08-04-13, 11:16 AM | #1 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
|
Vent-Miser 91668 Programmable Enery Saving Vent
This device seems like it might be good for saving a few bucks,
if you have an old style Central HVAC system.. Draw-back, you need one in each low-occupation room.. vm - YouTube Amazon.com: Vent-Miser 91668 Programmable Enery Saving Vent, 12-by-6-Inches: Home Improvement
__________________
My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. |
08-04-13, 05:14 PM | #2 |
Less usage=Cheaper bills
Join Date: Nov 2010
Location: Minneapolis, MN
Posts: 939
Thanks: 41
Thanked 116 Times in 90 Posts
|
Old style central HVAC? Central HVAC is the current standard that almost all houses have installed today.
This doesn't seem like that good of an idea. If it is a low occupancy room, just shut the vent. If you use the room some of the time it would take quite awhile to match the same temperature once the vent gets opened as that room isn't going to recover from the 'setback' as fast as the rest of the house. This thing is a bit pointless IMHO. I also have issues with airflow requirements too, seems ductwork is small enough in houses as it is, choking it off more isn't such a great idea for most systems. Also zoning usually shuts off the supply, not the return vent. Either way, if you don't shut off both you'll still get air exchange that will likely not accomplish the objective and the savings would likely be minimal. Last edited by MN Renovator; 08-04-13 at 05:22 PM.. |
08-05-13, 06:29 AM | #3 | |
Helper EcoRenovator
Join Date: Mar 2013
Location: 245862
Posts: 43
Thanks: 12
Thanked 3 Times in 3 Posts
|
Quote:
I asked the HVAC guy that maintains my system, he said the more air moving the better. He said since my house isn't that large it wouldn't save much if at all. He told me if you restrict the supplys and/or returns in enough rooms it will reduce airflow which can cause the evaporator to accumulate ice which would reduce efficiency and eventually cause the AC to quit working until the evaporator is thawed out. |
|
08-05-13, 08:21 AM | #4 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
|
The target home has a very poorly installed system.
Very little cooling makes it to the two second floor bedrooms. (these are add-on rooms). It looks like the old system was replaced with a newer R410A system, around the time of the second floor and Great Room additions. Before the house was purchased, I inspected it and reported the central cooling and heating system was about 80% nonfunctional, and appeared to have been installed by highly untrained chimps. Of course that part of the report was ignored. The 'new' system had been installed without any Return! So it worked very poorly. The return intake was on the very bottom of the indoor unit. There was no bottom plate in this unit. It was wide open. The floor underneath the unit was a mess, since the system was working like a shop vac, cleaning the floor in the equipment room. The area in front of the unit was so cramped, there wasn't room to remove the washable plastic 'filter' (a simple screen). So, it had never been removed and cleaned. Air came in via plastic screen filter 1/3" off the basement floor. The center of the filter was drooping down touching the floor. The filter had to be bent in the middle to remove it. The unit had been installed on 4 'blocks', to lift it off the floor and allow air to flow underneath it (and be pulled up thru the filter). But, those 'blocks' were just the shipping foam from the shipping carton. They had compressed, so the small in-take path was now down 1/4"w x 16" long. The system was mess. A quick make-shift Return worked. Operation improved greatly by opening the equipment room door and the basement stairs door. It was improved even more by the addition of an actual Return input. (Left side input, using a real filter). The system is now working.. The main problem now, is a lack of cool AC air flow upstairs in the Master BR. The duct is so long, lossy and leaky (inside the walls, inaccessible), the cool air flow in the MBR is very weak. ~~~ I think more air could be pushed upstairs, via manipulation of some of the Return paths from other rooms. By closing two of the downstairs bedroom doors, and maybe one upstairs, cutting off their returns.. The rest of the rooms will see more cool air, since those closed rooms will just pressurize and not be hogging AC air.. The two main hi-output vents are in the LR where the Tstat is located, those would never be touched. So, it seems like the timer operated vents won't be needed, if the owner can remember to shut some bedroom doors downstairs before bedtime.. I've been thinking those timer vents could be hacked, so they only cut the air flow down by half or 3/4.. Or, just shut the door..
__________________
My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. |
08-05-13, 10:07 AM | #5 |
Less usage=Cheaper bills
Join Date: Nov 2010
Location: Minneapolis, MN
Posts: 939
Thanks: 41
Thanked 116 Times in 90 Posts
|
..more of the reason that any house I ever build in the future will have heating and cooling accomplished with mini-split heat pump(s). No worries about ductwork losses, carbon monoxide concerns, and an install that I would potentially do myself and save plenty of money by not dealing with extensive ductwork design that will likely not be done extensively like it should be. Then again I'm planning on building small, super insulated, and geometrically simple, so with that sort of plan even the smallest condensing furnace sold today (40k BTU) wouldn't even run for 10 minutes over the period of an hour during the course of the night. With that kind of load you can heat one area of the house and since you aren't battling heat loss from everywhere else, the heat transfer is enough to where it remains comfortable everywhere with a single point source. The only challenge is two floors because heating is best accomplished downstairs and cooling is best done upstairs although good insulation and air sealing should keep temperatures comfortable enough via convection even with heating only upstairs as long as there aren't shut doors in the way. I'm planning to build single story slab(insulated) on grade to avoid loss of square footage and design challenges that stairs add and the HVAC challenge. Not to mention that I prefer to build a house that I could grow old in and not need to think about dealing with climbing stairs when age makes it difficult.
|
08-05-13, 04:43 PM | #6 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
|
Those mini-split friendly houses??
Yeah, for a smallish house, mini-splits are just the thing.
Even a large single level home, could be well served with MS HPs. I think one of the main problems with two story houses is the cold wanting to stay downstairs and the heat wanting to float upstairs. Stairs are the problem. I never see any with doors, to control AC air flow. Heck, they have basement stairs, why not door the stairs to the second floor? Thermal curtain maybe? People aren't interested in trying new things. Took many months to sell my wife on the first Sanyo. The very ideal if pulling 20 or 30k BTU out of outdoor are that's 12 deg F, is a bit much for most people to believe. Sounds crazy to many. I had to actually install that Sanyo, and put my hands under the vent, when it was 10 or 12 deg F outside.. Then, I became a firm believer. Seeing a warm house at 5 deg F was exciting too! Although, it's a rare event when you live 12 miles from Boston harbor. If things go bad around here and I have to move, I'm going to try to move into a place that's mini-split friendly..
__________________
My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. |
08-06-13, 11:53 AM | #7 | |
Helper EcoRenovator
Join Date: Mar 2013
Location: 245862
Posts: 43
Thanks: 12
Thanked 3 Times in 3 Posts
|
Quote:
I'm not saying the product doesn't have a use I was just saying you would have to be careful where you install it and how many also to do research to make sure your investment is actually an improvement. Something like that wouldn't benefit me due to the construction of the house and the type of system I have but if you have a larger house it might be better. |
|
08-06-13, 12:33 PM | #8 |
Lex Parsimoniae
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
|
It would very easy to find out if they would work for you..
Just manually close and open the vents in the selected rooms and see how it works.. If you like the results, keep doing the manual op, or go full auto.. With AAA batteries!
__________________
My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. |
11-09-13, 08:14 AM | #9 |
Apprentice EcoRenovator
Join Date: Nov 2013
Location: Moore Oklahoma
Posts: 267
Thanks: 108
Thanked 23 Times in 21 Posts
|
The problem with cutting airflow at the registers are noise and increased duct leakage. If you want to zone get a zone damper.
|
|
|