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HVAC is a good business to be in, have you seen some of the huge Building Automation and Control Systems out there by outfits like Siemens? Incredible stuff. Not just the HVAC but entire building as in skyscraper systems.
Sorry guys, I haven't been able to reply because of the holiday madness. You guys are awesome! Your input has been great and helpful. There were many forums to choose from in my Google search and it seems I chose the right one.
As far as the HVAC business goes, you are right, it is a great business to be in. I am a service tech and enjoy working on commercial refrigeration like walk in coolers and freezers and ice machines. I just like fixing stuff.
You are right about the controls and building automation. It has become increasingly more complex and I would love to get into more of it. Besides, working on controls is a lot less physical than lugging 5 ton compressors, recovery units, welding rigs, nitrogen tanks, refrigerant tanks and all the other tools on to a commercial building two stories up via a rope.
Back to the problem at hand. All these ideas are great and would work wonderful but unfortunately the customer doesn't want to invest to much more than what he has already spent. The part that really frustrates me is that the thermostat has these features built into it already but because it is designed to allow the user to press the override button up to eight times which is 4 hours it becomes an issue. One press, one hour, thats it. There should be a setting in the advanced set up to control the override duration.
I purchased a little media player that you can hook up an external drive to and then connect it to your tv to watch movies off of your hard drive. People figured out a way to hack the player to allow mods to be done to it. To bad it wasn't that easy.
I must have missed the last post with the link to airotronics.com. I believe that would work great but there are about thirty on that page. I think the terms that are being used are confusing me. Would the TGMT be the way to go. The timer function works without voltage applied. Or would a one shot work better.
TGMT - They are unusual timers and the time isn't long enough. So No.
One of the better ways is to make a phone call and talk to the rep explaining what you have to do and what they would recommend to be the least cost option. A DIP switch usually costs more, but the "resistor" if needed, you have to source somewhere else. The 24 VAC, the dry contact (NO or NC) requirement and the approximate 60 min timing, low cost etc. The DIP switch makes it easy to change the interval, so I would get prices and delivery for both.
I'll guess that your looking at $25 to $80 each. Yep, still messy.
The 60 min time isn't unusual. One would expect the "responsible adult" to hit it once or hit it for the expected time that one is going to be working "after hours". It does indicate that it's been hit.
A fix for 5 is not the same as a fix for 500.
The Carrier stat (unusual company), offers 15 min intervals, but I forget the maximum time ad hold indefinitely.
I am going at some point use a Vision Pro stat to create ersatz zoning in a laundry room. No duct there now. I have MOST of the parts. But occasionally, I'd like the clothes to dry faster or it to be cooler when the AC is on. The caveat is that the state of the register damper has to be either OPEN or CLOSED between say for 20 minutes or so around 1:00 Pm when the system does it's filter static pressure check.
The stat needs to have easy way to select 12 hours to a day max, and sometimes less.
Glad you like it here. I was very active in another forum on multiple boards (multiple topics) until an incident. I chose to leave because I was told that the mark would never be erased, but I was never "banned". I had some moderator privs there. I'm highly rated here and was there too.
One of the things I recommend to my customers that complain that one person is freezing and everybody else is hot is to install a zone damper on one duct run only. All you need to do is install a 24v AC transformer and a separate thermostat for the room you want to control separately. Determine what size the duct run is for that room and get a motorized zoning damper and install it somewhere in the duct run. The thermostat will not turn the system on or off but instead open or close the damper when the room reaches the set temperature for that room. If you are going to do this to a large room with a duct size over 8" then you will more than likely need to install a zoning system which incorporates a barometric bypass damper that allows the excessive static pressure to "dump" back into the return plenum. It gets pretty complicated at this point because when you dump heated supply air into the return you increase your supply temperature to a temp higher than the high limit of the furnace which shuts it down. For the a/c side of the zone system when you close one zone off the excess air is dumped back into the return and now the evaporator will freeze because there is not enough heat load. A low ambient control can be installed at the condenser to cycle the condenser fan motor to keep the head pressure up to prevent the evap from freezing.
In my opinion zoning systems are not the way to go and I don't care for them but using one zone damper on one duct run could be the solution without creating a different problem.
Yea. The laundry room used to get heated by the inefficient furnace. Now it gets outside air with a 98% eff furnace. No returns. carrier recommends no bypass dampers with their zoning systems. The stat is aware of the duct static pressure. I won't have their zoning control, but I'm sure it will change blower speed based on static pressure. Blower is continuously variable. RPM is also available at the control.
Their "true filter" system wants sets all zones open and measures the static pressure (through the motor interface) at 1:00 PM everyday for about 5 minutes. The initial SP is taken at reset. So, when the static pressure changes by x % (who knows what that is), the filter needs to be replaced. The stat will warn you and is the interface for the reset.
The stat also accumulates an error history in Human readable form. It also knows the BTU's of the furnace and AC and outdoor air temperature.
I'm using an Aprilaire 5000 filter (media + electrostatic), mounted on it's side at the ceiling to conserve space.
I'm familiar with Carriers Infinity system. I worked for a Carrier dealer for 15 years. Carrier is a good brand, but over priced. I'm all to familiar with the ECM blower motor that you are describing. The Infinity is a completely different furnace than what I was referring too in the previous post. You should be able to change the frequency of static pressure checks. Everyday seems a little much. The way I remembered it was the furnace is always checking the static pressure when it's running and if it is to high it would display an error or warning about a possible restriction. You say there are no returns and I find it hard to believe. The furnace has a sealed combustion and gets its combustion air usually through the same pvc flu pipe. The inside of the pipe has a smaller pipe in it, one is intake and the other is the exhaust. I've only seen a few instances where you would bring in 100% outside air with no returns. It kind of defeats the purpose of having a high efficiency furnace if you are not reheating the air inside the house. I mean some fresh air could be brought in to the system but 100% is odd. If you have an air conditioner installed too then you are going to have a hard time cooling anything with no returns.
That may have sounded like I was referring to combustion air and return air as being the same, its not ofcourse. The 100% outside air may be the combustion air you are referring to.
Yea 100% outside air for combustion, but no hot/cold air returns in that particular room. In a house you generally put the returns on louvers and change to the ceiling ones in the summer and the floor ones in the winter.
The water heater has inside air for combustion and therefore there is a grate on the door, so the water heater can get it's air with the door closed.
The Infinity will also control the humidity in the house. Just set the percentage and it will maintain it. Very Nice Furnace. Those ECM motors are a bit pricey if not covered under warranty. We seem to have strayed from the original topic and if we keep going they might have to change the topic again, lol. Thanks again for your input.
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