HVAC Help in HT - ductless mini split - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 22 Old 02-24-2020, 10:58 AM - Thread Starter
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HVAC Help in HT - ductless mini split

Trying to figure out how to heat my entire basement and the dedicated HT....will not be using the existing furnace, will leave that alone to condition the rest of the house.

I've been quoted a 2 ton, 2 zone mini split with a 1 ton head in the HT and a 1 ton head in the rest of the basement.

A 4 ton, 2 zone with 2 ton in HT and 2 ton in basement

And a 3 ton with 1 ton in the HT and 2 in the basement.

Talking with pros in HVAC forums they think any of the above is overkill.

Since my HT will be sealed off, soundproofed etc it will not really receive any heat/cool from the rest of the basement.

Looks like a mini split head in the dedicated HT is fairly common with this forum no? How are you finding it works out?
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post #2 of 22 Old 02-25-2020, 09:54 AM
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My build is still in progress and the mini split hasn't even been mounted yet so I can't tell you how well it works but I do want to point out the need for ventilation. The minisplit will heat and cool but over time the air will become stale in a sealed room. Do you have plans to bring in fresh air?
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Subscribed. I’m curious on how to get fresh air into a sealed theater as well.
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post #4 of 22 Old 02-25-2020, 10:09 AM - Thread Starter
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Originally Posted by weavinator View Post
My build is still in progress and the mini split hasn't even been mounted yet so I can't tell you how well it works but I do want to point out the need for ventilation. The minisplit will heat and cool but over time the air will become stale in a sealed room. Do you have plans to bring in fresh air?

No, had not thought about that. Doesn't it bring in any sort of air from outside through the lines to the outside unit? Or is it a totally sealed system..
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post #5 of 22 Old 02-25-2020, 10:32 AM
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I have two dead vents in my theater to exchange the air. One pulls air from the rec room by the patio door into the front soffit of the theater and another in the rear soffit that pulls air out of the theater and deposits it in the hallway. They are on when ever we are in the theater and work great. I am using ACinfinity T8 fans with controllers for this. I also have HVAC in the room again one supply in the front soffit and one return in the back. The dead vents let me recirculate the air even when the HVAC is not running.

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post #6 of 22 Old 02-25-2020, 10:58 AM
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No, had not thought about that. Doesn't it bring in any sort of air from outside through the lines to the outside unit? Or is it a totally sealed system..
Most likely your minisplit does not have any fresh air exchange. It simply recirculates air in the room.

I also am going to use AC Infinity fans to exchange air with the rest of the house. In fact I just received my T8 inline fan and I'm impressed with it.

As far as calculating your ventilation needs, opinions vary. I've seen 8-10 air changes per hour down to "7.5 CFM per occupant + 3 CFM per 100 sq.ft" (Nyal Mellor's recommendation).
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You can also use an ERV to bring in fresh air.

I will be doing some kind of air exchange in my new theater as well. It will be completely sealed so it will need some fresh air.
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The best, easiest, and cheapest solution by far in my opinion is to tie the theater to the basement HVAC using dead vents or silencers.
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post #9 of 22 Old 02-25-2020, 03:41 PM
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The best, easiest, and cheapest solution by far in my opinion is to tie the theater to the basement HVAC using dead vents or silencers.
Fair enough but if the HVAC isn't running you will still want a way to exchange the air. After 2 or 3 movies or if you fill up the room it will get stale pretty quick
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post #10 of 22 Old 02-25-2020, 03:51 PM
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Fair enough but if the HVAC isn't running you will still want a way to exchange the air. After 2 or 3 movies or if you fill up the room it will get stale pretty quick
You can set the HVAC to circulate air constantly.
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post #11 of 22 Old 02-25-2020, 04:07 PM
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You can also use an ERV to bring in fresh air.

I will be doing some kind of air exchange in my new theater as well. It will be completely sealed so it will need some fresh air.
Kudos to you for two things. First trying to learn more before buying a unit, secondly for not trying to cobble up the system for the rest of your house just to heat and cool your HT.

Not knowing how big your basement or HT is this. is mostly speculation, but a 2 ton might be too big, 3 ton absurd, 4 tons totally insane. In air conditioning bigger is not better, in fact it's the worst thing you can do. An AC will dehumidify but only while it's running. Oversized units cost more initially for the larger equipment, you will use more energy running larger motors, and they will likely short cycle (<20 min run times) which will not remove much humidity.

