Results 1 to 13 of 13
Thread: Using AC during Remodel
-
07-14-2005, 03:23 PM #1
Regular Guest
- Join Date
- Jun 2004
- Posts
- 69
Hi, I am remodeling my house - living in one side while demolishing the other. I have visquined off half the house to keep the massive amounts of dust from the nice side I am living in. Now that its 100 degrees I am using the AC. My question is - is it ok to use the AC with it only able to draw intake air from half the house. I have left all the ceiling vents open on both sides of the house to keep the coil from freezing? When the AC is running the visquine seperating the two side of the house is pulled tight towards the return air like a sail

The house is 2650 sq ft with a 5 ton system.
Any suggestions or thoughts appreciated - its a new system and I dont want to ruin it.
Thanks!!
-
07-14-2005, 03:45 PM #2
Professional Member*
- Join Date
- Nov 2004
- Location
- SW FL
- Posts
- 5,271
Damper Adjustment
You seem to be on the right track.Originally posted by kuma
When the AC is running the visquine seperating the two side of the house is pulled tight towards the return air like a sail
Any suggestions appreciated -
I think that closing the diffusers 60% to 80%
on the " Renovation Side" of the house would be appropriate. RESULT: > ~70% of the air flow may be directed to the current Living Space.
I don't believe the total air flow would drop appreciably (> 20%).
How would a ~30% air flow reduction freeze the coil if the return air is ~75'F ?
Obviously, block return filter, if any, on the "Renovation " side. Add return air filter on living space side, if one is removed on "Renovation " side.
Obviously, change the filter(s) every other week or As Required.
[Edited by dan sw fl on 07-14-2005 at 03:49 PM]Designer Dan
It's Not Rocket Science, But It is SCIENCE with "Some Art".

Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities
-
07-14-2005, 03:49 PM #3
Banned
- Join Date
- Aug 2002
- Location
- Office and warehouse in both Crystal River & New Port Richey ,FL
- Posts
- 18,836
It's not the best thing to do.
The fan supplies/blows about 2000 cfm out and reurns/pulls the exact sme amount back.Separating it with visqueen makes this difficult,but as long as it moves enough air thru the system ,your ok ,as far as not damaging the equipment.
But,dust being pulled back can clog the wet A/C coil very quickly,change filters often,consider a "better " filter.
With the improvements you are making,insulation,window,upgrades ,if any,will llikely men ,the 5 ton may be oversized when you are finished.So it's fate may not matter,as it may need to be replaced.
-
07-14-2005, 03:52 PM #4
Regular Guest
- Join Date
- Jul 2005
- Posts
- 171
I am a remodeler and we do this all the time. We tape filters to all registers on the dirty side (not just returns) to keep dust out of the system. We use the smallest available pleated paper "furnace filters". If the dirty side is open to the outside (like when putting an addition), it's tough to get any cooling anywhere when it's 100 degrees outside, so we put up temporary walls. We use 2x4s and plywood, screwed together. They disassemble easiliy and can be reused for the rest of the project.
-
07-14-2005, 04:19 PM #5
Regular Guest
- Join Date
- Jun 2004
- Posts
- 69
Thanks everyone-
I will reduce vents on the remodel side and look into adding filters on diffusers. No return air to worry about on remodel side. Also, I did install a 5 inch Merv 6 filter on the system and will check it every couple months rather than annually.
Regarding system size - several bids were for 5 ton system. Yes, added dual pane windows but exterior walls are made of adobe - maybe R7-R10? No one knows for sure... Also, lots of windows, several windows and 8 ft and 6 ft slider facing east. Very nice views facing east - no intentions of replacing walls are loosing views
Thanks again!
[Edited by kuma on 07-14-2005 at 04:27 PM]
-
07-14-2005, 04:45 PM #6
Regular Guest
- Join Date
- Feb 2005
- Posts
- 344
Remodel
You are thinking right. The filters on the supply registers is not a very good idea though. Too much restriction of the blower. You may end up with a frozen coil.
Good luck...
-
07-14-2005, 04:52 PM #7
Professional Member
- Join Date
- Nov 2000
- Location
- Waco, Texas, USA
- Posts
- 6,153
spray your filters down good with cooking spray and replace weekly. you should be fine
"And remember my sentimental friend......that a heart is not judged by how much you love, but by how much you are loved by others" - Wizard of Oz.
-
07-14-2005, 06:08 PM #8
No one can say for sure if your hurting the unit or not from here without knowing the airflow. Have it checked to be sure you are running at least 80% of nominal. Just closing a register doesnt mean its going to go soewhere else, too much restriction will lower flow thorugh the unit. Closing off registers raises your static and adding a 5" filter isnt helping. Have it looked at.
-
07-14-2005, 06:59 PM #9
Regular Guest
- Join Date
- Jun 2004
- Posts
- 69
Ok - so lets say that its running below 80%... whats the major concern - over working blower motor or freezing coil...or? If I only cool house to 80 I cant imagine freezing coil? Where I live the AC runs only a few weeks during the summer. Its never on continuous from July through Sept. Just turned it on a couple days ago for the first time this summer.
[Edited by kuma on 07-14-2005 at 07:04 PM]
-
07-14-2005, 08:33 PM #10
take media filter out weeky to inspect, blow out as needed. especially if doing any sheetrock or sanding. amazing how fast that stuff can plug a filter.
-
07-16-2005, 07:54 PM #11
Regular Guest
- Join Date
- Jun 2004
- Posts
- 69
After running the AC for a couple days I notice its not nearly as efficient in cooling. I ended up cutting two 20x30 wholes in the visqueen and attaching two filters in those wholes. I realize the filters are adding some resistance although the ac is definitley working better now - drawing more air, cooling faster... visqueen not being stretched like a sail
Hopefully the filters will keep out most of the dust from the construction side.
I am curious though about a question I asked earlier:
"Ok - so lets say that its running below 80%... whats the major concern - over working blower motor or freezing coil...or? If I only cool house to 80 I cant imagine freezing coil? Where I live the AC runs only a few weeks during the summer. Its never on continuous from July through Sept. Just turned it on a couple days ago for the first time this summer."
Thanks again!
-
07-16-2005, 08:55 PM #12
Banned
- Join Date
- Nov 2000
- Location
- Coastal Georgia
- Posts
- 34,902
My cousins girl friend in less than a year totally wrecked a new air handler I installed by remodeling the inside of her house after I did a change out.
-
07-17-2005, 12:09 AM #13
Regular Guest
- Join Date
- Jul 2005
- Posts
- 171
OK, what happened? I am just as curious as Kuma. How did the remodel wreck the air handler?


Reply With Quote