Heat Pumps and Electric Heating - Geothermal System for New Construction
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mcremens
10-05-06, 02:59 PM
Hello, n00b to the board here.
Construction will soon be started on my new home, and I plan on putting in a geothermal system. I've received 3 bids so far, two quoting a 4 ton system and the other a 5 ton system, and I am wondering how to decide on the size of system to go with.
I've scrolled through some other threads and seen remarks that cacluating the proper tonnage is very dependenent on the size and location of the home. That said, I have a few questions, if anyone might be able to help.
1) Are there any online cacluators out there that could help to give an estimate of the size system needed through inputs like indoor cubic footage, roof and window square footage, etc?
2) I did not receive any heat loss, AC load, or other analysis for the home with the bids. Do contractors typically do this and provide it to a customer at the initial bidding stage?
3) We may do 4 zones in the house 1) master suite, 2) kid's bedrooms (opposite side of house from master), 3) main level living spaces, and 4) basement. Any idea what the addition of these extra zones should cost? One bid said over $4000 extra for 4 zones.
4) Anything else I should be aware of when selecting a contractor.
Sorry for the length, but TIA for the help.
Construction will soon be started on my new home, and I plan on putting in a geothermal system. I've received 3 bids so far, two quoting a 4 ton system and the other a 5 ton system, and I am wondering how to decide on the size of system to go with.
I've scrolled through some other threads and seen remarks that cacluating the proper tonnage is very dependenent on the size and location of the home. That said, I have a few questions, if anyone might be able to help.
1) Are there any online cacluators out there that could help to give an estimate of the size system needed through inputs like indoor cubic footage, roof and window square footage, etc?
2) I did not receive any heat loss, AC load, or other analysis for the home with the bids. Do contractors typically do this and provide it to a customer at the initial bidding stage?
3) We may do 4 zones in the house 1) master suite, 2) kid's bedrooms (opposite side of house from master), 3) main level living spaces, and 4) basement. Any idea what the addition of these extra zones should cost? One bid said over $4000 extra for 4 zones.
4) Anything else I should be aware of when selecting a contractor.
Sorry for the length, but TIA for the help.
Ed Imeduc
10-05-06, 03:58 PM
#1 There is one here on line I dont have the www. for it cost is $50 . Might look a slant/fin its hot water but can do a heat loss only.
#2 If they are any kind of hvac company they should run a heat loss and AC load on the home.
That have to to know what to put in
#3 I do not put or like zone controls in a home. It is just not worth it. We just put more units in .Now say that one zone comes on so the 5 ton unit turns on with the 5 ton blower Now we have to have a by pass in the duct to get some of that air to come back to the blower so next the coil will freeze up now no air can get out so it cant cool the zone and will keep running. If the duct work is done right the 4 or 5 ton can keep the home to what you want.
Make sure that they put dampers in the ducts. That way you can kind of make it work the way you want
Might look around there see if you can get a DX geo set up it dont work on water in the lines and a water pump running most of the time, The DX Geo put the freon lines in the ground.
ED ;) my .02 cents
#2 If they are any kind of hvac company they should run a heat loss and AC load on the home.
That have to to know what to put in
#3 I do not put or like zone controls in a home. It is just not worth it. We just put more units in .Now say that one zone comes on so the 5 ton unit turns on with the 5 ton blower Now we have to have a by pass in the duct to get some of that air to come back to the blower so next the coil will freeze up now no air can get out so it cant cool the zone and will keep running. If the duct work is done right the 4 or 5 ton can keep the home to what you want.
Make sure that they put dampers in the ducts. That way you can kind of make it work the way you want
Might look around there see if you can get a DX geo set up it dont work on water in the lines and a water pump running most of the time, The DX Geo put the freon lines in the ground.
ED ;) my .02 cents
mcremens
10-05-06, 04:22 PM
Thanks for the reply.
a couple of further questions.
On 2) - Is this something that contractors will typically provide for a potential customer to review? Is it off-putting to aske a contractor to this before we've selected one to do our work?
on 3) - I see that there can be issues with zone controls, but can they helpsave money in the long run by regulating temperature during the day in zones? For instance, during the day there's no reason to heat / cool the bedrooms as everyone is in the living areas, and the opposite is true at night. Will putting in an oversize unit or multiple unit end up costing more in energy consumption as the entire house will be heated or cooled to the same temperature? Or is the savings justifiable because of maintenance issues (coils freezing)?
Looks like I also need to educate myself on using dampers to control room temperatures instead of zones.
a couple of further questions.
On 2) - Is this something that contractors will typically provide for a potential customer to review? Is it off-putting to aske a contractor to this before we've selected one to do our work?
on 3) - I see that there can be issues with zone controls, but can they helpsave money in the long run by regulating temperature during the day in zones? For instance, during the day there's no reason to heat / cool the bedrooms as everyone is in the living areas, and the opposite is true at night. Will putting in an oversize unit or multiple unit end up costing more in energy consumption as the entire house will be heated or cooled to the same temperature? Or is the savings justifiable because of maintenance issues (coils freezing)?
Looks like I also need to educate myself on using dampers to control room temperatures instead of zones.
Ed Imeduc
10-05-06, 04:36 PM
#2 any HVAC company that wants a job and knows what they are doing will give you a heat loss and AC load on the home . Hey just tell them you want to see it.
#3 As we have so many rocks we dont use any GEO here at all. it all air to air heatpumps.Now most of the home are large say from 3000 sq to some up to 9000sq ft Like on a 3 K to 4K home might go with 3 units. Now like you say thats how to save on just what gets the cool or the heat and you dont have a 5ton unit going on and off.
If you want to look at it another way that works real good. Say 4 ton in a home one duct line we put a split coil in the unit 2 2 ton coils. with 2 2 ton compressors and a 2 stage tstat. works like a dream .
Like on dampers some times we put the heat pipe for the lower level or basement down in the slab. that way one damper will put more heat down there or more cool for upstairs.
Ed;) thats my .04 cents now
#3 As we have so many rocks we dont use any GEO here at all. it all air to air heatpumps.Now most of the home are large say from 3000 sq to some up to 9000sq ft Like on a 3 K to 4K home might go with 3 units. Now like you say thats how to save on just what gets the cool or the heat and you dont have a 5ton unit going on and off.
If you want to look at it another way that works real good. Say 4 ton in a home one duct line we put a split coil in the unit 2 2 ton coils. with 2 2 ton compressors and a 2 stage tstat. works like a dream .
Like on dampers some times we put the heat pipe for the lower level or basement down in the slab. that way one damper will put more heat down there or more cool for upstairs.
Ed;) thats my .04 cents now
schulze31
10-08-06, 07:16 AM
im sorry i would have to dissagree i put zones in plenty of houses with no problems at all. if desighned properly. also with all it sounds like your willing to do i would assume you get a variable speed unit.? with that said i would try and keep the zones together right off the plenum if possible. and i would agree with ed on the fact that if you are on different levels of the house and you could help it, it wouldnt be a bad idea to just put a additional smaller unit.