The only way to properly size a unit is by using ACCA Manual J. There are some sites on the web that you can use for free or low cost for 1 calculation, or you will probably have to pay a contractor to do one. If a contractor has the (expensive) software and knowledge to use it, he won't show his calculations until you sign a contract with him. This is to keep you from bid shopping another contractor that won't do the calculation. Basement loads are lower for heating and much lower for AC. There are about 20 or so factors that go into a manual J, sq footage, cubic footage, insulation above, below, and around the area, sq footage of exterior glass (doors and windows), your local climate information, area under ground / above ground, etc.

There are a number of really good minis on the market, and some are really cheap ones too. Midea, a Chinese company makes a lot of these units marketed under a lot of labels (including Carrier) and most of the ones you see in the DIY area of big box stores. Mitsubishi, LG, Fujitsu, and Panasonic all make really good units. They all offer variable speed units which I strongly recommend, they will adjust compressor and blower speeds to match the load.You can get units to support up to 4 indoor cassettes. They are very energy efficient partially because of the variable speed, and they use plastic fans as opposed to metal on traditional systems which require less torque and horsepower to run.

The folks that talked about fresh air intake are, I believe, on a good track. Mitsubishi, Fujitsu, and Panasonic I know of, maybe more have a fresh air option if you use a ceiling mount cassette. The ceiling mount cassette looks like one you would see in an RV only much quieter since the compressor will be remotely mounted, only the blower will be running which will be very quiet. The ceiling mounts are less obtrusive than wall mounts in my opinion. The controls on these units are very unique to the brand name, but if you can control the fresh air separate from their thermostat there are a couple of good options. Both Honeywell and Dwyer Instruments make a carbon dioxide control, make sure you get one that has relay outputs. The optimal range is between 400-700 PPM, the lower the better. One of these could be used to control a damper on the fresh air intake.

Something else you might want to look at is a dehumidifier. There are a number of central ducted units on the market that will be totally automatic. You can buy a very low cost temp/humidity meter from Amazon or Walmart and monitor for a while. One of the best times to test is coming pretty soon, what's called "shoulder season", typically in spring or fall depending on climate when your home needs little if any heating or cooling and rainy or humid outdoor conditions. The ideal indoor humidity range is between 45-55%. Correct humidity levels are comfortable and healthy. It helps prevent mold growth, dust mites, and damage to wood floors and furniture.

Home Theaters are likely to be the best air sealed and insulated areas of the home. Depending on the size of the room and number of occupants that might be there for an extended time will quickly increase both humidity and carbon dioxide levels by just exhaling their breath.

Again, kudos for doing your research. Keep researching what will work best for you before you purchase. It's an expensive but long term investment.
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post #12 of 22 Old 02-25-2020, 05:25 PM - Thread Starter
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Kudos to you for two things. First trying to learn more before buying a unit, secondly for not trying to cobble up the system for the rest of your house just to heat and cool your HT.



Not knowing how big your basement or HT is this. is mostly speculation, but a 2 ton might be too big, 3 ton absurd, 4 tons totally insane. In air conditioning bigger is not better, in fact it's the worst thing you can do. An AC will dehumidify but only while it's running. Oversized units cost more initially for the larger equipment, you will use more energy running larger motors, and they will likely short cycle (<20 min run times) which will not remove much humidity.



The only way to properly size a unit is by using ACCA Manual J. There are some sites on the web that you can use for free or low cost for 1 calculation, or you will probably have to pay a contractor to do one. If a contractor has the (expensive) software and knowledge to use it, he won't show his calculations until you sign a contract with him. This is to keep you from bid shopping another contractor that won't do the calculation. Basement loads are lower for heating and much lower for AC. There are about 20 or so factors that go into a manual J, sq footage, cubic footage, insulation above, below, and around the area, sq footage of exterior glass (doors and windows), your local climate information, area under ground / above ground, etc.



There are a number of really good minis on the market, and some are really cheap ones too. Midea, a Chinese company makes a lot of these units marketed under a lot of labels (including Carrier) and most of the ones you see in the DIY area of big box stores. Mitsubishi, LG, Fujitsu, and Panasonic all make really good units. They all offer variable speed units which I strongly recommend, they will adjust compressor and blower speeds to match the load.You can get units to support up to 4 indoor cassettes. They are very energy efficient partially because of the variable speed, and they use plastic fans as opposed to metal on traditional systems which require less torque and horsepower to run.



