A/c ?

[Costactc]

Just a quick question. I'm changing my central air conditioning unit and was wondering if it makes a difference between electricity and gas for hookup. Are there different units that are compatible with one or the other or are they good with both?

[torpainter]

whether you have gas or electric furnace is not a consideration Costa

[Costactc]

Thanks Tor, found a great deal but not quite my specialty.:thumbsup:

[torpainter]

I just replaced mine last year

[eyeQ]

check with rob31us for advice :yes: in the long run i think its cheaper to replace both as one brand..

[Costactc]

What do you mean by both Q?

[Mr Hanky]

If you are refering to just changing the outdoor condensing unit.The old one is most likely R22 refigerant and depending on if you are in the us or canada will determine what refrigerant is presently banned.Canada only has 410A refrigerant units available now,which if thats what you purchase you will have to change the coil in the furnace plenum as well.410A condensors are not compatable with a R22 evaporator coil.Line set size is also a factor you cannot use smaller lines,expecially at a distance over 15 ft.When replacing components its best to change Condensor/evaporator and lineset to ensure a full life out of you new system.The seers are much higher now that you can read the name plate on the condensor and use a smaller breaker then the previous 30/40 AMP double pole setup.Good luck with your new project costactc.:laughat:

[bc420]

hey friend i install these thigns whts important is where u live for one how cold do u get if u r below minus -15 u will want a gas combo if not the more cost efective way is to go with a heat pump revers the freon to produce heat works amazing through spring and fall avrage bout 40 to 50 $ on hydro vers 100$ on gas. basically running ur a/c in the fall lol but the heat pumps do not work so well in the cold cold the elictric heat elements kick in below -10 or u can get speacil sensoirs for bit colder only here in canada .... for the power secondary heat most comon 15 kw to 20 kw so there u have it the ups and downs beleave when i say i know i have put in over 70 of these combos very popular in canada southern areas best of luck to u oo one more thing for name brand sujestion only (goodman)

[Costactc]

I'm planning on picking up a Ducane 3 ton, 36000 btu unit with its coil. I live in quite a cold climate and already have a high efficiency furnace which is only 5 years old so heat pump would be a no go. I presently have a 2 1/2 ton unit which runs all day when it's hot outside. I've brought in experts and they all say the unit is running fine. My previous 2 1/2 ton unit used to kick in for about 5-10 minutes and shut down but not this unit. I figure to save about $200-300 annually which will have itself paid off in 5 years with the present unit.

[eyeQ]

What do you mean by both Q?i mean same brand name for furnace & a/c:)

[bc420]

sounds good for a split system getting the best of both i have this in my house did not want to replace both furnace and a/c so put a A coil inside with a heat pump a/c combo works awesome ! i am about 80,000 btus on each of my furnaces i have 2 1up stairs and 1down stairs a/c unit is 70,000btus and i still have gas for when its cold plus a 12 son tht does a great job with fire wood lol theres my savings ..but here is the savings i have 3800square feet and it only cost me 70$ to 90$ a month to heat my nebours whos stuff is antquie runs him bout 120$ a month 2500square feet on this note any who r interested in both u get one or the other( heat pump a/c elictric)or gas combo a/c)no heat pump, unless u do a split system and a system like this is a few bucks but well worth it in the long run

[Costactc]

Thanks for all the info and help peeps, I'll be ordering my new unit next weekend- should keep my 1,750 sq. ft. shack nice and chilled at a much better savings.

[dells]

I'm planning on picking up a Ducane 3 ton, 36000 btu unit with its coil. I live in quite a cold climate and already have a high efficiency furnace which is only 5 years old so heat pump would be a no go. I presently have a 2 1/2 ton unit which runs all day when it's hot outside. I've brought in experts and they all say the unit is running fine. My previous 2 1/2 ton unit used to kick in for about 5-10 minutes and shut down but not this unit. I figure to save about $200-300 annually which will have itself paid off in 5 years with the present unit.


Thanks for all the info and help peeps, I'll be ordering my new unit next weekend- going to run me about $1400 for the unit and coil but should keep my 1,750 sq. ft. shack nice and chilled at a much better savings.

if going with a 3ton unit on a 1,750sq ft home duct size will play a factor, if your duct size is to small to carry the airflow you will run into issues and you may not find yourself saving too much, a 2 ton and possibly even a 2.5 ton unit should be more than sufficient for a 1,750sq ft home, bigger is not always better when dealing with central air...

[Costactc]

My present unit is 2.5 ton but works all day to try to get the temp down. Do you think that the ducts could use a cleaning?

[Terryl]

My present unit is 2.5 ton but works all day to try to get the temp down. Do you think that the ducts could use a cleaning?

There would have to be a ton of junk in the duct-work to cut down on the air flow, how old is the duct-work?

Some of the older stuff was metal wrapped in insulation, some of the really old stuff wasn't even wrapped.

My sister had a heating/cooling problem, I found it to be a bad layout in the air return, we added a second return in the family room and the cooling and heating in that general area improved 30%.

Also it depends on where the ducting is, if it's up in the super hot attic then you can loose out on some cooling, (and heating during the winter) and if you have just the metal duct with wrapped insulation on it, and it's up in the attic then you can loose even more.

In my old house in the SF bay area, I replaced the old metal ducting up in the attic with the plastic fully insulated ducting, and it made a big improvement.

My theory on AC is that the return should always be bigger then the supply, you get better air flow.

If you have the metal stuff, you can add a second layer of insulation to it, it's a big job, but it would be worth the effort, more insulation in the attic or under the floor helps to.

[Costactc]

All in the basement Terryl and only 5 years old. I might look into adding a return.

[Costactc]

I also noticed that I have 2 returns on the main floor, one of which is being used as a vent instead of a return, could turning this back to return help?

[JCO]

Costa there are 12,000 BTU Hr per ton of air conditioning.. I have a feeling your existing unit is low on refrigerant or the coil and ducts are blocked or very dirty.. Because that cooling capacity is close to being ideal for a moderately well insulted home of that size.. A good cleaning of the ducts and the cooling coil and a check up of the refrigerant level would be a good idea before replacement.. While your at it clean out the heating side also..:thumbsup: If its gas fired on the heating side make sure to clean the heat exchanger on the inside as well as the orifices of the burner with a brass brush..

[Costactc]

I think I'll have it checked out before ordering another one.

[Costactc]

Thanks to all the fine peeps and techies that posted. The a/c unit needed a major hosing down and the fan blower for the cooling system in the furnace was not set to high- looks like I'll be holding on to this unit and saving lots of $$$ in the process.

[Terryl]

On most systems there usually is only 1 return, and that should be centrally located, so it draws air back from all sides of the house.

Now if your house is laid out longways, 1 return won't be enough, that is why I added a second one at my sisters house, it drew air in at the end of the long family room, thus pulling in the heat/cooling to that room a whole lot better then the original layout, we are thinking to add a third smaller return to the master bed room, and cut back on the central main returns air volume, this should improve things a bit.

[Costactc]

I noticed a second return in one of the bedrooms, I think I'll be good.

[bustamante1974]

In reality you should have had a proper heatloss/cooling load calculation for your house completed. If your 2 1/2 ton unit was coming on and shutting off it was probably short cycling...OVERSIZED...like my furnace and AC were...not now and no short cycling...

[Costactc]

Unit was turned on mid-May and it's been fine, no issues like the last 2 years. Considering humidity level will be over 40c tomorrow, I'm staying indoors and chillin.

[aquadave]

If you have NG it's much cheaper to heat compared to propane or elec. If you live above Virginia then either NG or propane is cheaper and better to heat than heat pump/elec. That's the bottom line