In this Instructable I'll show you how I made a shade screen for my central AC condenser.
The condenser is in direct sun from 9 AM to 1:30 PM. I have no trees for shade so I decided to build a shade screen in order to lessen the load on the unit and hopefully reduce my electric bill.
Keep three things in mind when laying out your plan: air circulation, air circulation and air circulation.
First, I wanted to keep any vertical shade cloth at least two feet away from the unit because air circulation is very important.
Second, I didn't concern myself with shading the top of the unit. I figure the fan blades are shading the north side somewhat. I didn't want to restrict circulation by building anything that would cover the top.
Third, the shade cloth on the sides does not extend to the ground and is breathable.
I think I came up with a design that offers maximum shade without obstructing circulation.
Thanks for checking out my instructable. I look forward to your feedback.
Step 1: Materials & Tools
4 - 10' lengths of 3/4” PVC pipe ($1.39 ea)
4 - 3/4” T's ($.39 ea)
6 - 3/4” 3-way 90 degree elbows (<$16 on ebay)
PVC Cleaner (optional)
PVC Cement (optional)
3 - 4' rebar ($2.65 ea)
1 - auger style anchor 1/2” x 15” x 4” ($4.99)
6' - 80% Shade Cloth – 6' wide ($2.05/ft)
14 Fabric clips to hold shade cloth ($.99 ea)
Several feet of wire (or bungee cords) for hold-down
Levels, 2' & 4'
Painters tape or duct tape
Pencil or marker
Saw or PVC cutter
Large (water pump) pliers (shown in Step 19 Pic 2)
Step 2: Figure Out Where the Shadows Fall
I won't tell you how I did this because when I was done, I thought of a ridiculously simpler way of doing it.
You have to plot how the sun travels across the sky in relation to your AC unit. My AC is shaded by my house after 1:30 PM so my structure only needs 2 sides (an “L” shape) to protect it from the morning and mid-day rays. If your condenser is on the south side of your house and gets full sun from morning 'til night, you'll have to build a “U” shaped frame. If you're smart enough to find this website, I know you're smart enough to adapt the plans to your particular application.
The diagram shows the top view with the six posts marked A through F for easy reference.
Lay two sections of PVC pipe on the ground, at right angles to each other, two feet from the condenser. (Refer to the diagram. One pipe lays on the A - B line and the other along the B - C line.) The intersection will be the location of Post B.
Hammer a rebar 18” into the ground for Post B. Check for plumb every few strikes to keep the rebar fairly plumb.
If you hold the 2' level and the rebar with one hand, you'll find it's fairly easy to keep it plumb by moving the level around every few hits.
Step 3: Positioning Posts a & C
Go out early in the AM just before the sun hits anywhere on the condenser.
Hold a section of PVC pipe upright against the “B-C” PVC on the ground. When the sun hits the condenser, move the PVC in your hand along the PVC on the ground until the shadow of the upright pipe is a bit to the right of the condenser.
Hammer a rebar into the ground at that spot. This is the location of Post C.
Later in the day, you'll do the same thing along the “A-B” PVC on the ground, but you'll locate Post A a bit to the left of the shadow.
The A-B-C angle will be 90 degrees.
This step may take a few days. You'll be surprised at how quickly the earth rotates, causing you to miss your opportunity for that day. Note the time and arrive 15-30 minutes earlier the next day. This step took me 5 days.
Also, I built this at the end of June when the sun is highest in the sky. I'm not an astronomer, but I think that if you build it in September, you may want to move posts A and C 6-12” farther away from Post B. It can't hurt.
Place a 10' length of PVC pipe on each rebar to prepare for Step 4 tomorrow. They will lean a bit, but that's okay..
Step 4: Positioning Lower Horizontal Pipe (B to C)
On the next sunny day, go out in the early morning to mark the low shadow points on Posts B & C.
Use the 4' level horizontally and place it on the sides of B&C. Move it up or down until the shadow of the level hits below the bottom of the compressor.
Put a piece of painters tape on Post B at the top edge of the level. Center the bubble and put a piece of tape on Post C.
Double check that the pieces of tape are level with each other and the shadow of the level is below the base of the condenser.
This was about 8:20 AM when the sun rose above the roof of my neighbor's house.
Step 5: Positioning Lower Horizontal Pipe (A to B)
When the shadow of post B is at the left edge of the unit, mark the low shadow points of A & B with the tape and level as you did in Step 4.
This was about 9:30 AM.
Step 6: Cutting Posts B & C
Steps 6 to 16 deal with cutting and dry fitting. DO NOT use PVC cement at this time.
Take Post C off of the rebar and cut it 1” below the tape. (This allows for the height that the “T” will add.)
Slide a “T” on it and place it back on the rebar as shown.
Repeat with Post B, making sure you cut at the B-C tape.
(Disregard the A-B tape on this pipe. It is there to help with locating the shadow and it's useless now that you added the "T".)
“T”s on B & C should face each other.
Place the level on top of the B & C “T”s. If you did everything right, they should be level.
Step 7: Cut Lower B-C Horizontal Cross Piece
I didn't use the tape measure for any of the following cuts. I inserted one end into a fitting, judged the length against the opposite fitting, marked, cut & inserted.
Insert a pipe in the horizontal of the “T” on Post B.
While holding that pipe against the “T” on Post C you can judge how far into the fitting the pipe will go.
Judge the PVC post for plumb, mark the pipe with a sharpie and cut.
Check that posts are still plumb. If not, shorten the pipe or cut another a bit longer. This does not have to be perfect but you don't want it to look like Ray Charles built it.
Step 8: Cut Post C to Finished Height
Insert a piece of PVC into the “T” on Post C. It must be taller then the compressor.