.
Thanks for the info. I've had a few companies out ... I asked one about a manual j and as you said they would do it but it would cost me.

I ran a load calc website with a lot of my detail.

My theater shows about 1500 btu and the rest of the basement like 24k btu

So the theater needing it's own head means I would need a 3 ton outdoor unit. A 9k btu for the theater is about as small as they make. Then a 2 ton head for the rest of the basement. Then will need to get fresh air in somehow.

One company is quoting Bryant which is midea. Are those all junk? Other place said I can pick LG or Mitsubishi.



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There will be a perfectly good pool of conditioned air in the rest of the basement. Just tap into it with dead vents as @pkinneb did. You can add a mini split for auxiliary cooling. It will save you having to configure a separate head for the theater.
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post #14 of 22 Old 02-25-2020, 06:04 PM - Thread Starter
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There will be a perfectly good pool of conditioned air in the rest of the basement. Just tap into it with dead vents as @pkinneb did. You can add a mini split for auxiliary cooling. It will save you having to configure a separate head for the theater.
He said he has dead vents and HVAC supply and return.

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post #15 of 22 Old 02-25-2020, 07:54 PM
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He said he has dead vents and HVAC supply and return.

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How many square feet are in your basement, and in your HT? Is the slab insulated? Are there any windows or exterior doors in your HT? When you did your own load calc and it asked for exterior wall sq. footage, did you count total or just what portion that was above grade. If it's below grade, it's zero. Also, the window area subtracts from exterior wall area. Don't fudge your numbers any, there is quite a bit of fudge factor built in the calculation. Unless your basement is really big like >3000 sq ft 3 tons seems too big. I had my systems replaced a couple of years ago and I'm conditioning 1800 sq. ft of basement as well as about 1400 sq. ft of first floor with a 2 ton 2 stage unit, the basement zone is set up so it will only run in low stage for heat and cooling and both areas are very comfortable. I live in a slightly warmer climate than you too. I can't over emphasize how critical proper sizing is. If the non HT section of your basement is really big, you might want to get a unit that can support 3 heads and use 2 in this area spaced out to improve circulation and reduce hot or cold spots. A properly sized unit should be able to keep humidity levels <55%.

Something to consider using a dead vent would be cost. If your calculation is correct that your HT requires 12,000 BTUs of cooling, you would need 2 fans; one supply, one return of around 400 CFM each. To keep air noise down that would require 8" round or larger ducting. If you go this route, use some linear bar diffusers to lessen air noise. Once you bought and installed all of this, added controls ,the soundproofing and additional framing and drywall you would have to do it might be only a tad less than putting a cassette in there. A seperate cassette in there with it's own control will modulate to keep up with the load. The more people in that room will increase the latent load on the AC, you would be addressing the heat gain in the room it's generated not just moving it to another area. If you already had a system in your basement, then this would be a better option.

Like I stated earlier, there are manufacturers that offer a fresh air intake but I believe only available with their ceiling cassettes. I believe it's only a 4" duct, but you do need some control over this. You don't want or need fresh air when outdoor temps fall much below 40 deg, and you don't want to bring in outdoor air when the outdoor dew point is above 65 deg. Bryant is the same as Carrier, just slightly different paint color and lower price. Carrier gets all or most of the national ad budget which is reflected in the price. They also make Payne, Day and Night, and Comfort Maker in traditional split units. The HVAC industry is loaded with relabeled products and there are only 5 or so actual manufacturers. I can't say that Midea is junk, but I would never buy one unless it was a house I was flipping and looked to sell it very soon. When they sell them at big box for DIY projects there is probably no warranty on them. Mitsubishi is an industry leader in industrial variable speed drives and industrial controls, their products are extremely durable. They probably have more technical expertise than any other manufacturer in this field.

Minis require some expertise in the install. They like to use flared fittings rather than brazed joints in their linesets, the controls set up is kind of complicated on the variable speed systems and the refrigerant charge has to be weighed in rather than using pressure/temperature or subcooling and superheat. If you go this route, make sure they send a trained and experienced tech to do the set up.

