Inspired heat pump
Hi AC_Hacker, I have been reading your awesome thread while doing the research for building my own heat-pump.
Here is a bit of history on why I choose to build my heat pump. For the last 2 years I have been in the process of remolding my 1958 - 2800 sq ft house. In the process of doing so, I decided to rip out all the hydronic baseboards which was 1 zone for all rooms of the house and put in sub-floor heating (pex). I went from 2 zones ( second zone is basement slab) in the entire house to 7 zones on a 10 port manifold. Because sub-floor heating takes a while to increase the heat of the room, I installed a turbonics MVB 8-DHC for those days and nights when you want it to be warmer then what you have actually set the room temp at. I run the entire system off a raspberry pi with D18B20+ sensors in each room and instead of thermostats ive written a webapp which is accessible on any device. This all runs on an ancient 180k BTU American Standard boiler. This all works fine for heating except for the fact that the boiler is horribly inefficient (thinking about replacing with Takagi T-H3-DV-N - another story for another day...)
Now for the reason for the heat pump. because I live in a high desert the winters are brutal and the summers are hot. Yesterday it was over 100 degrees F. On days like this, the house gets to 85 and 90 degrees F, sometimes hotter depending on the previous days heat and if the night was cool enough to bleed off some of the thermal heat. the basement stays in the 70's but its 8" of cement with 2" of foam on either side (light forms built in 2003... old house moved to new basement) the top floor is 5" of spray foam but it still gets hot. So... I built the heat pump to chill water to run through the turboics MVB units, I also want to save the heat in a hot water tank or boiler mate because I run a tank-less water heater and my ground temp is 50 degrees F. If the tank gets saturated with heat, it will dump to a sprinkler line, for now... figure out something better later.
The pump is (free) 2 ton compressor and the heat exchangers are 5"x12"x3" (30 plates 120kbtu). the rest of the parts (valves and tubes) are also free from the recycling of hotel air conditions (they are 12kbtu 265-270v and even though I've tested them on my 220-240v. I read that its not good to do so.) Although I have done a lot of research, I found it to be a bit difficult to properly charge this thing based on what I've read about superheat and subcool. (could be because I'm am fairly new to the awesome world of refrigeration and heat-pumps or my exchangers might be oversize for this pump.).
Right now everything seems to be working as it should but I only have a couple days of operation. I was hoping to use some of the reversing valves I've acquired for making this a more versatile machine but haven't quite figured out how I'm going to do it yet.
Anyways, just thought I would stop in and share my heat-pump, which was mostly inspired by what you have accomplished.
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