Heating/cooling in a new DW

[Kevin S.]

In the process of comparing two almost identical homes at 2 dealers, I was calculating heat loads for the homes to determine the benefits of 14/11/28 over 11/11/19 (floor/wall/ceiling) insulation. I say identical because they ARE the same models with only a few variations, one being the upgraded insulation. Anyway, the dealer with the better insulated unit will be installing a 3.5 ton unit while the other says he will be putting a 4 ton in.

Both programs I use for calculating heat loss/gain call for less than 2 tons and I'm right at 2 tons with a "safety" factor of an additional 25%. Am I missing something with manufactured homes, such as the duct size and return/intake size not being standard? Or are the dealers just going with some standard sizes that seem to be OK for them?

Just so you know, the homes both have thermopane, low-e windows, fully wrapped in OSB and outer wrap, etc. In other words, they are fairly "tight". And the homes are 28x62.

I'd like to believe my HVAC programs to some extent because I have used them successfully in the past when sizing units for a new home I built about 4 years ago (that thing cost me my marriage so that is why I'm looking at manufactured housing now *grin*). I also do not want an over-sized unit because of the problem of higher energy costs, less humidity removal potential, etc.

Oh, and I live in Central Alabama .

Thanks for any advice!
Kevin

[rmurray]

If energy savings is important to you...Check out www.energystar.gov .. be sure to buy an enrgy star ready home...On this web site you can search for builders in your state that are serious about energy savings.....

Each of these homes will have a heat loss info on the data plate mounted inside the home..It will quote the maximum size unit to achieve a good result with the lowest enrgy costs....Time to get your home...

[unknown]

you might also take your questions to your local utility company, and inquire about any rebate program they might have going on at the time.