I'm assuming since you presently don't have any heat or cooling in your basement, it's not finished living space. Look at this as a home improvement instead of just cooling your HT. There might be other areas of your basement you want to finish and an additional system will give you a comfortable space to live if your primary goes out and you have to wait on service or parts. A properly sized and installed high quality Mini that is well maintained and filters kept clean and coils cleaned at least once a year should last a good 15+ years.
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post #16 of 22 Old 02-25-2020, 07:56 PM
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He said he has dead vents and HVAC supply and return.

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Correct but if you had a mini split that would replace the HVAC. Cooling and air circulation in the room is the issue more than heating it.

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post #17 of 22 Old 02-25-2020, 08:02 PM
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Something to consider using a dead vent would be cost. If your calculation is correct that your HT requires 12,000 BTUs of cooling, you would need 2 fans; one supply, one return of around 400 CFM each. To keep air noise down that would require 8" round or larger ducting.
FWIW I have two AC infinity Programmable T8 fans, Some Linacoustic RC, 3/4" MDF, and 8" flex pipe about $500 not including the bar diffusers, those things are crazy expensive to have made. Mine were about $50 a piece.
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post #18 of 22 Old 02-26-2020, 05:06 AM - Thread Starter
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How many square feet are in your basement, and in your HT? Is the slab insulated? Are there any windows or exterior doors in your HT? When you did your own load calc and it asked for exterior wall sq. footage, did you count total or just what portion that was above grade. If it's below grade, it's zero. Also, the window area subtracts from exterior wall area. Don't fudge your numbers any, there is quite a bit of fudge factor built in the calculation. Unless your basement is really big like >3000 sq ft 3 tons seems too big. I had my systems replaced a couple of years ago and I'm conditioning 1800 sq. ft of basement as well as about 1400 sq. ft of first floor with a 2 ton 2 stage unit, the basement zone is set up so it will only run in low stage for heat and cooling and both areas are very comfortable. I live in a slightly warmer climate than you too. I can't over emphasize how critical proper sizing is. If the non HT section of your basement is really big, you might want to get a unit that can support 3 heads and use 2 in this area spaced out to improve circulation and reduce hot or cold spots. A properly sized unit should be able to keep humidity levels <55%.

Something to consider using a dead vent would be cost. If your calculation is correct that your HT requires 12,000 BTUs of cooling, you would need 2 fans; one supply, one return of around 400 CFM each. To keep air noise down that would require 8" round or larger ducting. If you go this route, use some linear bar diffusers to lessen air noise. Once you bought and installed all of this, added controls ,the soundproofing and additional framing and drywall you would have to do it might be only a tad less than putting a cassette in there. A seperate cassette in there with it's own control will modulate to keep up with the load. The more people in that room will increase the latent load on the AC, you would be addressing the heat gain in the room it's generated not just moving it to another area. If you already had a system in your basement, then this would be a better option.

Like I stated earlier, there are manufacturers that offer a fresh air intake but I believe only available with their ceiling cassettes. I believe it's only a 4" duct, but you do need some control over this. You don't want or need fresh air when outdoor temps fall much below 40 deg, and you don't want to bring in outdoor air when the outdoor dew point is above 65 deg. Bryant is the same as Carrier, just slightly different paint color and lower price. Carrier gets all or most of the national ad budget which is reflected in the price. They also make Payne, Day and Night, and Comfort Maker in traditional split units. The HVAC industry is loaded with relabeled products and there are only 5 or so actual manufacturers. I can't say that Midea is junk, but I would never buy one unless it was a house I was flipping and looked to sell it very soon. When they sell them at big box for DIY projects there is probably no warranty on them. Mitsubishi is an industry leader in industrial variable speed drives and industrial controls, their products are extremely durable. They probably have more technical expertise than any other manufacturer in this field.

Minis require some expertise in the install. They like to use flared fittings rather than brazed joints in their linesets, the controls set up is kind of complicated on the variable speed systems and the refrigerant charge has to be weighed in rather than using pressure/temperature or subcooling and superheat. If you go this route, make sure they send a trained and experienced tech to do the set up.

I'm assuming since you presently don't have any heat or cooling in your basement, it's not finished living space. Look at this as a home improvement instead of just cooling your HT. There might be other areas of your basement you want to finish and an additional system will give you a comfortable space to live if your primary goes out and you have to wait on service or parts. A properly sized and installed high quality Mini that is well maintained and filters kept clean and coils cleaned at least once a year should last a good 15+ years.

