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  • Suggestions on new A/C unit

    My son is in need of a new rooftop A/C on his house. The house is 1100 sq feet and has single payne casement windows and is block. Those 2 alone give it 2 strikes against being anything close to efficent.
    The unit will be a rooftop 3 ton,13 Seer unit and he has gotten 2 prices so far.
    One was $5,600 and another was $4,400 for a Rheem or Ruud from one of my customers that i'm building cabinets for right now.
    We also saw an add in the paper yesterday for a TempStar installed for $2,695 complete. This is the exact same model and same company that did my own house 11 years ago! LOL

    We are getting conflicting info on a few things and thought i"d ask here.

    We have been told that the new 14 or 15 seer units are actually not as good as the older 12/13 seer units. Something about getting too cold too fast and cycling too often and not getting out enough moisture. Any truth to that? (It gets really really hot here and the summer humidity is tough too.)

    My son wants to install a gaspack as he already has gas in the attic and this will also free up some needed space when he pulls out his old antique gas furnace.
    Others say install a heatpump as they are better and more effecient with lots less parts and a smaller overall cabinet. Our thinking is running the compressor for a/c AND heat is going to be expensive and will shorten the life of the compresser drastically.

    My unit is a heatpump but I don't use it for heat,,,,,ever!!!! (it was cheaper than a straight a/c at the time.)
    I have a good gas furnace and we just like gas heat! My a/c has worked almost flawlessly for 11 years now. Only had one contactor go bad and one circuit board die. Not too bad for all these years.

    My brother in law says that R22 will be off the market by 2008 and banned not long after that????? Is this true? ( I guess Dupont needs to screw us again?)
    He says to install a new whizz bang 19 seer split system that uses some new product and beat the rush! LOL (about 8 grand!!!)

    Are the R22 units getting cheaper and cheaper because they are going to be dumped/banned soon?

    This is our sons first house with his new wife so they may not be there for a long long time, but atleast 3-5 years anyways.

    Please help us sort out this mess! Any and all suggestions and revelations are much appreciated!

    Mark and Son!
    Last edited by The Wood Meister; 07-15-2007, 08:43 PM.
    Congratulations to Mr. "the sky is falling" Al Gore, nominated the new Village Idiot!

  • #2
    Re: Suggestions on new A/C unit

    Originally posted by The Wood Meister View Post
    My son is in need of a new rooftop A/C on his house. The house is 1100 sq feet and has single payne casement windows and is block. Those 2 alone give it 2 strikes against being anything close to efficent. Is this a split unit we're talking about? The unit will be a rooftop 3 ton,13 Seer unit and he has gotten 2 prices so far.
    One was $5,600 and another was $4,400 for a Rheem or Ruud from one of my customers that i'm building cabinets for right now. Have either of these companies done a heat load calc (manual J)for the house? Both units a good, not the best but good. How do they know 3 ton is big enough?
    We also saw an add in the paper yesterday for a TempStar installed for $2,695 complete. This is the exact same model and same company that did my own house 11 years ago! LOL Never heard of that brand.

    We are getting conflicting info on a few things and thought i"d ask here.

    My son wants to install a gaspack as he already has gas in the attic and this will also free up some needed space when he pulls out his old antique gas furnace.
    Others say install a heatpump as they are better and more effecient with lots less parts and a smaller overall cabinet. Our thinking is running the compressor for a/c AND heat is going to be expensive and will shorten the life of the compresser drastically. Not true. If you go with a heatpump, I like them, then you will have to most likely change your ductwork. If nothing else a manual d calc will have to be done.

    My unit is a heatpump but I don't use it for heat,,,,,ever!!!! (it was cheaper than a straight a/c at the time.)
    I have a good gas furnace and we just like gas heat! My a/c has worked almost flawlessly for 11 years now. Only had one contactor go bad and one circuit board die. Not too bad for all these years.

