Any home AC pro's around

[Marc Mulhern]

Hey everyone, just thought I would throw this out and see what happens. I am looking to add central air to my house. I don't have duct work or anything, have radiators for heat, so I know depending on the route I go, it can be costly. I spoke with someone who feels I can save 50% of the money by just having the duct work run on the second floor of the house and that will cool the first floor enough to make it livable. The estimates I've received to add it to the entire house is 15k, so 7k is appealing to say the least.



Anyone ever heard of cooling the second floor and the air 'dropping' to the first floor to cool it off?!



thanks,

Marc

 

[ivan spielfogel]

I am not an expert, but I have lived in a home that had 2 seperate heating/cooling systems one up and the other down. This was a forced are system for both heating and cooling. In the summer I would run the A/C in the upper unit to cool the bedrooms and the air would settle to the first floor.

In the winter I would reverse the process. The hot air would rise to the bedrooms in the evening, but the lower floor would be comfortable during the awake hours, the bedrooms would be cooler but we generally used some sort of bed coverings. I live in southern california, so our temperature change is general a 30 degree change morning to night year round. Winter never cooler then 40F then 70F during the day, summer sometimes 100F but 70F at night, and low humidity. I do not know you homes layout, but if you have central hallway, you could drop ceiling in hall to 7Ft and have room for your ducts to feed the rooms. You could sacrifice a portion of a closet for 1st to 2nd floor transition of A/C feed. The duct requirement,, that is cross section area, for A/C is twice that of heating for specific BTU. Hope that helps

 

[Robert Hermanson]

Marc,



I see you are in PA. Hmmm, cast iron radiators, must be an older house. To do this properly you should have the main return air duct located in the space without air so it will draw the "cooler" air thru the unconditioned space. There are sooooo many variables with this, such as insulation in your home, shade or direct sun, etc... If the space is unconditioned the ductwork can sweat (condensate).



Comes down to the almighty dollar..... as allways.



Rob

 

[Kevin Palmer]

I am the man you are looking for !!!!!!!!!!!!



I did the EXACT thing your wanting to do.



I have ONLY electric baseboard heat. I had NO duct work in my home of any kind.



I inherited some money from my grandmother when she passed away. So, I figured my grandmother would want me to be comfortable in my home.. LOL



I installed a gravity type system, which, basically means 1/2 of the unit is in your attack and the other half outside like all other systems so that the condenser and what not work as designed.



As far as the duct work goes, I paid an AC guy to come to my home to tell me what I needed as far as size of unit as well as his best suggestion as to where outlets should be. With that information he was able to tell me the diameter of the ductwork based on the location it was dumping to and what not.



I did run ducts to both floors (I have a 2 story home with 3200 square living feet).

The upstairs was not to bad as I was in the attic and was able to cut the holes and pretty much run the ductwork.



The down stairs was a bit of a challenge, but, I am glad I did it as my home is perfect. No hot spot and no cold spots.



To get to the downstairs, I removed all the stuff from the closets in the area that I needed the duct to be below. I cut a hole in the ceiling of the closet, ran the duct along the wall of the closet, marked and cut the floor of the closet, cut the ceiling of the down stairs and hooked up all of the grate work and what not.



Once I had it all ready to go, the AC guy cam back and hooked up all of the electrical and all components. We made sure all was working well and he was on his way.



I then built a mini stud wall around the ducts in the closet and then put up a 1/2 plywood wall to finish it. I painted it the same color as the closet and then put it all back together.



It looks perfect, you can not tell that I did what I did.



One of the reasons I recommend getting advice on the diameter and size of the pipes is, in my one living room, (I have two), it is very large and I only had one location I could get a tube to.

He measured it all out and told me I would have to have a 14 inch tube and grill to make it all equal out as far as the the pressure in the tube compared to the other tubes and still get the amount of air I need into the room to do the job.



Well, he must have been right as like I said, my home is perfect.



My return is in my upstairs hall way which helps in the cooling system as the air dumps all over including downstairs and then is sucked back up through the living spaces and into the cold air return.



