What the h&ll should I do with my HVAC?!

[NNF]

Hi there,

First post here! I hope to get some advice from all the experts here to help me make my mind up on what I should do with my HVAC

So we live in this 1950s era house, 1750 sq ft, single level. The furnace is 10yr old and seems to be working ok. It's a Carrier WeatherMaster 8000. No cooling. Ductwork is obviously leaking (black discoloration of insulation) and only one return. Moderate (ish) SF Bay Area climate but we do get quite a few weeks >85F in the summer and a couple of weeks where the nights drop <40F.

So what's wrong..sounds fine doesn't it!?!

Well I need to put in some form of cooling / ventilation for a home theater room. That's the main thing prompting me to do something. The room is going to be air sealed for sound isolation and so the existing supply is not going to be enough. Plus there is no return...and anyway there is no cooling in the house! Room is 12x17x8, will be used by 4 people max for say 3 hr at a time. There will be equipment in the room and a projector. Both of which throw off quite a bit of heat. This particular room has very good access, from the back it borders on an attic space, there is also a small attic above and below is the garage, so running new ductwork is not an issue. The kicker is that I need a very low noise HVAC for the theater. <30dBA is the target.

I've called 4-5 local HVAC contractors, and they have been over to my home. The proposals range from 'install a minisplit'...though none of them have a good response when I say 'what about ventilation'? Through to 'get a top of the range modulating furnace, new HVAC, zoned dampers, ductwork, etc' (basically new everything). Seeing as we are going to be in this house for a while I like the idea of spending money in a way that's going to give something useful beyond the theater. If the theater costs $5k for a separate system and a new system for the whole house (with cooling, quiet furnace, new ductwork etc) is $15k then I'm leaning towards the more expensive option.

I do want to be sure, however, that whatever system that is installed is going to be quiet enough for the theater. That is priority 1.

If you guys and gals were in my situation what would you do? And how would you choose a HVAC contractor?

[jtrammel]

A mini split will work well for the theater room as you can turn the unit on only when you plan to use the room and they are quiet. as for ventilation you should be able to bring in outdoor air and exhaust using a small bathroom exhaust fan if truly necessary, I doubt the room will be sealed that tight IMO but could be if one wanted to. As for the rest of the house I would reccomend all new ductwork furnace and ac. 14/15 SEER ac and 95% or better furnace and possibly a whole house dehumidifier. That's what I would do if it were my house.

[dan sw fl]

Hi there,

First post here! I hope to get some advice from all the experts here to help me make my mind up on what I should do with my HVAC

So we live in this 1950s era house, 1750 sq ft, single level. The furnace is 10yr old and seems to be working ok.

Well I need to put in some form of cooling / ventilation for a home theater room. That's the main thing prompting me to do something. The room is going to be air sealed for sound isolation and so the existing supply is not going to be enough. Plus there is no return...and anyway there is no cooling in the house! Room is 12x17x8, will be used by 4 people max for say 3 hr at a time. There will be equipment in the room and a projector. Both of which throw off quite a bit of heat.

The kicker is that I need a very low noise HVAC for the theater. <30dBA is the target.

... proposals range from 'install a minisplit'...though none of them have a good response when I say 'what about ventilation'?

If the theater costs $5k for a separate system and a new system for the whole house (with cooling, quiet furnace, new ductwork etc) is $15k then I'm leaning towards the more expensive option.

I do want to be sure, however, that whatever system that is installed is going to be quiet enough for the theater. That is priority 1.

If you guys and gals were in my situation what would you do? And how would you choose a HVAC contractor?

I would use a ducted min-split with remote FanTech exhaust fan to maintain the less than your small budget.


Of course, if any noise becomes an issue, I'd turn up the volume.

Just KIDDin.

NuTone is a good alternate.
http://www.nutone.com/product-catego...egoryID=200161

Add solid state control for further speed / noise adjustment.
http://www.nutone.com/PDF/Specifications/99044772B.pdf

[motoguy128]

You do realize that the fan o nteh rpojector is probably around 40db uless it's a special model. Wait a coupe years until the bearing gets noisy on the fan.

THe people and video equipment will add about a 1/2 ton to hte heat gain of the room.

IF you keep duct velocities low <500fpm, use flex duct and use oversized commerical quality registers and duct noise should be well within your range.

Use

[Tommy knocker]

Mini split and a fart fan mounted outside space with 4" flex run to it with a couple sweeping turns. For fresh air just get up and open the door for a second. Doubt you can get room tight enough to need to though.

[NNF]

I would use a ducted min-split with remote FanTech exhaust fan to maintain the less than your small budget.

I like the idea of a ducted mini split. How does the ventilation work? Do you add an air intake on the return side of the ductwork from the room to the mini split? Where does the exhaust fan go - just on another isolated piece of ductwork from the room to the outside or somehow connected into the mini split ductwork?

[NNF]

Thanks for the replies. Seems you are all pro mini split.

Would you advise against a zoned system with the theater on separate zone? This has been suggested as a solution by one company. Theater is 200 sq ft vs whole house 1750 sq ft.

[jtrammel]

mini splits don't have duct work they hang on the wall and pull return and blow supply similiar to a window unit. They do make ducted mini splits but the most common are hung on the wall like a picture.

[Tommy knocker]

Thanks for the replies. Seems you are all pro mini split.

Would you advise against a zoned system with the theater on separate zone? This has been suggested as a solution by one company. Theater is 200 sq ft vs whole house 1750 sq ft.

Not gonna advise aginst whole house upgrade with zones. However to do it rite your not just talking about new equipment. It will be a very significant investment. If your ready to drop alot of cash and can afford it the reasons to do it are numerous. However if your thinking $10k or less then mini split and a fart fan probably better option. You can get new equipment and zones on the cheap but you will get what you pay for. Good luck.

[Kevin Weaver]

Mini split units are so quiet you wouldn't know it was on. Buy a heat pump one, and it can heat too. Fijisu makes a good one with inverter compressor technology.

[martyinlincoln]

If it were my house I'd stick a mini split in the room and add a return to the main system. Probably would stick a switch in the room to bring on the main blower while occupied.

[Bsmith816]

We have put a few of the Lennox MS7H mini split heat pump systems in. They are very nice and super quiet. They also have the variable drive compressor.

[54regcab]

+1 for the Minisplit. Open the door for ventilation if needed.

[NNF]

The door needs to be closed during use...otherwise too much sound leakage in / out! Therefore ventilation definitely required.

I think I will go for a ducted minisplit where the air handler is out of the room e.g. Mitsubishi / Fujitsu with a fresh air intake. Seems like the ideal solution.