Ready to start construction...1st up to bat; HVAC

Hey everybody! I wrote some time ago with HVAC concerns that I graciously got good response from. We are finally ready to finish the basement alltogether, and I want to make sure each step of my studio is correct. So, let me get to the point... We live in a new house that's 3 years old. Each floor has it's own heat pump and air handler. We decided (with Blessings from GOD) to add a Heat Pump/Air Handler specifically for the basement. I got 3 HVAC people to come over to give me an estimate and their professional input. Well, as ya'll said, pretty much NONE of them had a lot of info on constructing for a recording studio. As I was told in one of the responses I got from my last post; "stick to your guns" which I have, even when the HVAC guy tried to make me feel like I didn't know what I was talking about. Anyway, these are the things I told him I wanted: 1.) to have seperate send and return lines from the blower and air return units to my control room and live room 2.) The duct to be rigid & lined (fiberglass?) for quiet air flow with at least two 90 degree turns/bends 3.) For the ducts to be slightly larger than the normal size ducts installed in the basement to slow down the air velocity 4.) To have some type of filter prior to the air reaching the wall/ceiling grill, and 5.) To have some type of grill slightly larger than regular size grills that will blow air quietly and with less velocity. He pretty much said he could do all the things I asked, but there is something...something that tells me I better check and make sure I'm getting what I requested. What I need to know is: 1.) Did I miss anything to have for my HVAC (studio) system? 2.) Do you know of any info or concerns I should have concerning mold? and 3.) Do I need an air return in my door air locks. (I plan to have two- 2 door air locks... 1 set of doors to enter the control room, and the other set to enter the live room) There will be approximately 1 foot air space between the 2 doors in each location. (Should I have more air space?) As of right now, no framing has been done. I plan to do that after the HVAC work is done. That's pretty much it. Any info/responses will be greatly appreciated Stan

Hey Stan, Looks pretty good, except two things:

• Where's your ventilation? Ventilation = fresh air from outside. You're probably going to need that to pass code. Conditioning the air is one thing (for comfort), but a supply of fresh air is a requirement, since you're probably not going to have any operable windows to give you the oxygen you need for living.
• Have you considered silencers? They're like big boxes that act as ducts closest to the registers. These may be necessary to preserve your TL to the outside world for your ventilation that I'm thinking you don't have yet. ;-)

Take a look at my project thread, starting at page 18, where you will follow my rollercoaster ride of trying to come up with a ventilation solution. It does have a happy ending -- at least, so far! :roll: Hope that helps... --Keith :mrgreen: P.S.: I'd have offered this advice to you "way back when" if I'd have known then all that I know now! :lol:

The super fast responses! Hey Keith, Thanks for the comments. I'm somewhat confused tho'. From my understanding of how my HVAC works, the air is recirculated coming from the rooms with returns and the main return register in the hallway. The air is sent from the return unit back to the heat pump. Is this not considered "fresh air"? I would think somewhere within the heat pump fresh air is drawn in from it. If this is incorrect please let me know. The HVAC guy is coming to install the basement unit this week or early next week. Thanx!

I didn't mention that this and all rooms in the basement will have air "send" ventilation. (Ahhh...the cold or warm air blowing in!)

I've become somewhat well-versed in this lately, and I had some of the same misconceptions as you at first... (Have you read through my thread starting at page 18 yet? ;-) ) In short, no, all the "blowing" going on at the heat pump (outdoor unit) is to allow the unit itself to breathe. The air being "returned" from the room/house is flowing back to the air handler, which heats (or cools) the air by blowing it over coils to change its temperature, then the same air is sent back to the room/house. Think of it this way -- the heat pump (or A/C) is for comfort (or, in some parts of the country, survival ;) ). But windows are for ventilation (and emergency exits) and natural light. If your room doesn't have a window, and it has "conditioned air," it's considered "habitable," and "habitable" needs a window, or mechanical ventilation, in order to be legal. The "natural light" requirements that are called for in building codes are usually easier to get around than the ventilation requirements. At least they allow for mechanical ventilation -- otherwise you'd have to have an operable window in your studio space -- think of what that would do to your iso! :shock: Page 18+ -- check it out... And if you're in a huge hurry, then skip to Sun Aug 14, 2005 on page 20. --Keith :mrgreen: P.S.: It's entirely possible that I'm "way off base" in my assessment of your situation... HVAC is certainly not the same everywhere and I'm certainly no expert. All I really know is what I had to do to my own plans in order to get them approved for a building permit (which, thankfully, I got this week! 8) ).

also something about making sure your unit is undersized for the space so that the extremely good insulation won't cause it to short cycle... studios need smaller ac's than regular rooms because of the insulation or does that apply to heat pumps? anyway you might want to check into that. :)

Yes -- what Dan said... Follow this link.