    My brother in law says that R22 will be off the market by 2008 and banned not long after that????? Is this true? ( I guess Dupont needs to screw us again?) It is getting banned but I can't rember the particulars. Don't be alarmed though. You can still get R-12 through certain routes and that was banned years ago.
    He says to install a new whizz bang 19 seer split system that uses some new product and beat the rush! LOL (about 8 grand!!!) Is it 410A? If they're only staying in the house for 5 years they might not get their money back. There are 22 systems that are high effiency.
    Are the R22 units getting cheaper and cheaper because they are going to be dumped/banned soon? Yes, but not that soon. Don't worry, r-22 won't be obsolete for another 15 years

    This is our sons first house with his new wife so they may not be there for a long long time, but atleast 3-5 years anyways.

    Please help us sort out this mess! Any and all suggestions and revelations are much appreciated!

    Mark and Son!
    Here are some other thoughts, don't shop by brand, shop by installer and warranty. Nate certification will help steer you towards a quality shop. Last, a heatpump can be used in cold climates but they need to be designed for makeup heat(electric heat strips) properly. Heat from a hp doesn't feel the same as gas so don't have unrealistic expectations.
    Buy cheap, buy twice.

    Comment


    • #3
      Re: Suggestions on new A/C unit

      Thanks for the input GJ....

      The unit will be an "all in one" roof top.

      No one has been to the house as of yet. We are still in the "shopping" stage right now. Out here, unit size is figured by square footage. He's been told that for 1000-1100 sq ft, a 2 1/2 ton is called for but a 3 would do a better job since he, like me, keeps his house in the low 70's in the summer and atleast 70 for sure at night! Yea, it's a little expensive to run but we just can't sleep in a warm house.

      If he goes to a heatpump, why would he have to change the duct work? His return and suppy exit the roof and go right to the old and soon to be new unit. What needs to be different? and why?

      Mark
      Congratulations to Mr. "the sky is falling" Al Gore, nominated the new Village Idiot!

      Comment


      • #4
        Re: Suggestions on new A/C unit

        Originally posted by The Wood Meister View Post
        Thanks for the input GJ....

        The unit will be an "all in one" roof top.

        No one has been to the house as of yet. We are still in the "shopping" stage right now. Out here, unit size is figured by square footage. This is wrong on so many levels!! The principles of ac apply to Az just like they apply to Va. He's been told that for 1000-1100 sq ft, a 2 1/2 ton is called for but a 3 would do a better job since he, like me, keeps his house in the low 70's in the summer and atleast 70 for sure at night! This guy is a hack, oversizing a unit will reduce how effective it takes out the humidity. He might a guessed right but that's all he's doing, guessing. Yea, it's a little expensive to run but we just can't sleep in a warm house.

        If he goes to a heatpump, why would he have to change the duct work? His return and suppy exit the roof and go right to the old and soon to be new unit. What needs to be different? and why? A heat pump provides heat of only about 100 deg tops. Gas heat essiantially scorches the air (I forgot the temp) and is much more forgiving of poor duct construction and design. That's why heat pumps are often referred to as "cold heat". AC techs are in the comfort business. There are many variables you have to take into consideration to get that. This guy is missing the biggest part. Go elsewhere. You get what you pay for. Mark
        I wish you best of luck, sleep on the desicion, wait till RuudAC gives his opinion on this also.
        Buy cheap, buy twice.

        Comment


        • #5
          Re: Suggestions on new A/C unit

          Well, since we've gotten so many differing answers locally, I thought i'd ask here for some advise. We will wait a while and try to figure it all out.


          What is involved in this calculation that you mention? Never heard of it, but then again, I'm not an A/C guy either! LOL

          Mark
          Congratulations to Mr. "the sky is falling" Al Gore, nominated the new Village Idiot!

          Comment


          • #6
            Re: Suggestions on new A/C unit

            Both calcs are pretty lengthy. I have a computer based calc that does it for me. Cost 650.00. It's not a simple a+b=c. Both take many factors into consideration(color of roof, insulation, wall material, which way your house faces, etc.) the manual d does the same thing in principle. It sees how much cfm you have, your friction rate and coupled with some other things tells you duct sizeing and makes sure you're designing it right. A 3 ton is not always a 3 ton. You have to look at sensible btu(what you feel) and latent btus(humidity taken out). Both go hand in hand. When this gets done you should get a printout of the calculation. Its usually 4 pages at a minimum for j manual and 3 pages for d manual. Find someone whose nate certified, pay them what they want and you'll get a better product in the end.
            Last edited by gear junkie; 07-16-2007, 07:16 AM. Reason: forgot something
            Buy cheap, buy twice.

