I have an existing HVAC system/No $$$ for upgrades

I was beginning to thumb through Rod's book trying to understand more about HVAC when a thought occured to me... Before I get to this, I apologize if the info is stated in that section. I wanted to get this post on here because as I've "skimmed through" the HVAC before, I've never seen anything about my question in general. From most of what I've read, all of the info is excellent for putting together a HVAC system to make sure you have the conditioning you need. However there are those of us that: 1.) Have systems where we simply cannot make any changes due to the system already being installed 2.) Can only do minor or major upgrades/changes 3.) Would like to make changes, but simply can't afford to/don't want to. What I'm wondering is this: Other than: installing a new air handler, main supply trunks, or dehumidifiers at the air handler, what are the most important factors we need to consider? Let's say we can't do anything about the efficiency of our HVAC system. Aren't we simply at bay of making sure that we have enough supply/return in the room(s) and make sure those supply and returns are balanced? Isn't that pretty much all we can do? In my particular case I was sitting here thinking of all the things I need to consider (sensible cooling loads/latent cooling loads) for my conditioning needs for my studio. I have a system I know I can't replace, my main trunk is in, and the only change I can make is to increase my duct size from my supply trunk, and add more supplies/returns. There may be a few "small" things here and there I can do, but these are the major things. For those who have basements that have an existing HVAC system and have access to ducts etc, changes/routings/additions etc can be made, but knowing those priorities are important. If your system simply can't supply enough cooling based on it's configuration, it simply can't do it, so in situations like this, what's the best we can do? Thanx!

Stan, The best you can do in that case - if it's a dedicated system for the basement - would be to maximize your flow - and live with a fan when it gets unbearable. If (on the other hand) it's a whole house system - then you need to be very VERY carefull that you don't steal so much from the system that remainder of the house suffers. I have seen medium size control rooms - say 450 s.f. that require 3 tons of cooling - and have been able to handle 1,000 s.f. homes wth 2 tons....... SO if I have a thousand s.f. home - and 2 tons of cooling - then I best not steal anything for my control room.......... Sincerely, Rod

I have a 3 ton system in my 1,976 square foot house. (It might actually be 3 1/2 or 4, now that I think about it.) (Man, I wish it were a split system... At night I'm cooling the entire house when I only care about one room for the most part. :x) I'm really glad I decided on the mini split. Leaving the house system alone makes the situation so much simpler for me. --Keith :mrgreen:

