Any HVAC experts on here ?

[jumpwally 0]

Need to replace a 1960's era HVAC sytem for the inlaws. Planning on going Hi-Eff , the bids are all over the place as far as size, BTU's... every one seems to have a diff opinion on whats best.......
1800 square feet single story brick house, full unfinished basemnt under the whole thing..........

Any idea's ? Thanks to all

smile, be nice, enjoy life
FB # - 1083

[councilman24 37]

N expert but probably not enough info for size. Like where are you? Insulation?

I replaced one several years ago. Calculated pay back at time on high eff vs 93 (or whatever still needed chimney) was 30-40 years. Smaller house in MI. YMMV but make sure the savings is worth the cost differential. Energy costs, usage, etc goes into thinking. Of course energy eff. may be worth the cost for non financial reasons and prices may have changed.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[JerryBaumchen 1,260]

Hi wally,

Just off the top of my head, a 3-ton unit.

Many years ago I attended a seminar on least cost concepts. One guy out of Seattle had done a great study. His study said to get the smallest unit possible, run it like crazy & just replace when it gives up. That = the least overall costs for heat pumps.

I just could never get my mind to get to that point.

I live in a 1-story house, no basement, 2000 sq ft & have a 3-ton unit; I'm in Oregon which is just about the best place in the entire USA to use an air-to-air heat pump for both heating & cooling. If I were 20 yrs younger I would seriously consider a ground source heat pump; I consider them to be the most efficient.

And I'm a Carrier man; I consider them the best & would not use any other.

YMMV,

Jerry Baumchen
Ret'd Mech Engr

[BillyVance 34]

Billeisele on here is a HVAC expert. I'm sure he'll chime in when he has a chance to. He helped me with my HVAC issue when I had a 2 ton unit that was worn out but insufficient for my house, which had a 900 s.f. addition. So I got a 3 ton unit. MUCH better air flow

"Mediocre people don't like high achievers, and high achievers don't like mediocre people." - SIX TIME National Champion coach Nick Saban

[billeisele 130]

Woo Hoo - if I was smart I'd write this answer somewhere and save it, then just copy paste

it depends: where you live, which way the house faces(N-S-E-W), how much glass, which sides the glass is on, how much air in-leakage you have, how many people are in the house, what condition is the duct work in, is it hard pipe or flex, will it be replaced

there are so many dealers that just don't have a clue how to do it correctly, extra tonnage is bad unless you like higher bills and cold humid air

it's best to have a properly sized unit, on the hot days it should run almost all the time, you will hear people say that it works to "hard", that is BS, it's either on or off, it doesn't know anything about working hard

ask the dealer to run a Manual J calculation and review the assumptions and results with you, if they don't know what that is or won't do it then find another dealer

get something in the 14-16 SEER range, consider a 2-speed unit, it depends on what brand you get as to what options are available

your local power company may have rebates and experts that will help you with these questions

Give one city to the thugs so they can all live together. I vote for Chicago where they have strict gun laws.

[jumpwally 0]

Thanks much,,it's in the Chicago burbs, it's a 50's style all brick ranch with 1 large picture window facing east and all the rest of the windows are small. Insulation would be whatever was done in the 50's. The attic has been re insulated 2 years ago with blown in product. 3 people in the house,,it's my in-laws place. thanks again

smile, be nice, enjoy life
FB # - 1083

[akarunway 1]

http://www.ualocal364.com/

I hold it true, whate'er befall;
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[billvon 2,720]

>get something in the 14-16 SEER range, consider a 2-speed unit, it depends on what
>brand you get as to what options are available

Hey Bill, what do you think of the inverter drive units? A neighbor just got one and it's incredibly quiet (and so far pretty efficient) but I haven't heard anything about reliability or potential installation problems. (I know the proprietary thermostats are a pain in the butt.)

[shotandahalf 0]

Don't up size because you think it will cool better. It will short cycle and not dehumidify very well. It needs to be properly sized using a manual J chart. It takes into consideration heat load by using Sq. feet, insulation, size of windows and other variables. Depending on where you live a dual fuel system may be a good idea. It has a heat pump with a gas furnace instead of an electric air handler. JMO don't rush do some research.

[gowlerk 2,095]

Professionals probably hate this, but....

http://www.loadcalc.net/

Always remember the brave children who died defending your right to bear arms. Freedom is not free.