Showing posts from 2019

Cross Ventilation Heat Recovery Concept

Since this blog is still getting traffic (from what I naively hope is relevant industry people, not bots), I thought I would share another ventilation concept that is similar to the StackHR concept in that it utilizes hollow core slabs and provides heat recovery and preheating of the ventilation air. All credit for the idea goes to my dad who came up with the concept when I pitched the original StackHR concept for him. I have sketched the concept below: If it isn’t completely clear what’s going on from the sketch here comes an explanation: Half of the hollow core concrete slab cavities are open to the windward side of building, other half are open to leeward side. Openings are provided between the cavities and the ventilated space opposite of  thefacade opening. Air enters building on windward side, passes through slab, enters ventilates space on leeward side, passes through ventilated space, exits ventilated space on windward side, passes through slab, exits building on le

Invention entered public domain

Today it is one year since I filed a provisional patent application for the StackHR concept. As I have chosen not to follow that up with a non-provisional patent, the idea has now entered the public domain as of today. I probably won't be able to find time to make a publishable article on the subject any time soon, and I think the same goes for professor Zhang, who has, however, told me that he will keep it ready in the drawer. It is my hope that somebody will come across this blog and pick up the idea, and develop it to the point where it can find real world applications. Now the idea is at least free for anyone to use however they might want.

Research paper

It's been a while since my last post, but that doesn't mean that nothing has happened. I defended my thesis in late April, and luckily the panel seemed veryv impressed with my work, and had only minor remarks and comments for corrections. I was, therefore, awarded a grade of 12 (highest possible grade in Denmark). I am currently working with my supervisor, professor Zhan, on a possible release of the work as a research article in a scientific journal. With the both of us being busy with other work right now, it might be a while before this actually becomes a reality though. I will make sure to keep you posted on here.

Final Thesis Report

Here is the finished report. The thesis defense is taking place on the 29th of March at Navitas in Aarhus, Denmark. If you are interested in attending the defense or would like a copy of the appendix just send me an email ( 

First results from experimental setup

With all of my classes and finals being over I'm now able to focus my attention on the StackHR project and writing my thesis. I have been making a lot of progress on the project lately, so I think it's high time for a little update here on my blog! For the thesis I'm focusing my attention on the heat recovery performance when operating at laminar and transitional flow conditions. The setup basically consists of the coaxial heat exchanger "ventilating" a "room" that is represented by two plenum boxes. The two boxes are connected with a duct, through which I'm moving air with a couple of small PID controlled desktop computer fans. The fan speed is varied so that a pressure differential between the two boxes, equal to what would naturally occur due to stack effect in a full size setup is maintain at all times. Below are a couple of pictures of the actual setup: I have already gathered a bunch of data, and I have been really s