Heat Pump!

First I got hot water, and now I have heat!  Life is good.

I finally finished attic prep, found a good heating contractor, and shortly thereafter Nate, Ryan, and Jeff spent two days at my house installing a new heat pump, air handler, and primary ducting.  They did a fantastic job!  Comfort at the touch of a button.

So what is a heat pump?  Oddly, perhaps, I thought everyone knew, but when I told people I was getting a heat pump, I was met with blank faces and the inevitable question — "What's a heat pump?"

The short, non-technical answer is that a heat pump is like central air conditioning in the summer (pumping heat from inside the house to the great outdoors), but in the winter a valve is switched in the same equipment to pump heat from outdoors to the inside of the house.  But wait, you say there's no heat outside in the winter?  Actually, in milder climates, especially, there's lots of heat outside (it just doesn't feel very warm to humans).

Take my word for it (or google it).

So why a heat pump, instead of another gas furnace?  Didn't like burning gas (fossil fuel & fire threat), and I have the ambition to get solar panels (and battery storage) in a few years.  Free electricity for life (and free fuel if you have an electric car).

The new outside unit looks like this (very much larger than the very old, inefficient A/C unit it replaced):

It is connected to the air handler in my laundry/utility room via two refrigerant lines and an electrical control cable.  The photo below shows the air handler opened up during installation.  The vee-shaped tubing matrix is the heat exchanger; the warm fluids in the tubes heat the air passing through it.  The black cylindrical thing below that is the blower which takes air from inside the room and runs it up from bottom to top, going through the ceiling into the attic ducting.  Below the blower is where the electrostatic air cleaner goes.

This is what it looks like all buttoned up:

The white tubing is the condensate drain line, useful when moist house air hits the cold heat-exchanger fins (mostly in the summer).  Water condenses and runs down into the floor drain (dehumidifying).  Out in the hallway on the right of the photo, up on the wall, is the new programmable, touch-screen thermostat.  It does way more things than I have a need for.

It's set for 69˚, but the inside temperature there is 74˚.  Photo was taken in the afternoon on a warm, sunny day (actually high of 74˚ on December 14).  The temperature inside the house slowly rises during the day (when it's sunny), and then slowly drops during the night.  It used to rise and fall much faster than it does now, but I now have much more insulation in the attic (and double-glazed high-efficiency windows, and some thicker walls, as some of you loyal readers may recall).

So the heat pump actually does not run that much, pretty much not at all after 7 a.m. until sometime in the early morning hours.  But I have programmed the variable-speed air handler to come on at low speed for some portion of every hour to give the Trane "CleanEffects" air cleaner something to do (the outside air in this arid climate is dusty).  This also means that the air inside the house is thoroughly mixed together, pretty much a constant temperature everywhere—cooler at night.  Very nice indeed.

The unseen pieces in the attic are largely responsible for this.  So up to the attic!

The air exits the top of the air handler into something called a plenum — basically a big sheet-metal box.  Out of the backside of the plenum there are three flexible ducts which travel the short distance to the rooms adjacent to the laundry room.  In this photo the plenum is at lower right.

Leaving the front of the plenum is the rigid 14-inch diameter sheet-metal main duct, which travels down toward the other end of the house.  Unlike flexible ducting, which is shaped by a spiral of wire (giving the interior a corrugated appearance), the interior of the rigid metal ducting is smooth, and therefore offers much less resistance to the flow of air.

That makes the ducting system more free-flowing and energy-efficient.  The short flexible branch ducts that interconnect with the main duct go to the other five registers in the house.

Heat loss is greatest where the temperature gradient is the steepest — hot and cold separated by a very short distance.  That condition exists, for example, where hot air in a duct is right next to cold air in the attic (winter), or the opposite during the summer, when the attic temperature can reach 130˚ and air inside the duct can be close to 60˚.  If those extremes are separated by less than in inch of insulation (my old system), you will be cooling the attic in the summer and heating it in the winter.  Enter insulation — lots of it!

At least 10" all over the attic, and that much over all of the ducting (and over all the water supply lines as well).

It's like an ocean of insulation :-)  You can't see it from below, but you can feel it working.  Money spent on insulation is money in the bank.

Looking forward to experiencing the air conditioning next summer . . .

So, catching up on some other things I've been getting done . . . like the door trim and baseboards installed in the master bedroom (setting off the new bamboo floor).  The gap around the floating floor was wider in places than my usual baseboard, so I had to first install a 1x3 board (3/4" thick), and add regular molding on top of that, for a taller than usual baseboard for a modern house (it's growing on me).

And while I still haven't found a good supplier for my main kitchen countertop, I did silicone in my undermount stainless steel sink, and install the drain for that.  Why worry about the drain, when I won't be able to install the faucet until I get the countertop done?  Dishwasher.  It's been installed for some time, except for its drain line, which connects into the sink's drain line.  So I haven't been able to use it, until now.

I used an air admittance valve again for this installation (the white device sitting atop the black ABS pipe assembly).

And here is the drain system completed (going to the dishwasher to the left of the partition is the electrical connection on the top, then the drain line, then the hot water supply line):

Haven't used the dishwasher yet; I've been hand-washing so long that I haven't yet been able to start a new habit (although Friday night pizza-making produces lots of dirty paraphernalia, so maybe soon).

Next?  A rare rain event tomorrow night, and then a long string of sun, so I'm planning to take down the rest of the chimney and rebuild/stucco the wall behind.