy Partnership install sensors to study our household energy use for the next year. Just humming along, the house was using the equivalent of three 100-watt lightbulbs, CDH said. Data recording unit will gather many points of energy consumption, as well as interior and exterior temperatures.Once a day, the data will be uploaded to a monitoring program via the internet.Temperature monitor for the Fujitsu mini-split heat pump. In our first winter, this provided the only extra heat we needed after the sun and the HRV had warmed the air.Several wireless temperature monitors are placed throughout the house.

Commissioning the HRV

Aubrey Geweber from Zehnder inspects our HRV for official commissioning, which means that he’s going to spend several hours examining the whole set up and adjusting the volume flow rates for normal operation in the house and the balance for outdoor air and exhaust air. A drywall screw rattling around in the exhaust fan may have been the source of occasional error messages on our control panel.Using a velometer to measure airflow from the vents and balance the system between rooms.The nozzle on the left is for the RETURN vent. On the right is an air SUPPLY vent. The openings on both are adjustable to control air flow. These are mixed in with our can lights on the ceilings of every room. The air flow is very quiet.

Aubrey estimates that about a half dozen houses in New York’s Hudson Valley have Zehnder HRVs, and there’s a lot going on in Brooklyn right now.

Barn sale

Many of our household items packed away in a storage container during the build were not needed and not missed. We set up a table at the barn sale in North Chatham to lighten up, and make a few dollars.

Touring a Blu Homes Breezehouse

Several years ago, when this company was still very young, we considered building a Blu home. We liked the precision and control of a factory-built product, and this brand sounded smart and high-quality. The illustrations on the website inspired modern-design-envy but not sufficient confidence (by now they showcase many completed homes). In our experience as first-time home builders, we can say that a house tour makes all the difference.

So, barely a month living in our brilliant new Passive House, we headed East out of Hudson on Route 23, to see the first Blu Homes Breezehouse in New York State. It was absolutely fabulous. Every room felt light and right, every green decision made sense, and every question we had was answered by a knowledgeable sales rep. It felt good to know that a steel frame supported those well-insulated walls and SIPs roof. It looked as chic as the crowd that came to visit this 2,320 sq ft home with 22 acres and a beautiful hilltop view, priced at $1.6 million.

Passive townhouses by Habitat

The crowd gathered in Hudson this sunny Saturday morning included some familiar faces. “That man looks like the nicest and most happiest to be here,” said our 8-year-old, nodding towards Dennis Wedlick. Dennis volunteered the services of BarlisWedlick Architects to design the Columbia Passive Townhouses for Columbia County Habitat for Humanity. The event was to dedicate the townhouses, which were built by Habitat volunteers alongside the future owners: families from Bangladesh and Haiti who each invested 300 hours in construction. We met Dennis, Alan, Liza, Mark and Jason of BarlisWedlick at this event just a block or two from their Hudson Studio. If Habitat aims to create community as well as housing, this was our connection.

Elements of the townhouses made us feel right at home – the same Intus windows and doors, thick walls, how the kitchen opens onto the living and dining areas, the HRV and heat pump. The dove grey walls and white trim are so lovely that said 8-year-old was reconsidering her choice of turquoise at home.

We’ve volunteered to help Habitat create a users’ manual for the HRV which, if anything like ours, lacks decent directions. Fortunately, it’s easy to use: Press speed 2 and leave it alone mostly; Press the Clock symbol for a 10-minute boost to speed 3 when the bathroom or kitchen needs extra ventilation. Set the heat pump on automatic. Clean all filters once a month or more in pollen season.