Posts Tagged ‘hvac’

Last summer I ventured into the attic and tackled a project aimed at more efficiently cooling my condo. I installed air ducts to pull the hottest air down from the ceiling and into the air conditioner unit in the basement. I used vent covers that could be opened in the summer and closed in the winter. It worked pretty well.

Now I’m aiming to do the same thing for the winter. For about $25 in parts, I’m installing a return air vent in the basement to suck in the coldest air and heat it. I did most of the work today – cutting the drywall and assembling the duct piping – and need only to obtain a six inch circular hole saw to complete the project. Hopefully I can do that over the next week or two.

What I really don’t understand is why most homes aren’t built with more efficient return air ducts in the first place. Is it because builders know most home owners won’t open and close the vents twice a year with the changing of the seasons? It blows my mind…

A little over a week ago I posted a picture of some duct piping I creatively put together to attack a problem with hot air in the condo. That solution was obviously temporary – and given that I had today off from work and the weather was supposed to be mild (in the upper 60s), I took the opportunity to start putting the permanent solution in place. Up into the attic I went…

As you can see, it was pretty warm in the attic despite only being 67ish outside. The sun beating on the shingles for several hours this morning is the culprit.

I started with the vent into the A frame of the cathedral ceiling. Used a 14×6 opening for this one. I had to pull back a lot of insulation to get at the drywall.

This is a shot of the transition out of the wall cavity I’m using as a pipe. This is directly above the return air duct vent below the thermostat. You can see the top side of the can light in the hallway by my left foot. The transition piece is a 14 or 12 by 3.5 that’s made for this purpose. This was the hardest part of the whole day: I had to cut through 3 2x4s laid on top of each other to get into the cavity from the top… finally borrowing a reciprocating saw to make it easier.. otherwise I’d probably still be up there drilling holes. After about three hours, I’d gotten it trimmed and perfectly sized.

I used six inch piping throughout.. a y-pipe here allows me to put one vent in the A frame of the living room and another into the master bedroom (which gets really warm on summer afternoons as it’s on the west side of the condo).

I did quite a bit of eyeballing on this project… not typical for me but it worked out well. Here you can see the two pieces that will eventually connect.

By this point, I’m sweating like there is no tomorrow. It’s climbed to 70 outside and about 105 inside.. enough to max out the thermostat.

Here’s the cut and placement of the pipe for the master bedroom. Used a 12×6 here.

Here’s a shot from above the master bedroom showing the entire system. I had to break from the project to head to a 4th of July party so I left the duct taping and clamping for tomorrow. I also need to insulate the pipes to prevent the hot attic air from warming the air in the pipes on the way to the air handler.

After returning from the festivities earlier than expected, I finished the drywall and vent work on the visible side. Here is the A frame vent. Almost looks like it has always been there.

Here is the master bedroom vent. A little close to the door for my liking but there is a few inches of clearance between the edge of the vent and the wall. Both vents have levers for opening and closing so this should allow a lot of flexibility for efficient cooling.

Tomorrow I’ll finish up and in addition to a little work in the attic, I need to open up the bottom of the wall cavity and seal off the existing vent (below the thermostat) so that the suction is from the two new vents in the ceiling. After tomorrow, bring on the hot weather!

I’m not done with the garage project… I’m not even any further than I was last weekend. This past week and a half has been busy with wrapping up my summer MBA class and hosting colleagues from North Carolina, Texas, and Canada (in addition to work full time, etc.). But leave it to me to get frustrated with something and tackle it head on. I did that tonight with the HVAC system in our condo.

The problem is that the air conditioner runs for hours and hours. It has ever since we moved here over two years ago. The sun beats on the back of the condo all afternoon and the back inside walls are warm to the touch (having dark brown exterior walls that absorb all that heat doesn’t help). In conjunction with this, the return air ducts are on the floor of the main floor. Anyone with any amount of science background knows that heat rises so having the return ducts on the floor doesn’t do us any favors in the summer when trying to get rid of the heat. I actually measured the difference last night before bed and a thermostat at the floor close to the return duct measured a full 10 degrees cooler than the wall thermostat four feat up the wall. That explains why my feet are cold and the rest of me is warm when on the main floor. Its hard to sleep at 80 degrees and seeing that the floor was that much cooler pushed me over the edge.

I went to Lowes and picked up some ducting supplies. This is what I built: pretty cool if you ask me. You can see the two return ducts on the floor in the lower left and lower right.. and the thermostat on the wall. Within a matter of 10 minutes of setting this up, the wall thermostat dropped two degrees (it had taken 4 hours to drop it one degree prior to this).

Eventually I plan to run a return line up into the attic to connect to the peak of our vaulted ceiling and also another one to the ceiling in the bedroom. I’m also going to put one in downstairs near the floor to help keep the basement warm in the winter (another issue).. I’ll delete one of the existing main floor vents and use levers built into the vents to control settings for winter and summer. Man, I love efficiency!