Hey, thanks Keith and Dan for the info! Keith, I checked out the thread(?) from the link you told me to check out (page 18+). I was reading the responses until my head hit the table and woke me up. Got red eyes from all that reading. I've had 2 HVAC guys come in today. (Called em' this morning) I called 7 of em' in all. From what I was told, in this county, there is no code that says outside air has to be incorporated with inside or recirculating air for basement construction. I've asked 2 (of the 7 I called) and they both said the same thing. HOWEVER, I got a descent estimate to install a heat pump and air handler unit that WILL incorporate outside air. The guy did say that if it stinks ouside, you'll be welcoming the smell inside! I've got about 1100 square feet in my basement (only a PART of that 1100 sq ft is my studio!) and I've decided on a 1.5 ton heat pump unit. I noticed Dan was saying to make sure the unit was undersized. Well, as a rule of thumb I was told to figure to have 1 ton per every 500 square feet. If this is correct, this unit should fit in the "undersized" category. I also read Rod's comments about oversizing the return ducts which I plan to do. I'm also looking into the silencer that was suggested, although I noticed there were other options to consider. (I can feel more red eyes coming...) For mold, the HVAC guy said they could install an ultra-violet light inside the air send and return lines. This is suppose to kill mold and other airborn critters. I'm not sure I can afford that but we'll see. I also read about a "variable speed" air handler unit on one of the forum post here which is suppose to be quiet starting and running. One of the HVAC guys mentioned that also. One of the units I was told about is suppose to greatly assist with dehumidification by automatically adjusting the fan speed. (Just something to pass along to possibly help someone else) Hey, I even got one of the HVAC guys that told me how to figure how much heat my equipment would generate with a formula. He said to take the wattage used on each unit I had to be plugged up, add the wattage of all the units together for a total, then multiply it by 3.14. The number you come up with is the number of BTU's of heat the equipment generates. (If you hear from Rod run this by him to see if I was told right) Anyway, if ya'll think of ANYTHING else I need to consider, HOLLER at me cause I'm suppose to have the unit installed in approximately 1 to 1&1/2 weeks then immidiately begin framing. Oh yea, I'll be buggin' ya'll about the framing too after I search around on here a little more. 1 more thing...Does this site ever have a convention or anything for all the people that are into this stuff? Man-O-Man...you could count me in on that! Stan

I still need to know about running an air return in my door air locks. Is that necessary? I'll have approximately 1 foot of air space between the two doors. Thanx!

camistan wrote:

I still need to know about running an air return in my door air locks. Is that necessary? I'll have approximately 1 foot of air space between the two doors. Thanx!

If no one is staying in there, no. Andre

camistan wrote:

From what I was told, in this county, there is no code that says outside air has to be incorporated with inside or recirculating air for basement construction. I've asked 2 (of the 7 I called) and they both said the same thing.

I don't know if I believe them. :? Granted, I live in California, and my city has adopted California Building Code (CBC) as its model codes... And yes, they're stricter in some ways compared to other parts of the country. However, CBC is derived mostly from UBC (Universal Building Code). The code basically says that ventilation (mechanical or via window) may not be needed in non-habitable spaces, such as closets, utility rooms, etc. But non-habitable spaces can't be "conditioned," which means you're not allowed to heat or cool them for comfort. Once you condition the space, it becomes classified as habitable... And once it's habitable, it needs ventilation. Bedrooms and basements are even more strict because there must be an operable window for emergency egress. I leave room for the possibility that it may be true that your municipality does not require ventilation in habitable spaces. However, asking the contractors themselves may not be your best bet for getting the correct answer that applies to your situation. Ideally you should be contacting your municipality's building department yourself to determine (1) what model building codes they have adopted (probably UBC -- if so, look up 1203.2 & 1203.3) and (2) what that code calls for. Again, I'm not the code expert around here... even though I sometimes feel like I'm the in a minority of those who give a rat about it... ;-) If you care (and I hope for your sake that you do -- you seem to!), you'll get the official answer and you'll be able to work around whatever constraints that code requires. --Keith :mrgreen:

whether or not it's legally required, you DO need air to breathe, right? :) i'm sure many people get away with this, but i don't think bad air is very conducive to creativity, even if you don't pass out and die ... :wink:

camistan wrote:

He said to take the wattage used on each unit I had to be plugged up, add the wattage of all the units together for a total, then multiply it by 3.14. The number you come up with is the number of BTU's of heat the equipment generates. (If you hear from Rod run this by him to see if I was told right)

I'm not much with geometry, but I think 3.14 is pi and you'd be figuring the diameter of something. I think BTU to watts measurements need be calculated by 3.412. And that gets you BTU/hr. Actually though, well after some research, here's how I'd do it. (Amps the gear pulls) x (voltage it runs at)=VoltAmps(VA) x (power factor of .8 since 1VA doesn't equal 1WA) = Watts Then you'd have to take Watts x 3.412 BTU/Hr-W = BTU/Hr. So if the gear pulled 10 Amps at 120V, it'd look like this 10A x 120V = 1200VA x 0.8 (pf) = 960W. 960W x 3.412 BTU/HR-W = 3275.52 BTU/HR. I think 1200 BTU/Hr is equal to 1 ton of cooling capacity, but that might be different depending upon insulation or something, so that's very up for discussion.

Hey Sword9, thanks for the info. I'll try it out just to see where I'm at with the unit I'm having installed. Also, I had my 3rd and 4th HVAC estimate done. Both of them also said bringing in outside air is not required here. One guy said if I had GAS heating it would be required. I guess different requirements for different areas. As I said though, I'm incorporating incoming air in my system anyway, so I'm laying the "incoming air as a requirement" thing to rest. I Will attempt to list a drawing of the deminsions of my control room and live room (vocal booth) in the next couple of days. I'd like to get input as to the best location for my air send/return registers. My head is about to fall off my shoulders because it's tired of all the reading and estimates, and checking this and that...so if you see a body walking around aimlessly with no head, do me a favor: take a piece of paper and write "Stan in Kentucky" on it; tape it on the back of the body, and turn the body in the direction of Kentucky and good ol' Stan. Later dudes

where in KY are you?

cami, i can send some pictures: I bought the doors pre-hung, but ended up cutting the bottom (the threshold) off. Aligning the bottom of the door to the finished floor was kinda a challenge, but it turned out ok. just make sure your framing is level first, then check the door jamb for level and plumb... make sure you also allow any clearance for the door to swing (i am kinda running into that problem, because the cement floor is a bit un-even. let me know what specifics you have, and i'll do my best to answer... k