Ok, here's what I've gathered so far on my particular set up... 1.) I've learned that my HVAC Air Handler is a 2 ton/2 speed unit. I have a 10 seer Heat pump that goes with it. This HVAC system is dedicated only to my BASEMENT. 2.) My studio is in my finished basement. I have not had my HVAC system on for my basement all summer. The highest temp in my basement I've seen was 74 degrees and that was when the temp was 93 degrees outside. It was like this last year also. I never had to turn the unit on most all summer. For the most part, my HVAC system for my basement is fairly "non-existant" in the summer-warmer weather. Because of this, I would think I could focus on my Studio using my HVAC system during that time of year by closing off or somewhat closing off the vents in the other rooms of my basement. The only other reasons I would see in not doing this would be for mold-mildew reasons or strains on my Air Handler. If this is the case, wouldn't I need to at least keep the Air Handler fan on constantly for the WHOLE basement? If the optimum Relative Humidity should be 35%-45% to kill mold, wouldn't you have to have some type of constant ventilation to achieve this? Right now with NO HVAC my little "cheapo" humidity guage reads at about 60% fairly constantly. 3.) From my personal experience with a Heat Pump system, the air has a "cool" feel to it even when it's blowing WARM air. The homes I've lived in had gas heat which is a much warmer heat. Since my present home has a Heat Pump, I DO NOT want that air blowing near me from a Supply register/grill. Since 99% of my time I will be in the Control Room, having that coolish-warm air on my neck or over my head will simply be TOO uncomfortable. With that being said, because of water or drainage line PVC pipes in other ceiling cavities, and because it's recommended on this site you NOT have air blowing across your speakers I only have 2 ceiling cavities to put my Supply air duct/vent in. One of the 2 cavities will be too close to me, so I now definately have 1 ceiling-cavity position to put my Supply at. (Done deal! :wink: ) 4.) I will be having an ERV (Energy Recovery Ventilator) tied into my existing Air Handler for my basement. Without getting into a lot, I can tell you that in the winter, the "outisde air" (C-C-Cold air!) this unit brings in will be "somewhat" warmed by the ERV unit. This will add into the factor of "coolish-warm" air coming out of my vents in the winter. This is even MORE of a reason to keep those vents further away. From seeing this type of info, I've decided to install baseboard heaters in the Control room and Vocal Booth. I may not need them, (seeing the amount of heat my equipment and people inside the studio will generate) but I'll have additional heat in those rooms "just in case". 5.) Rod gave me his observation here... http://www.johnlsayers.com/phpBB2/viewt ... ght=#59658 So, I went ahead and added an extra Return vent between my mixing console and my rack to hopefully capture some of the heat these items will produce. I still have one 8" supply in the room that will have a vent to only blow the supply air forward. From my reading on here, I thought the rooms were suppose to have a slight amount of "positive" air pressure. Wouldn't having 2 return vents and 1 Supply vent negate this? (BTW, in one of the diagrams below there is the suggestion of having 2 returns and 2 supplies) That leads me to... 6.) Rod, this is for you... The total size of my Control Room should be about 228sf by the time it's finished. My Vocal Booth will be in the neighborhood of 91sf by the time it's finished. Seeing that putting in a larger supply duct from my trunk would make things worse, I guess staying with my 8" supply is what I'll have to do. (One last time, because I know you gotta' be getting tired of this...) A.) Do I stay with the one 8" supply VENT/REGISTER or put in an ADDITIONAL VENT/REGISTER of the same or different size in my Control room? (BTW...for my Control room, if I do put in another vent/register, the 8" DUCT will be supplying air for both vents/registers. The 8" duct will be in the same ceiling cavity with one vent mounted on the ceiling near one wall and the other vent mounted on the ceiling near the other wall...see diagram below) B.) To make things more "balanced", do I need to make the Supply in the Vocal Booth a 7" Supply (Instead of the present 8" Supply) since the Return is 7" and I can't change that? C.) Since my Supply location is set, do you have any suggestions for better locations of my Returns in my Control Room? I do have the capability to move them from where I presently have them designed. 7.) I tried this little experiment: My main Return for my Air Handler is a vent about 18" x 10" that's near the side-bottom of my Air Handler. When I close off or SEMI-BLOCK that return entrance, my Returns in my Control room & Vocal Booth have more "pull". Would putting some type of damper on this entrance aid in me balancing out how much Return I can get from those 2 rooms if I needed to increase the amount of Return air?? Would this have an effect on "burnin' up my Air Handler" prematurely? Ok... Now I figure once I can get some info on these questions I'm done with my HVAC. Then I can go celebrate at Cracker Barrel Restaurant and get me a Country-Boy Breakfast... Thanx guys...

I'm gonna take Rod's advice about maximizing my airflow. Got ANOTHER HVAC guy coming on Thursday. I plan to show him Rod's comments and see what he suggest as far as "maximizing" my airflow yet still have balanced returns. I'll compare what he says to what's in "the" book. I need to find out the amount of Static pressure my system has. No need in contacting the original installers...(long story). From some of my reading I need to get someone with a Magnahelic gauge and Pitot tube to put in the duct work on the supply and exhaust sides of my HVAC system. Before that though, I'll give the Air Handler manufacturer a call. I will attempt to get some other info also from a HVAC site I went to a few times. What info I get from the HVAC guy, the HVAC web site, Rod's book, and other inquiries to other HVAC installers I'll post here. I feel like there are people on here who may want/need to know such questions as: 1.) What is the best location to put a return? 2.) Is there a minimum or recommended distance the return should be from the supply? 3.) Should I have an upper and lower return for seasonal temperature changes? (Rod already answered this...the answer is yes, it would be better to have a return more near to the ceiling AND more near the floor to capture cool and warm air depending on the season/temps) 4.) What type vents-registers-grills are better for Studio use and what company manufactures them? 5.) For noise reduction is it better to oversize the vent-register-grill? 6.) Where's the best location for a balancing damper: at the vent-register- grill of the room, or back at the Air Handler? 7.) What do I do (or have done) to measure the amount of Supply I'm recieving in a room AND the amount of Return I'm pulling from that room? (This is so I'll know my supply and Return air flow is balanced) 8.) Does the average room get better air-flow by having the Supply on the ceiling or on the wall? Some of these questions may already be answered in Rod's book. If it is, I'll get to it this weekend for sure. If not, I'll find out, (or attemp to find out) the answers to these questions. If ya'll think of any more write it in a reply here. Thanx!