            Comment


            • #7
              Re: Suggestions on new A/C unit

              GJ pretty much nailed it for you, Wood Meister.

              Load calcualtions will determine the exact needs of the building. Wall construction, ceiling construction, window type and size, internal gains, shading, internal setpoints, and what direction the house faces are all important in equipment sizing. I dont always feel the need to do load calcs because I have done enough of them, I pretty much know what they are just by looking at the building.

              I'm not a huge Tempstar fan, but seeing that your heating needs are very minimal it might not be a bad choice. They still use a clamshell type heat exchanger. I have changed out close to 20 of them in the last couple years, and I'm not even a Tempstar dealer. The Ruud on the other hand uses a tubular heat exchanger. The builders model furnaces use a mild steel hx which I dont install, but the premium series furnaces have a stainless hx. This style hx has been in use since 1994 and I have yet to see one fail. I dont know which material they use for the small package units. Either way, if heating isnt a big issue, you cant really go wrong with either. At this point its more about the finding the right contractor.

              I wouldnt worry about your quotes being a half ton different from each other. Half a ton isnt enough to be drastically oversized. If you had a quote for a 2 and one for a 4, thats when it gets nerve racking.

              R-12 was banned years ago and I have access to more than I could ever use. I predict R-22 or a drop in replacement will be available for a long time.

              Comment


              • #8
                Re: Suggestions on new A/C unit

                Thanks to both of you for your insite.

                Is this calculation done by a specialist or by "any" A/C contractor? Is this something that is done at a cost over and above the A/C install or part of the whole deal? As you can see, i'm not up at all on A/C stuff! All I know is when it quits working and I get hot, I get ticked and cranky! LOL

                I can meet with my customer today and ask him some more questions on my sons A/C. He's been in the business here in Phx for over 35 years and has a very good rep. I kinda blindsided him when I asked about my sons house. I told him what I was told he needed and he just answered my question based on MY request. Like I said, we are still in the beginning stages of picking a contractor and unit. I guess there is more than meets the eye here! LOL

                Thanks again.

                Mark
                Congratulations to Mr. "the sky is falling" Al Gore, nominated the new Village Idiot!

                Comment


                • #9
                  Re: Suggestions on new A/C unit

                  Here is the lowdown on you question about R-22.
                  1. January 1, 2010 is the end of new equipment being manufactured with R-22 in it. The refrigerant can still be produced to service existing equipment.
                  2. January 1, 2020 is the end of chemical manufacturers being allowed to make the r-22. However any existing r-22, being either from recovery or stock piles, can still be used beyond the 2020 deadline to cease manufacture of it.
                  Hope this helps some.

                  Regards,

                  Comment


                  • #10
                    Re: Suggestions on new A/C unit

                    Originally posted by The Wood Meister View Post
                    Thanks to both of you for your insite.

                    Is this calculation done by a specialist or by "any" A/C contractor? Is this something that is done at a cost over and above the A/C install or part of the whole deal? As you can see, i'm not up at all on A/C stuff! All I know is when it quits working and I get hot, I get ticked and cranky! LOL

                    I can meet with my customer today and ask him some more questions on my sons A/C. He's been in the business here in Phx for over 35 years and has a very good rep. I kinda blindsided him when I asked about my sons house. I told him what I was told he needed and he just answered my question based on MY request. Like I said, we are still in the beginning stages of picking a contractor and unit. I guess there is more than meets the eye here! LOL

                    Thanks again.

                    Mark
                    Actually in bigger companies it's the salesman that does the design and calcs. This guy's been around for 35 years-he's probably doing something right. The reason why I say probably is because when I first started AC in Augusta, ga the company I worked for was nothing but hacks. I learned that later when I started going to school for it and saw how many bad habits I learned. That company was in business for over 20 years at the time and was augusta's biggest residential ac company. I like NATE certification because it's not a blanket policy like "master hvac tech" is. If the person you get is nate certified then he's got the certificate. Not a guy somewhere else in the company.

