using square foot per ton basis

[Gopirates]

Are things changing so much that 600sqft per ton is not the standard for A/C any more? I know I am not taking in account the load calculation but I here of so much undersizing going on based on the SEER that in my thinking I thought that the SEER is only dealing with current usage. (Seasonal Energy Efficiency Rating) If an individual had a 2.5 ton 8 SEER it would be replaced with a 2.5 13Seer because the home insulation has not changed. An inquiry would be appreciated.

[BaldLoonie]

It never was a "standard" as construction quality and amount of windows varied as did outdoor temp. Around here, 600 sq ft/ton might work, in Arizona where they don't build the houses, especially older, like we do, might take twice that.

Only answer is an accurate load calc.

[Gopirates]

I do not know about Arizona but I do not think that will work here in NC

[pipefitter636]

Here in (The Detroit area) the rule of thumb is 600sf per ton on old construction and 800sf per ton on new construction. Not allways accurate. Best is a heat load calc.

[paul42]

Are things changing so much that 600sqft per ton is not the standard for A/C any more? I know I am not taking in account the load calculation but I here of so much undersizing going on based on the SEER that in my thinking I thought that the SEER is only dealing with current usage. (Seasonal Energy Efficiency Rating) If an individual had a 2.5 ton 8 SEER it would be replaced with a 2.5 13Seer because the home insulation has not changed. An inquiry would be appreciated.

Sqft per ton is useless.

My 2 ton 14 SEER Trane heat pump cools my 4,000 sq. ft of house quite well.

[hvaclover]

Here in (The Detroit area) the rule of thumb is 600sf per ton on old construction and 800sf per ton on new construction. Not always accurate. Best is a heat load calc.

Only hacks use those numbers. i am in the same area as you and don't know any independent who would stake their rep on those ambiguous numbers.

Are you in service or the fitting end of 636?

[HeyBob]

Square ft per ton.........hmmm..............let's use an example.

2000 sq ft home divided by 750 = 2.67 tons.

Now that house has an 18' great room ceiling, 10' ceilings everywhere else, tons of windows facing west, east and every which way, built in 1970, it just might need more than that.

That's why we do load calcs.

[hvaclover]

Square ft per ton.........hmmm..............let's use an example.

2000 sq ft home divided by 750 = 2.67 tons.

Now that house has an 18' great room ceiling, 10' ceilings everywhere else, tons of windows facing west, east and every which way, built in 1970, it just might need more than that.

That's why we do load calcs.

[hvaclover]

Square ft per ton.........hmmm..............let's use an example.

2000 sq ft home divided by 750 = 2.67 tons.

Now that house has an 18' great room ceiling, 10' ceilings everywhere else, tons of windows facing west, east and every which way, built in 1970, it just might need more than that.

That's why we do load calcs.

Robert just for kicks say there are no such thing as load calcs, what size does you hvac sense tell you?

[Airmechanical]

Sqft per ton is useless.

My 2 ton 14 SEER Trane heat pump cools my 4,000 sq. ft of house quite well.

that's a crock!



,

[Gopirates]

Only hacks use those numbers. i am in the same area as you and don't know any independent who would stake their rep on those ambiguous numbers.

Are you in service or the fitting end of 636?

Yes I am in service. I started out doing residential and now I am doing controls whether it is on the equipment or doing it through several types of BAS. I asked the question due to the reading I have been doing on this web site and other web sites and I have noticed the changes in sizing units verses what is generally taught in the classroom besides heat load calculations. Heat load calculations are how it should be done no doubt about it.

[hvaclover]

that's a crock!



,

yep assuming he had only a single furnace a two ton evap would restrictt the flow with out by pass dampers in the heat cycle.

[pipefitter636]

Only hacks use those numbers. i am in the same area as you and don't know any independent who would stake their rep on those ambiguous numbers.

Are you in service or the fitting end of 636?

I didn't say they were accurate did I!!! What did I say was the best method???

[Gopirates]

yep assuming he had only a single furnace a two ton evap would restrictt the flow with out by pass dampers in the heat cycle.

I know people who have smaller units in their homes even though they have quite a bit of square footage but the only way they get buy is by zoning. For what ever reason if the system should go full cool especially on all the zones they are in a mess. Unit will not keep up.

[pipefitter636]

Yes I am in service. I started out doing residential and now I am doing controls whether it is on the equipment or doing it through several types of BAS. I asked the question due to the reading I have been doing on this web site and other web sites and I have noticed the changes in sizing units verses what is generally taught in the classroom besides heat load calculations. Heat load calculations are how it should be done no doubt about it.

THIS IS NOT FROM PIPEFITTER636

[classical]

that's a crock!



,

You know nothing of pauls house so his statement could very well be true; in fact I belevie he has stated in the past he lives in an Igloo of sorts.

That is why you perform load calcs because there are so many types of building construction now that no rule of thumb will work.

I just did a house here in Houston 2-story 2800 sq.ft. that had a total load of 18,800 BTU's 11,500 of which was latent and the remainder was sensible and only had 3,300 BTU heat load.

[HeyBob]

THIS IS NOT FROM PIPEFITTER636

LOL............I know that, I saw that and started checking IP addresses etc looking for a dual rule breaking registration, so far I found nothing!

Anyway, welcome to H-Talk...........there is a ton of you 636 guys here, my best beer drinking buddy belongs to 636, does refer service.

You need to apply for pro membership, learn the secret handshake and get into the pro forums. Link is in my sig line!

[HeyBob]

Robert just for kicks say there are no such thing as load calcs, what size does you hvac sense tell you?

100 ton centrifugal, big tube boiler, Lot's of pipe, pumps and VAV boxes all over the place. We are gonna reuse the leaky 1970 pneumatic system though!

I'm gonna have Pipefitter636 help me install it, just sold the job yesterday!

[pipefitter636]

LOL............I know that, I saw that and started checking IP addresses etc looking for a dual rule breaking registration, so far I found nothing!

Anyway, welcome to H-Talk...........there is a ton of you 636 guys here, my best beer drinking buddy belongs to 636, does refer service.

You need to apply for pro membership, learn the secret handshake and get into the pro forums. Link is in my sig line!

I sent an E-mail earlier this week but didn't get a responce yet. Do you want me to resend it?

[hvaclover]

100 ton centrifugal, big tube boiler, Lot's of pipe, pumps and VAV boxes all over the place. We are gonna reuse the leaky 1970 pneumatic system though!

I'm gonna have Pipefitter636 help me install it, just sold the job yesterday!

Better throw in an ice rink to dump the exta capacity.

While you at it you can make a monsterous green house and grow tropical plants with the excess heat.