Over all, it took me a week to run the ductwork and I worked hard to do so. I spent 2500 for everything.



I would do it again in a heart beat, well worth it.

 

[Marc Mulhern]

Ivan...that is what the guys were telling me is the cold air would settle to the first floor and cool it enough to make it comfortable. My first floor isn't insulated very well and the second floor only has it under the siding outside (for now).



Rob, I live just outside Philly in Ardmore and you are correct, the house was built in 1920! and they used true 2x4 lumber. I don't get direct sunlight in the winter but get some in the summer.



Coastiejoe....that is what I was thinking of doing as well. I am handy enough that I can run the duct work down the walls and have them finish the install. Like you said, knowing the construction of the house, I may only be able to get one feed in some of the rooms. I'm not 100% I can get anything to the breakfast room.



Like you guys said.....it comes down to the dollar!!



Marc

 

[Todd Z]

They also make ductless Split systems....

Check them out...



Todd Z

 

[Marc Mulhern]

Todd Z, are you referring to the high velocity units that have 4" tubing or is there another system out there?



marc

 

[Ron N]

No, I think he is talking about the systems that have an outdoor unit and one indoor unit that fits against the wall. It blows cool air in the room, It is also available in multi room units. You install the unit and run the hoses to the inside unit thru a hole in the wall. These type are great if you have no area to add ductwork. They are more expensive, but it is like having a window a/c with out the window. If you are looking only for cooling, yes the cool air will travel down stairs. AS the air cools it gets heavier and transfers down. It is basically secondary cooling. The area's closer to the stairway will be cooler. Do you have attic area upstairs to add ductwork? Are the ceilings in the first floor excessible? The last thing is you can add the return air to the furthest part of the house"from the stairway" on the first floor. This will pull more air down stairs. _Ron

 

[Marc Mulhern]

blackhat, I would have to cut holes in the floors to get to the ceilings but I am o.k. with that as I would like to hide it all in the closets Coastiejoe mentioned. I think I know of the sytem you and Todd mentioned, I've seen something along the lines that you mentioned on-line a while back. My attic is large enough to finish it and we are intending on doing that in a few years, so I am guessing there should be enough room to add ductwork.



thanks again everyone, I am going to talk with the A/C guy about running it on the second floor and see where we go from there.



Have a great weekend and thanks again!!



marc

 

[Scott Tanner]

I would put in 2 systems, a fan coil in the attic, and one in the basement. Run 2 condensing units, run flex duct to registers in the ceiling, or floor, and flex your return. In PA, you're not going to run it 24/7, so the flex duct is ok.. (Flex duct uses more power to push the air though it, but is cheaper and easier to install).. This way you have 2 zones, so you're not cooling the whole house if you don't need to. If you do not have a basement, then a closet, as mentioned above works good. Split packaged units are nice, but they are fugly hanging off the wall, and are way expensive. A ton and a half fancoil/cond unit will run somewhere around $500 if you can buy wholesale.... JMHO (BTW, I work and teach in the industry)

 

[Marc Mulhern]

thanks STanner. I am going to mention this stuff to the A/C guy and see what we can work out. I would like to do some of the work and he can do the finish work. I figure this can be good for him as he spends little time at the house but still make a decent amount of money on the deal.



marc

 

[Thomas Rogers]

STanner, a friend of mine bought an old browstone in Center City Philly and went with a similar setup. That's a cheap way to go.



One thing to note, though, however, don't underestimate the use that an AC unit will get in the Southeastern PA region during late July and August. I live in that area, and our whole-house AC is turned on 24x7 from late June through mid Sept...sure it isn't running 24x7, but it is on and off all the time during those months.



When I lived in Central NY it was uncommon for people to have whole-house AC, because even in the warmest months (more like weeks up there) of the year, it still would get cool during the nights to where you could open windows and use a whole house fan and attic fans to cool the house down and make it bearable again for the next day.



In Southeastern PA it is quite common for weeks (and months) on end for the evening temperature to not drop down much below 80 deg.



TJR