HVAC for our Brownstone

How to cool a brownstone and still be green? Geo-thermal would be great, but not a reality in an urban area (or our wallet). As Mayor Bloomberg recently commented, he didn't grow up with AC (either did I) so why is everyone complaining?? Good point, but between the heat and the humidity, it makes for mighty uncomfortable living.

We've spoken to a fair number of HVAC folks, and were disappointed that most just want to go with the standard central ducted systems with a couple of monster outside compressors. These systems have been the backbone of the AC market. Unfortunately, it means that you:

• are pushing air through ducts (inefficient and potentially unhealthy)
  
• have to open up ceilings for the ductwork (expensive and wasteful)
  
• power up a huge unit running to blow cold air into rooms that may not need it (not exactly Green!)
  

and before the HVAC folks say "just add zones!", yes I know, but how many zones are practical??

Don't get me wrong, when I was renovating a house in Louisiana, the central AC was the first thing I made sure was working. Wow, it's hot down there... But there are better ways: Mini-Split Air Conditioning - Read More...



Mini-Splits consist of a compressor/condenser (outside) and an air handler (inside). Connecting the two components are electrical cable, refrigerant line and a drain hose for the water removed from the house. They are connected via a 3" cable raceway, and the air handler is hung on the wall or recessed in ceiling. Simple, clean and pretty darn green.



The outdoor condensers can support up to 4 air handlers, each of which have their own controls for temperature, dehumidifying, fan. Some even allow you to add a short amount of duct, so you could cool a bathroom without having to put in another unit.


Our brownstone will likely be configured as follows:
Garden Apt: one outdoor condensers, two air handlers

• one in bedroom, one in living room

Main House: 2 outdoor condensers with 5 total air handlers

• one on parlor floor, one in Master BR (with short duct to Master Bathroom), 2 on top floor for each bedroom.

Every room will have it's own thermostat/remote that will allow us to cool the rooms that need it, and maybe just de-humidify the rest. They have an Auto Mode, which chooses how to best function based on temperature and humidity.

The units we'll be using are Fujitsu Halcyons. These are 21 SEER super high-efficiency units (the old Carrier ducted systems are typically 13 SEER).

We use these on another house that is powered by Solar PV, and not only is the AC unit nearly silent, at full blast it barely makes a dent in the power being generated from the solar panels. Also, we are getting ones with Heat Pumps, so that during the day, when the Solar PV is generating electricity, we could use them to heat the house and not have to run the furnace. Now THAT'S cool.

We're waiting on a few quotes, but when you take into account the labor being saved (no running ductwork everywhere) and the reduction in power, we're expecting them to be less than 1/2 the cost of a traditional ducted central AC.



[where: 10032]