Sorry if you have been on the edge of your seat waiting to learn about what house stuff we’ve been up to lately. Today we summarize (some of) the trials and tribulations of installing our second heat pump system. A couple years ago, you may recall, we installed one for the upstairs to replace its “natural convection” heating.
The new system serves the first floor and the basement and replaces the ancient gas furnace that was removed during construction. While we were at it, we went ahead and replaced all the ductwork and the old register covers, just for fun — and because the old ones were rusty and full of dead camel crickets. The process took a few months.
Acquiring the unit itself is always something of a challenge. You can’t just order it on Amazon, apparently. An HVAC technician acquaintance of Amanda’s dad ordered it for us at a distributor. We got one that was slightly more efficient than the current standard in-stock models, so it took a few days to arrive. When it did, we were able to pick it up without the technician being present – but I don’t think we would have been allowed to order it by ourselves.
Amanda’s dad and I did our best to level the sloping ground in the area where the new unit would sit. I think the two units are technically too close to each other and the house, but what can you do when you are sandwiched between a gas meter, a house, a hill, and a super-close property line?
Once we got the outdoor unit (the compressor) and the indoor unit (the air handler) in place, it was time to figure out the duct work. Unlike the upstairs system, this one has two returns (where air is sucked into the system for heating or cooling), one in the basement and one in the kitchen. As a result, we needed a longer return than last time, when we made the return with plywood and flex duct. This time we chose to have a rigid metal return built for us, along with a short trunk line to carry the conditioned air to two large flex ducts. This is nice, except that you have to be really good at measuring, since you’re just giving measurements to the fabricator.
Setting the return and trunk line in place on top of the unit was a puzzle, and things were tight – a bit too tight, to be honest. We had to shift the trunk line over a bit to get it to go up through the floor where it needed to fit. Since we did things backwards (you should always put the biggest things in the walls first), there were electrical cables in the way, some of which had to be removed and rerouted.
In hindsight, we should have measured again before getting the pieces made, since we ended up having to get another duct piece made in order to shift the return line over to fit through the opening between levels. It all worked out though.
We cut the holes for the returns out of the big piece that we had ordered, and were able to use the extra metal from the larger return opening to create a cap on top of the return line. Pre-drywall, we covered the large hole in the kitchen with plywood to avoid having small children be mesmerized by the opening and either fall into it or drop various items into it.
Next time: flex duct, register boxes, and more!