Lay the 4' level on the compressor with the end touching Post C.
Make a mark on Post C on the top edge of the level and cut the PVC on that mark.
Step 9: Relocate Post B Rebar to Post E
Pull up the rebar at Post B.
Estimate locations for posts D and F. The C-D line will be perpendicular to the house. The A-F line will be parallel to the house.
Keep in mind that all intersections are 90 degrees.
Estimate the D-E and E-F lines and hammer the rebar in at Post E location.
PVC for Post B will now rest on the ground.
Of course, you can put rebar at each post but I'm too cheap. Also, if (when) the AC needs service, the whole frame can be lifted off. When re-installing, I'll only have to line up 3 wobbling posts instead of 6.
Step 10: Extend Post B, Cut Post A
Insert a short piece of PVC into Post B. It should extend higher than the tape on Post A.
Place the level at the tape on Post A, center the bubble and mark Post B with a sharpie at the same level.
Cut Post B 1” below the mark.
Cut Post A 1” below the tape.
(I mistakenly removed the tape from Post A so the instructions differ a bit from the photos. Sorry for any confusion.)
Step 11: Install a to B Cross Piece
Place “T”s on Posts A and B, facing each other as shown in the photo.
Measure, cut and install just as you did with the horizontal pipe between B & C.
Step 12: Extend Post B to Finished Height
Insert a piece of PVC into the “T” on Post B making sure it extends at least as high as Post C.
Place the level on top of Post C, center the bubble and make a mark under the level on Post B.
Cut Post B on the mark.
Step 13: Extend Post a to Finished Height
Insert a piece of PVC into the “T” on Post A making sure it extends at least as high as Post B.
Place the level on top of Post B, center the bubble and make a mark under the level on Post A.
Cut Post A on the mark.
Step 14: Cut PVC for Post E
I picked up a piece of PVC and placed it over Post E rebar and believe it or not, it was exactly the length (height?) I needed.
You however will probably have to put the level on Post A, make a mark on Post E and cut it to length.
At this point, your bubble should be centered when placing the level on any 2 posts (A to B, B to C, A to E, B to E and C to E).
Step 15: Cut PVC for Posts D and F
Stand a piece of PVC at the spot you want Post F.
I eyeballed a spot that would make a 90 degree angle between Posts A & E.
Holding your level on any other post, line it up with Post F. Make a mark under the under the level and cut the post.
Do the same for Post D.
Put the 3-way fittings on all of the posts, aiming the open ends toward the adjacent posts.
Step 16: Connect the Posts
I started by inserting PVC into the fitting on Post A aiming for Post F.
Holding Post F and the horizontal pipe, I marked where the pipe would seat all the way into the Post F fitting.
I again estimated where Post F would make a 90 degree angle between Posts A & E
Cut the pipe and insert into Post F.
Work your way around until all the posts are connected.
Step 17: Install the Anchor and Attach to Frame
Screw the anchor into the ground near Post E.
Attach wire to the anchor.
Extend the wire up to the A-F horizontal pipe and wrap it around the pipe near Post F.
Attach another piece of wire to the anchor
Extend the second wire to the upper B-C horizontal pipe and wrap it around the pipe.
Don't go crazy with the wire – someday you'll have to remove it to have the AC serviced.
Step 18: Install Shade Cloth
Turn off your air conditioner. You can't install the shade cloth if it's blowing all over the place.
Unfold and lay the shade cloth over the frame and condenser, Most of the excess cloth should hang over the A-B and B-C sides.
Make sure you have enough cloth (2-3") wrapped around the PVC so that the cloth is sandwiched between the clip and the PVC. In other words, the clip should not come in direct contact with the PVC.
1st clip went on the A-E pipe near Post E (avoiding the anchor wire).
2nd clip on C-D pipe near Post D
3rd clip on A-E pipe near Post A
4th clip on C-D pipe near Post C
Step 19: Install Shade Cloth (cont.)
Pull the shade cloth taut and install 3 clips on the lower B-C horizontal pipe.
Pull the shade cloth taut and install 3 clips on the lower A-B horizontal pipe.
Step 20: Tuck & Trim Excess Shade Cloth
There is excess shade cloth at post B. For now I just tucked it in to keep it from flapping in the wind.
On top of the condenser, the cloth must be trimmed.
Cut at a 45 degree angle from the edge of the cloth to the Post E fitting as shown in the photo.
Trim along D-E and E-F leaving enough cloth (about 2-3 inches) to wrap around the pipes.
Step 21: Install Final Clips
Pull the shade cloth around the pipes and install 2 clips on each.
If the cloth is a bit loose you can rotate clips around the pipes to tighten it up to a point. If its really loose, pop some clips and try again.
Turn the AC back on.
Step 22: P. S.
I have yet to disassemble the frame for gluing. The “T”s are so tight I had to use a hammer to get mismeasured pipe out of them. The 3-ways were not as tight but the shade cloth is holding everything together.
I only used 3 rebars because someday I'll have to remove this contraption for AC repair. I figured it would be easier to line up 3 wobbling PVC legs instead of 6 when reinstalling.
I'll probably take the cloth off in the fall. No sense leaving it out all winter and subjecting it to snow loads.
I plan on painting the clips and PVC black next spring. I think it would look better from the street. On the other hand, would a white tarp reflect heat?
This just in: My electric bill came and it's $.13 (yes, that's thirteen cents) lower than last month! What will I do with this windfall? Seriously, the average temperature was 2 degrees higher in August than July so I'm sure I saved a few dollars. In a few years I think it will pay for itself.
Thanks for checking out my instructable. I look forward to your feedback.