|06-18-16, 04:39 PM
Join Date: Jul 2012
Location: Jacksonville, fl
Thanked 14 Times in 10 Posts
DIY Active HRV (Image Intensive)
Started up another spur of the moment project, and got quite a bit of progress done before the rain showed up (The then better half talked me into a house without a garage...). To make a long story short, we get TTW a/cs on warranty exchange fairly regularly. TTWs are basically glorified window a/cs designed for Through The Wall install with rear vents instead of side vents. I have had 2 12k btu units that were both out for condenser leaks hanging around for a while, and I had previously experimented with hacking up the blower housing to convert them into ducted units (mostly for my HPWH). It occurred to me, mount 2 evap sections on one base pan, and duct it into a Active heat recovery unit! I have been doing decent keeping the temps under control in the house with a 9k portable, but not in the traditional sense. The unit is completely outside with the cold air ducted in, so it is 100% fresh air, with a window cracked open at the other end of the house. We have a lot of reptiles, there is no smell any longer. So why waste that cold air out the other side when I could pass it through the condenser?
Interesting bottom coil. Its intention is to make full use of the condensate in the pan for free sub cooling.
Got both evap and blower assyms on the pan... and it just aint gonna fit.
So I cut the arse end off both pans and brazed them together. The pan is not completed as I was more curious to see if this whole idea was going to work first.
About 30-45min later had both sides bolted back down, everything piped up, and reused the original captube. Compressor even bolted down into its original location. And, the evaporator motors are still serviceable, unlike the first attempt.
Lost track of charge, but it was significantly less than the original 20.8oz, as I had to remove quite a bit. The SH was so high because it was frickn raining and I was too stubborn to quit...
Dont mind the kWh reading, its cumulative, and I havnt reset it in several months of using it as a test cord at work.
It was certainly doing a good job of pulling condensate, judging by the stream in less than 15min of run time.
So, all in all, not bad for a 3hr project. Next up, need to modify the blower housings to allow ducting, and build a case around it. Both motors are 3 speed, which will aid in balancing flow, and are only 25-30watts each on high. Unit is actually impressively quiet without that awful 3 blade condenser fan howling out the back. Curious to see how well it will maintain temperatures (at least during off peak times).
|active hrv, diy, hrv, ventilator