Hvac guys step inside....

[skeeterj01]

I had what I thought was a reputable guy install a new unit 3 years ago. I asked what size unit I needed and he said 2.5 ton. I told him I planned on building another bathroom on and he said 2.5 will be plenty. Well now that the bathroom is built on the house doesn’t cool well. I’ll have thermostat set on 70 and it’ll be 74. Now this is dead heat of summer which I can deal with but I still don’t like not being in control of being able to set it where I want. As stated the unit is 3 years old and I would hate to have to pony up and get a bigger unit. It’s mainly the bathroom( new added on) and master bed room that isn’t cooled well. Anyone have any suggestions? I’ve thought of a nice digital window unit. I wouldn’t put it into window I would frame it into the back part of house so you couldn’t see it. Thought about the stand up ductless as well. Looking at all options.

[brushsjigs]

Was an air return added in the bathroom, or just piped a supply in the bathroom.
IM not a havoc guy, but you cant pipe it in with out taking it out. How far from the room is the existing return.

[skeeterj01]

Was an air return added in the bathroom, or just piped a supply in the bathroom.
IM not a havoc guy, but you cant pipe it in with out taking it out. How far from the room is the existing return.

Just piped new duct in.

[lakefolk]

what is the total sq ft of the space of the house being cooled including the new bathroom?
did it cool good before the new bathroom?
what is the difference in the temp of the air coming from the vent compared to the outside air temp?
are these rooms at the end of a long run of the ductwork?
how big is the bathroom?
have you checked the new duct work? or all the duct work for that matter?
you might need to get a balometer and adjust some vents to direct air to those rooms.
could be lots of stuff.............

[lakefolk]

Was an air return added in the bathroom, or just piped a supply in the bathroom.
IM not a havoc guy, but you cant pipe it in with out taking it out. How far from the room is the existing return.

every room does not require a return........

[brushsjigs]

every room does not require a return........

Correct, but was asking how far the room is from the existing return. If its a large room that he added and its far from the existing, his air is not circulating properly.
Ive seen it happen on commercial sites where the architect did not call for a return and the room was always hot or cold, and a standard balance would not correct it. They had to install an additional return from that room.

[skeeterj01]

what is the total sq ft of the space of the house being cooled including the new bathroom?
did it cool good before the new bathroom?
what is the difference in the temp of the air coming from the vent compared to the outside air temp?
are these rooms at the end of a long run of the ductwork?
how big is the bathroom?
have you checked the new duct work? or all the duct work for that matter?
you might need to get a balometer and adjust some vents to direct air to those rooms.
could be lots of stuff.............

House is approx 1400 sq ft
it would keep it at a steady 70 degrees
yes the bathroom and bedroom has long run of duct
bathroom is a 14x24
ductwork is intact and doesn’t seem to be leaking anywhere I’ve looked

[motomania]

Im not an hvac guy; but our new house upstairs always was a bit warm. I visually checked the ceiling insulation; it looked fine. But, then used a FLIR thermal imaging camera I got for my iPhone (for another reason), Boy was I wrong. Lots of spots of thin blown in cellulose insulation, that looked deceptively thick when looking at it. So I went to Home Depot and bought quite a few of the bricks of the blown cellulose, just sliced them open and scattered them on the thin spots........problem solved. Just something to think about.

[nowakezone]

Put in a mini split system,they're affordable and work great

[skeeterj01]

Put in a mini split system,they're affordable and work great

care to elaborate

[Bassman Ia.]

Our house had a cold return duct in the bathroom. There was a standup linen cabinet over the top of it with a real small register built into the toe hold. When we re-did the bathroom we sat a new custom built cabinet over it. One problem with a cold air register in a bathroom is it will draw moisture straight into your furnace. When I installed the new doors, I kept the bathroom door up off the floor 1 inch, it also helps the exhaust fan remove the moisture when showering.

[Axkiker]

Im not an hvac guy; but our new house upstairs always was a bit warm. I visually checked the ceiling insulation; it looked fine. But, then used a FLIR thermal imaging camera I got for my iPhone (for another reason), Boy was I wrong. Lots of spots of thin blown in cellulose insulation, that looked deceptively thick when looking at it. So I went to Home Depot and bought quite a few of the bricks of the blown cellulose, just sliced them open and scattered them on the thin spots........problem solved. Just something to think about.

Ive thought about getting one of those as I don't think my insulation is good.. Was it very expensive?

Speaking of AC units mine has basically been running non stop. Thinking I need to add more in the attic. Used one of those laser temp gauge things and at the exchange its running around 75 or so and out of the vent 55 or lower depending on how long you stand there or how close you get to the vent. So I think the unit is working appropriately as ive always heard you can retain a 20 degree difference.

[grout-scout]

Close down the other vents and force more cold air to the bathroom.

[lakefolk]

House is approx 1400 sq ft
it would keep it at a steady 70 degrees
yes the bathroom and bedroom has long run of duct
bathroom is a 14x24
ductwork is intact and doesn’t seem to be leaking anywhere I’ve looked

how did you duct the new room? did you increase the duct size of that main run to allow for the increased area? did you rob/split a duct that already serviced the bedroom or run a new service point from a plenum?
although not an optimal solution you might could get away with installing an inline duct booster fan. 2-1/2 ton would usually service 1400 SF unless you have high or vaulted ceilings and the cu ft is higher than the average 1400 sf house.. the first thing i would do is get that air temp leaving the vents and check the air volume compared to other rooms in the house.
I am really suspecting a duct work issue..

[DvKing]

That is a dang nice bathroom!!!!

[572 Fitter]

Was an air return added in the bathroom, or just piped a supply in the bathroom.
IM not a havoc guy, but you cant pipe it in with out taking it out. How far from the room is the existing return.

Who puts a return in the chit room????

[skeeterj01]

how did you duct the new room? did you increase the duct size of that main run to allow for the increased area? did you rob/split a duct that already serviced the bedroom or run a new service point from a plenum?
although not an optimal solution you might could get away with installing an inline duct booster fan. 2-1/2 ton would usually service 1400 SF unless you have high or vaulted ceilings and the cu ft is higher than the average 1400 sf house.. the first thing i would do is get that air temp leaving the vents and check the air volume compared to other rooms in the house.
I am really suspecting a duct work issue..

branched off the existing bedroom duct work

[Chadsc]

branched off the existing bedroom duct work

There's a lot of your problem most likely. I don't care how many runs you pull off, if a trunk is sized for X amt of CFM's it's not going to matter. Unfortunately either way at minimum your looking at some reconfiguring of duct design. 2.5 tons in my opinion should do that space unless you have a crap ton of windows or something. I'm doing my 1800 sq ft. House with a 2.5t but I'm not expecting mine to get down to 70 either. As long as I can maintain 74/75 on a 90+ degree day I'm happy.

Technically ACCA states that 74 Indoor dry bulb +/- 2* is considered normal target range for load calcs. So if you want to run 70* 24/7 you technically need to oversize your unit.

[nowakezone]

Mini split is a ductless unit, it comes with a remote control. You hang the unit on the wall and the small compressor goes outside. You can get a 1/2 ton up to a 2ton unit. I have a 2 ton unit in my game room. It's 900 sf and it cools and heats it great. Google mr. Slim by mitsubishi.
Lots of companies make them

[BroWhoop]

2.5 ton is marginal for the sq. ft. depending on a lot of different things. The 1st thing to do is have the a/c serviced. There are a lot of refrigerant leaks today. And you never install return air in a bathroom. You have exhaust but no return. There are host of potential problems. Capacity, duct and mechanical issues. Start with he simple checks 1st.