[Shah Mat]

I'm putting a heat pump into a rental house and trying to save money I'm doing the ductwork myself. Had a guy tell me this is the way it should be done... Opinions?

Air Handler is a Trane 1 1/2 ton with 3 speed blower. Model # TWE024P13,PB,FB

 

[rgearhead]

Im not much help on duct sizing, 1 1/2ton seams small to me, what size unit was there before??

 

[sc4u2nv]

what sq footage is the place?

 

[rgearhead]

what sq footage is the place?

well with what he has posted , i come up with 776 sq' not as big as i first thought..

 

[Pamopar]

are you planning on a high & low return, with a heat pump you really should do it this way. Actually it would be better to have high/low returns in each individual room, your duct sizing is plenty big enough

 

[Topfun99]

Gee, what do the drawings that were signed by a Professional Engineer show?

What, no drawings? I hope everyone involved realizes that doing this work without permitted documents will get you fines and bad attitude from the building department. Yes, you may get away with it initially, but when they figure it out they will require a Professional Engineer to sign off on the work. That plus a few extra dollars for fines will cost someone in the future.

Just sayin.....

 

[rgearhead]

Gee, what do the drawings that were signed by a Professional Engineer show?

What, no drawings? I hope everyone involved realizes that doing this work without permitted documents will get you fines and bad attitude from the building department. Yes, you may get away with it initially, but when they figure it out they will require a Professional Engineer to sign off on the work. That plus a few extra dollars for fines will cost someone in the future.

Just sayin.....

Ahh, it's a Rental, what could happen ................

 

[iceman5426]

i would do 12x10 coming off of plenum and then reduce to 10x8 that way you only have to reduce on one side of the duct work. in the bathrooms i would only use a 8x4x5 boots with 5" flex. i would use 12x6x6 boots in the rest of the house. Make sure that the return is larger than 24w x 12h. If you have room use a 25x16 return grille. this will help keep the noise level down. Also i would use a 1 way curved style ceiling grille to help throw the air farther across the ceiling towards the exterior wall. Hope this helps.

 

[Pamopar]

don't know what happens where you are from but here in PA, HVAC work is about the least regulated thing (residential), its usually up to the contractor for duct layout/sizing etc.

 

[opaleski]

Looks good--Do it!!

Been in the business for over 35 years. Do what ever you can without letting the government know what you are doing. They control enough of our life and get enough of our taxes

 

[Topfun99]

don't know what happens where you are from but here in PA, HVAC work is about the least regulated thing (residential), its usually up to the contractor for duct layout/sizing etc.

I guarantee you the regulations are there - it's all about safety of the general public. It could well be that the contractor has signed/sealed drawings and is following them or he is doing what he thinks he can get away with. How much they enforce the regulations is always a local thing.

When something goes wrong, the liability will fall heavily on those that did not abide by the lawful regulations.

 

[Hitchcock]

Gee, what do the drawings that were signed by a Professional Engineer show?

What, no drawings? I hope everyone involved realizes that doing this work without permitted documents will get you fines and bad attitude from the building department. Yes, you may get away with it initially, but when they figure it out they will require a Professional Engineer to sign off on the work. That plus a few extra dollars for fines will cost someone in the future.

Just sayin.....

In this area we dont have to pull a permit or have a fucking engineer sign off on running ductwork. Much less a building permit.
Are the city codes really that thight where you live?


And to the OP, if you really want to use flex you can. But from expierence I hate it. No matter how well supported it is in a few years it will start collapsing and airflow will go with it.

 

[GRIM REAPER]

You don't have to worry about in Fredricksburg.Very laid back up there. I'm from the area. I agree just do it. If you do run into a problem i have a good friend in the business up there that could help you out

 

[Pamopar]

I guarantee you the regulations are there - it's all about safety of the general public. It could well be that the contractor has signed/sealed drawings and is following them or he is doing what he thinks he can get away with. How much they enforce the regulations is always a local thing.

When something goes wrong, the liability will fall heavily on those that did not abide by the lawful regulations.

no I am a contractor, even when the inspectors are out on the job they are never inspecting the HVAC

 

[ford man]

thats a 2ton unit by that model # and you should come off plenum with 12x8 both ways then reduce to 10x8

 

[ford man]

i live in fredericksburg shot me a pm and i'll come out and look at it for you.

 

[Topfun99]

In this area we dont have to pull a permit or have a fucking engineer sign off on running ductwork. Much less a building permit.
Are the city codes really that thight where you live?


And to the OP, if you really want to use flex you can. But from expierence I hate it. No matter how well supported it is in a few years it will start collapsing and airflow will go with it.

This is a new installation that apparently includes a new heat pump and air handler along with the ductwork. I don't know every regulation in every city/county/state in the country but typically every area has some form of regulation concerning new consruction. Do the electricians just show up and do whatever they want?

Again, someone will be responsible if something goes wrong. The OP should be aware that he is assuming liablity for his work that is way above what he may perceive. That liability will not go away because someone in the business "looked at it for him".

I would suggest instead of making light of my posts, that someone be specifc and state the applicable codes that he should be aware of in the locality he is working.

 

[quick1sr]

^^^^bravo, safety and responsibility come into play here...do the job correctly saves you money in the long run..think about that

 

[moneypit]

looks good just put dampers in the take offs so you can turn down the bathroom. and just do it with good workman ship and you want have any problems with code. on code around here (SC) you just have to have r-8 inso and dampers in branch lines. the air handler can be used with a 2 or 1.5 ton hp. the 1.5 match up is a lil more efficient. o allso put unit in a drain pan with a cut off switch.

 

[408-COUPE]

You have about 900CFM worth of ducting where the 1 and1/2 ton produces about 600CFM (typically is 400CFM per ton). I think you will be alright since the house is so small (assuming it doesnt have high ceilings and a lot of windows), I would put a 4" duct in the bathroom, but thats just me.