Basement will be about 1,300 sf total finished space when finished.
HT will be about 350 sf of that. so remainder around 1,000 sf.
Bare concrete floors right now.
HT will not have windows, only a door which will be sealed/soundproofed somehow.

The loadcalc.net asked for specifics on walls above/below grade, windows etc. i filled it out best I could.

HT was only like 2k or 3k btu for cooling HT, and about 1k btu for heating the HT

Plan is to leave current HVAC alone for the upstairs and not tap into it, 1 for noise and 2 for its sized already for the upstairs.

So I'm back to if I put a small head like 9k btu in the HT and a large head in the rest of the basement like 2 ton. how do i get fresh air in the HT without doing something super expensive/difficult
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Let's start with a couple of questions. How many sq ft on the main level of your house? What size AC supplies that floor? If you don't know you can go outside and take a pic of the nameplate, or jot down the manufacturers part number and post it here. All manufacturers embed the size in the part number, different places with different manufacturers, but I can tell you from the part number. You should never need more AC in the basement than above ground unless you are running a ceramic kiln, forge, or a still in your basement.

I'm assuming (yes, I know what it means) that your basement is totally unconditioned now. What is the comfort level, temp and humidity down there on the coldest day of the year and the hottest day of the year. I'm also assuming that you have no issues with frozen pipes. If it's tolerable, that should give you an indication of how little heating and cooling you might need.

You stated that your online calc showed that you needed 2K-3K BTU of cooling for your HT. A ton of cooling is 12K BTU, so your calculation shows about 1/4 ton needed for your HT. I can't imagine the entire basement needing more than 1 ton total. A 9K BTU mini split head in your HT will be 3X oversized to start with. I do have an idea how you can tip toe into this and be relatively inexpensive. Start by building the hush boxes with inline fans, 1 for supply and 1 for exhaust in your HT. Try to get as much separation as you can between the 2 so you actually get an air exchange rather than just recirculation. These will work regardless of what you do in the remainder of the basement. At 350 sq ft, I think something in the 200 CFM range will be plenty. Fantech, Aldes, Soler & Palau, and others make some high quality inline fans. If you have a window in the basement that will allow a window shaker AC to be installed, get a 12,000 BTU window unit. Set the temperature to whatever you want, just leave the fan on all the time. If you could set up the hush box fans to run 15-20 minutes per hour when not occupied it would help with circulation and keep the room fresh and cool. If this experiment works out you can be confident that a 1 ton mini with 1 head in the larger part of basement will fulfill your needs.

As far as fresh air intake, you might already have all you need. I don't know the age of your home, but all homes leak air, the older the more likely. The only way to know for sure is to have a blower door test done. If you don't measure, you're just guessing. If the leakage is high enough, a simple bathroom type exhaust fan exhausted to the outside operating on an interval timer will allow enough fresh air to infiltrate through building leaks. This would be the least expensive and least desirable way to go. There are a number of fresh air intake devices available, mostly ducted from the outside with a powered damper operating on an interval timer. These are relatively cheap, but are designed to feed into the return on an air handler where it mixes with the conditioned air. This is not an option for you since you don't have an air handler serving your basement. Another option would be an ERV (energy recovery ventilator), the premise for an ERV is that it will exchange an amount of indoor air with an equal amount of fresh outdoor air. All of them require some ducting, power and controls wiring. These run a broad range of capacity and price. One that I believe would suit your needs is a Panasonic Whisper Comfort Spot ERV it has a range of 10-40 CFM and is rated to serve a 1700 sq ft 3 bedroom house. Panasonic ventilation products are awesome. This one only has 2 4" ducts and should be very quiet. The indoor unit can be ceiling or wall mounted, where ever you can best hide the ducts. If you go this route, please contact me, there are outdoor conditions where temperature and humidity on either end of the range where you do not want to bring outdoor in. There are some fairly inexpensive controls that will do this and they will require an outdoor sensor that will require wire pulled for before you finish the ceiling and the wall it will be mounted on.

If humidity is an issue in your basement, another option would be a ventilating dehumidifier. These will dehumidify and bring in fresh air controlled individually. Some quality brands for these are Ultra Aire, Honeywell, and Aprilaire. These require some ducting and produce condensate that has to be drained or pumped away. These are rated in pints per day for the amount of humidity it can remove. Most of the ventilating models start around the 80-90 pint per day range.

