I have again set up the 1/3 HP aquarium chiller that I bought in 2016. This time outside so that the heat from the chiller is not released in the utility room. The controller is inside and the wiring and piping is routed through the outside air vent for the wood stove.
I did a similar test with well water running through the floor piping last year, and it seemed to cool the floor but I didn’t keep it up worried that the constant flow of well water might have an impact on our water supply. I was capturing the water used in a barrel outside and then using that to water the fruit trees.
Water Barrel
With the chiller itself outside I used the existing water in the radiant loops to feed through the chiller and back into the floor. I tapped into the system through the valve drains.
Drain valves opened
The drain valves feed a hose that allows me to let air in the piping escape when I start the heating system in the fall. I put a dual valve on the hose spigot and attached a long 1/2″ flexible stainless hose to that.
Dual valve and hose connection
The return pipe is attached to the cold water return for the furnace but the furnace is separated from the flow with a shut off valve. The chilled water flows through any zone that has an open drain using the system pump which is disconnected from the zone valves and plugged directly into the chiller controller.
Existing system pump
The electrical cord and hoses are threaded through the outside air intake for the wood boiler and that duct is disconnected for these pipes to use that access to the outside.
Outside air duct for piping and electrical cord
I didn’t break the drywall shown in this photo, this was an area the installers had difficulty reaching because of the water tank. Eventually I will have it fixed.
I cobbled together a bit of a shelter for the chiller outside. The chiller is black so I was trying to keep it sheltered from the sun.
Chiller Shelter
I had to cut the pipe for the duct to thread the wiring and the hoses through it. but a shorter pipe will work as well for the winter air duct.
Chiller piping in air duct
The big question is does it work?
It does cool the floor which helps keep the inside temperature below the outside hotter temperature. The controller reads between 69 and 73 degrees when I look at it. However the cooling is not enough to overcome the heat being radiated into the house from the trombe wall, appliances, and occupation of the spaces. The temp inside hovers around 80-82 when the outside temperature is above 89. But it does not seem to get hotter than that. With the ceiling fans inside it is tolerable.
At night the temperatures get lower and I open the windows and use a fan to blow cool air in the house, but even if the outside temperature is in the 50’s at night the house does not get below 76 degrees. It just holds heat really well.
I added a zone at a time and when I added the last zone it appeared that the floor throughout did not get as cool. So it seems that the best setting involves three of the four zone valves. The last zone is actually two separate piping loops and that is the one that seems to stretch the system a bit too far. Although it has not seemed to make a difference in the daytime indoor temperature to have a less cool floor overall. I don’t have a temperature reading for the floor, but it feels cool to the touch like a concrete floor might if it were in contact with the ground, which ours isn’t so it is not normally cool without the chilled water running through it.
I started the Energy Recovery Ventilation system again but found that the variable switch really wasn’t variable. Nor did it work to turn the system on and off. But it was running the ERV at about half speed or 3.24 volts that were not being modulated by the controller. I am guessing I have something wired incorrectly. So I ran the ventilation for a few days but now I’m hoping to fix the on/off so I disconnected it again. What a long process this has been.
And I still don’t have a very effective cooling system in the house but some cooling seems better than none.