                    I'm a subcontractor and when I price an install I include that into the price. I used to list it as seperate but lost a couple jobs when the customer thought that was unreasonable when they wanted me to take the load calc out. Their mentality was"I have a 3 ton now, just put a 3 ton in". I now tell them I'm doing one but don't give a price breakdown. My thought is that I'm the expert, that's why the customer is paying me, their comfort in the end is what's important. I understand what's needed. The flipside is that I don't do a load calc, the customer is uncomfortable and they blame me. Besides, I can do load calc in 30-45 min.
                    Buy cheap, buy twice.

                    Comment


                    • #11
                      Re: Suggestions on new A/C unit

                      When I talk to him i'll ask if he does that. Hopefully he will! LOL

                      So the general consisis is a gas pack since the house is existing and cannot really be modified for a heat pump?
                      Congratulations to Mr. "the sky is falling" Al Gore, nominated the new Village Idiot!

                      Comment


                      • #12
                        Re: Suggestions on new A/C unit

                        In order for me to make a choice between a gas-pack and heat pump I'd need to know what you pay per therm for gas, the cost of electricity per kwh, and the exact needs of the house.

                        I'd sure think you can heat more efficiently with a HP instead of a 80% efficient gas unit. But, given the fact that your heating needs are so little, the added cost of the HP might not pay back in a reasonable timeframe. From here, it sure seems like a HP would be the way to go.

                        You only spend an average of 65 hours per year below 30 degrees. The recommended outdoor design conditions for Phoenix based of off temps recorded at LUKE AFB are 38 degrees in the winter and 107 in the summer. This means the temperature difference in the load calculations (based on 70 indoor) would be 37 in the summer and 32 in the winter. Just for comparisons sake, where I'm at is 91 and -4.

                        Comment


                        • #13
                          Re: Suggestions on new A/C unit

                          Boy am I glad someone clarified the R-22 issue. I get so tired of the misinformation about R-22 not going to be available. Heck, R-12 and R-502 are still around..definitely higher than 10 years ago but it's still there.

                          I personally know dozens of people with old showcars that have a jug of R-12 in case the a/c developes a leak, small grocery store owners with R-12 and 502, and some homeowners that have found jugs of R-22.

                          Go Bucks

                          Comment


                          • #14
                            Re: Suggestions on new A/C unit

                            Hey W/Meister:

                            Looks to me like you have some good advice. A load caluation can be done by any good HVAC Co. If you have some time, contact a local Comunity College that teachs HVAC and see if doing a load calculation would be something some insturctor could use as a project for a class.

                            This sizing by square feet has been around for a long time, but it is surely a good way to get a poor job. Too many vairables to trust this for the best way to heat and cool your home. (Also), if a system is much oversized it will not run enough to get out the humidity and you will not feel comfortable and you may have some mold and mildew problems in the home. Remember hot air holds more moisture even in AZ.

                            A heat pump might be a good choice, but I am not familar with weather in your area. Just as my rule of thumb, once the outside temp drops below about 40 degrees F the heat pump will now need a secondary heat source (such as heat strips) to supply enough heat to keep you comfortable.

                            As already stated by an earlier post, most consumers complain about a HP, they don't like the "cold heat". The main difference here perception.

                            A typical heat pump will bring in heat from the cooler air outside at about 95 F or there about. If 95 degree air blows across you skin which is about 98 degrees it feels cool. A furnace, gas or electric will heat the air to about 120 - 125 dgrees. This just feels warmer when blowing on ones skin.

                            Get a good contractor, and good luck,

                            P.S. Tempstar is the old Whirpool, Sears, brand.
                            Last edited by thepapabear; 08-18-2007, 04:47 PM.
                            thepapabear<BR>When a bureaucrat has a hammer, everything begins to look like a nail.

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                            • #15
                              Re: Suggestions on new A/C unit

                              T W M

                              Please update us on how things are going. Thanks

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