I hope this helps.
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post #20 of 22 Old 02-26-2020, 06:03 PM - Thread Starter
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So first thanks for taking the time responding with such detail....

My house is about 3400 sf colonial in Detroit area. AC is a 2 stage 5 ton. Furnace is 120k btu I believe variable speed. About the biggest residential stuff Bryant makes.

Basement currently has 4 vents in the ceiling with no returns.

Right now about half of the basement is framed around the perimeter with 2" of closed cell spray foam.

Walkout wall is basically a 13' tall x 19 wide wall of windows and a doorwall. But haven't framed or insulated the half of the basement nearest the walkout.

In the dead of winter it's about 63 degrees away from the walkout area and about 52 close to the windows.

Summer time it stays cool.... no real need for much AC....other than probably in the HT when built.

Humidity is not really an issue.

A window unit is not an option. I know that the 9k unit is 3x needed but that's about the smaller they make. Plus that doesn't account for a projector...amps...and potentially 10 people maybe once in a while.

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post #21 of 22 Old 02-28-2020, 05:02 PM
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Originally Posted by thisismyname123 View Post
So first thanks for taking the time responding with such detail....

My house is about 3400 sf colonial in Detroit area. AC is a 2 stage 5 ton. Furnace is 120k btu I believe variable speed. About the biggest residential stuff Bryant makes.

Basement currently has 4 vents in the ceiling with no returns.

Right now about half of the basement is framed around the perimeter with 2" of closed cell spray foam.

Walkout wall is basically a 13' tall x 19 wide wall of windows and a doorwall. But haven't framed or insulated the half of the basement nearest the walkout.

In the dead of winter it's about 63 degrees away from the walkout area and about 52 close to the windows.

Summer time it stays cool.... no real need for much AC....other than probably in the HT when built.

Humidity is not really an issue.

A window unit is not an option. I know that the 9k unit is 3x needed but that's about the smaller they make. Plus that doesn't account for a projector...amps...and potentially 10 people maybe once in a while.

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Yet another idea. I believe the reason a manual J load calculation will never be accurate is because you are going to be conditioning air that is already partially conditioned. You said that the interior of the basement during heating season it stayed around 63 deg thanks to the 4 supplies off of your main system. Depending on what your comfort point is, you only have to raise the temperature <10 deg. I doubt that in any version of manual J software the algorithm takes this into account.

My latest idea is to install a 1.5 ton heatpump for your basement, nothing exotic, just a single stage heatpump and an airhandler. I believe the controls can be set up to make your HT work more like a demand driven system. This will require some duct work. A conventional lower end heatpump will be less expensive than a mini.

The heat gain for your projector and amps as well as the people is pretty easy to calculate, I'll show you how if you are interested. Not knowing your budget (none of my business), if you think this is worth looking into please respond and let me know. I don't want to ramble on for a long time if you don't think this is a viable solution.
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post #22 of 22 Old 02-28-2020, 05:11 PM - Thread Starter
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Yet another idea. I believe the reason a manual J load calculation will never be accurate is because you are going to be conditioning air that is already partially conditioned. You said that the interior of the basement during heating season it stayed around 63 deg thanks to the 4 supplies off of your main system. Depending on what your comfort point is, you only have to raise the temperature <10 deg. I doubt that in any version of manual J software the algorithm takes this into account.

My latest idea is to install a 1.5 ton heatpump for your basement, nothing exotic, just a single stage heatpump and an airhandler. I believe the controls can be set up to make your HT work more like a demand driven system. This will require some duct work. A conventional lower end heatpump will be less expensive than a mini.

The heat gain for your projector and amps as well as the people is pretty easy to calculate, I'll show you how if you are interested. Not knowing your budget (none of my business), if you think this is worth looking into please respond and let me know. I don't want to ramble on for a long time if you don't think this is a viable solution.
Well the basement is 63 in areas away from the windows and yes there are 4 vents....but the plan is to close off those vents and give the basement it's own system. Mostly because the area near the windows is so cold and the ceiling there is 13' high....so the ceiling vents don't do anything for the floor, and there will be no interior walls to run duct work down. Also the HT, dont want ducts in the HT, so....I got some quotes on the mini, multi zone with 1 head in the ht and 1 in by the walkout area. think im just gonna run with that.

Talked with ted from soundproofing co and he said they always recommend a ductless mini in a soundproofed room with no other fresh air system other than the door to the room opening on occasion to bring in fresh air.
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