The Earth is what we all have in common.–Wendell Berry
A fact of modern building construction is that most cooling is produced by rooftop units. Improving the energy efficiency of rooftop units and connecting the sizing and operation of them to actual demands in the space would produce significant energy savings. Instead, most rooftop units are (over) sized by rule of thumb, using a tons... Continue Reading →
I came across an article recently about Climeworks, a Swiss company who is manufacturing machines to extract CO2 from the air. The machines look somewhat like a jet engine (see below) and they saturate a filter with the CO2, then extract it from the filter by heating it. One jet engine looking module extracts 150... Continue Reading →
Recently, I investigated the use of a variable refrigerant flow system with ground loop condensing for a school HVAC renovation. For the building in question, the ground loop was estimated to cost $405,000, and the savings produced would be expected to show an 8-10 year payback in order to be considered. I used Mitsubishi equipment as... Continue Reading →
A few years ago, I helped a hundred year old local high school modernize. Elder High School is a well known Catholic west side boys school with a strong alumni base. The original building was built in 1922 and there were major additions in 1959 and 1963. The school enjoyed a lot of support from... Continue Reading →
It’s the holidays and the end of the year. We have a new president, and I will be very surprised if the result of this is a positive change in energy policy and climate change plans. I attended a seminar a couple of weeks ago and the speaker related the story which got him involved... Continue Reading →
Writing about ground source heat pumps yesterday reminded me that people often refer to them as geothermal, which is a misnomer. Groundsource refers to installing a pipe in the ground and circulating water through it, and transferring the heat of the ground indirectly to heat or cool. Geothermal is a much rarer source of energy,... Continue Reading →
If you do a google search with those search terms, you won't get any exact hits. The hits you get will be regarding residential systems, which are much simpler. For residential applications, only the efficiency of the equipment itself (condensing unit and matching indoor A coil) is considered, not system efficiency or the combined efficiency... Continue Reading →
The recent cold temperatures reminded me of a situation that I encountered a few winters ago. This is a VRV condensing unit in its first year of winter service. Can you guess what the problem is here? It isn't a malfunctioning de-icing cycle. The outside temps were around freezing when this happened, and it didn't... Continue Reading →
