Absurd pricing...oversized HVAC...

If you are going high eff furnace, than a 60 KBTU furnace should be fine.

What size AC was quoted?

If basement has no supply registers, then is it heated? Is basement finished living area?

I would not accept an Evolution furnace without an Evolution controller.

I would insist on a load calculation both heating and cooling.

IMO

Thanks for getting back to me, I am getting additional quotes to compare.

It looks like the AC size is 36,00 BTUs according to the above, not sure about tonnage.

The Lennox quote I got quoted a 90k BTU furnace as well, so there may be a reason they are quoting that size. The Lennox dealer went through the house and counted registers and returns, and the Bryant dealer only looked at the trunks in the basement, but does a lot of work on the homes in my neighborhood so is very familiar with the setup.

Any additional input is much appreciated.

A ton is equal to 36,000 BTU. The AC sizes you have been quoted would be 3 tons.

Most HVAC contractors are either too lazy or do not know how to do a proper load calculation. They use rules of thumb they invented. This usually results in over sized equipment. That is the reason you are getting the sizes your are being quoted.

You the homeowner pay for larger equipment and higher heating and cooling bills. In addition you will be uncomfortable most of the time.

Bryant Evolution is the same as Carrier Infinity. It is excellent equipment assuming it is sized and installed properly.

To correct Mike, 12000 BTUs equals 1 ton.

IMO

It seems the harder I try to get type the right numbers, the more mistakes I make. I stand corrected.

Thanks Mike and Tigerdunes, I really appreciate the responses. What exactly would be involved in a proper load calculation? I tried searching on the internet and found lists such as this:

The local climate
Size, shape, and orientation of the house
Insulation levels
Window area, location, and type
Air infiltration rates
The number and ages of occupants
Occupant comfort preferences
The types and efficiencies of lights and major home appliances (which give off heat).

No one has even looked at items like that. They seem to all be counting the registers or source trunks and estimating based on that. I have a few more estimates coming so we will see what happens. Any tried and true way to know you are getting a proper load calculation done or a definite way to know you're getting a good HVAC installer using proper procedures?

Thanks in advance!

Below is a link to HVAC Calc. It is software you can use for the load calculation. The homeowner's version is $49. I have not used it myself, but others on this forum have commented it is easy to use and accurate.

The number of registers and the sizes of duct work is important. It but it has no bearing about the heat gain or loss of the building. Duct sizes and air flow flow are another calculation which even fewer HVAC contractors will do.

Here is a link that might be useful: HVAC Calc

Thanks Mike! I had two more installers come out, both did a load calc, one specifically mentioned manual J. One came back with the same sizes 100k and 3 ton, saying I was on the fence due to poor insulation (none in the walls), so better to size up than down. The other is getting back to me earlier in the week, but said he thinks it will be closer to 2.5 ton, didn't estimate for the furnace yet, but thinks what is in there is oversized.

One of the problems is that the equipment they were quoting doesn't come in half ton sizes. Would it be better to size up or down in that sitaution?

You will find 2-stage equipment only come in whole ton sizes. I had a similar issue with my second floor condenser. The load calculation came out to 2.4 tons. The contractor quote a single stage 2.5 ton, or a 3 ton 2-stage. I was worried about being over sized with the 3 ton but I really wanted the 2-stages. So far it has worked great. The AC usually runs on low stage and keeps the humidity around 40%. On very hot days it will go into high and cool the upper floor fairly quickly whenever I do a set back.

Once you have the load calculation then you have to compare it to the actual output of the units you are considering. Most 2-stage units have a 30/70% split on high and low stage. You normally round up to the next size. I would not round down unless you are very close to the estimated load.

Also consider if you like to big gatherings in your house during the summer. It is nice to have some extra capacity for those situations.

Thanks Mike, you have been very helpful. I will see what the second estimate comes back with. So far, everyone seems to be around that 100k furnace and 3 ton. One person mentioned that due to the age of the home, they don'd recommend a 2 stage because my second floor will not cool sufficiently.

Additionally, 2 of the companies said due to the age of the home, they would rather see me get a less high end unit and spend the difference on sealing the home better and better insulating the attic. The home was built in 1953, no insulation in the walls, brick and cinderblock walls.

The advice from the dealers is nonsense. Start with a load calculation for both cooling and heating. All I see is guessing which will hurt you in both operating cost and comfort. Then go with equipment selection.

I personally would want a correctly sized two stage high eff var speed furnace correctly sized with the right controller/thermostat. Where will furnace be located? Close to ext wall for venting? Then an AC condenser minimum 15 SEER rated with best matching coil.

IMO

I have to agree what these guys are telling you makes no sense. Adding more insulation is good advice, but don't rob Peter to pay Paul. You can always add more insulation when the funds are available, but you are not going to upgrade your HVAC system again in a few years.

Ideally you would first upgrade you insulation then size the HVAC equipment based on the new insulation values. It may turn out even with the upgraded insulation the equipment sizes may come out the same. You would see this as part of the load calculation.

Has anyone done a load calculation yet?

Thanks Tiger and Mike. The furnace is located in the basement, close to the exterior wall where the AC lines come into the house.

Two people (both carrier dealers) have done a load calculation, both measured everything, counted windows, looked at sun exposure, etc. One put it into the computer and one had a sheet he was marking off. I can pry further to find out definite details, the one claimed it was a manual J came out with 100k BTU furnace and 3 ton AC, he claimed due to lack of insulation in the walls.

The highest line of high efficiency he quoted, among many other options at all different price ranges:

Infinity Series 100,000 BTU 97% A.F.U.E. modulating gas heater
2 stage 17 Seer R410A 3 ton condenser with matching coil

The other hasn't come back yet, but said I'm currently oversized and 105k BTUs and 3 Ton. One of the problems they both said is that a lot of the units don't come in half sizes.

I am the type of person that really frets over these things being right, so I am getting three more estimates this coming Friday.

Thanks again for all of your help, any additional thoughts of advice would be much appreciated.

Marking off the sizes of rooms on a sheet of paper is not a proper load calculation. One of the contractor who came to my house in 2009 did this. I still have his "guesstimate" sheet. He did not even bother to measure the rooms.

You are doing the right thing by gathering information and asking questions.

Thanks Mike. These guys definitely measured the rooms, took down the number of windows, sun exposure details, and a few other things, so I will see what the second guy comes back with.

Just got another two estimates back, both going 3 ton on the AC. I asked why and one said lack of insulation, the other hasn't gotten back to me yet.

I have three more scheduled for this Friday, will see what they come back with.

This just keeps getting more confusing...

Also, all of my quotes are above $10k including humidifier and a filter media air cleaner, except one which is for Bryant Legacy equipment which came in around 7k, using existing thermostat (20+ years old) and existing refrigerant line and not including humidifier and media air cleaner, as well as chimney lining.

This post was edited by Blake686 on Tue, Oct 22, 13 at 21:06