CO2 is slightly heavier than air and can be dangerous because it will “pool” on a floor from say a soda fountain leak. You mentioned it is a 4 level house. Perhaps over time with no ventilation the...
Type: Posts; User: hvac n-j-near
CO2 is slightly heavier than air and can be dangerous because it will “pool” on a floor from say a soda fountain leak. You mentioned it is a 4 level house. Perhaps over time with no ventilation the...
Poor man's heat recovery!:grin2:
KK2 – Glad you got your situation corrected. FYI – ASHRAE 170 Ventilation of Healthcare Facilities is a part of Facility Guidelines Institute (FGI) which is code in may states has a section on air...
We often assume things that are clear in our mind, but may not be as clear to the folks looking at the documents.
Typically I would describe the duct and elbows as you mentioned with a note to...
I have designed and renovated a few data centers and they can be difficult to “right size”. Keep in mind your ME is doing what I would do in covering the entire input KW if they do not know any...
Your engineering guys really need to engage the help of a design engineer and get a handle on how much heat the equipment is dissipating and what the climate will be. If it's getting that hot then...
As others have said – Yes and No
It is not just a plug and play type of thing. The whole system needs to be evaluated by an engineer.
For example: If the cooling tower is oversized then perhaps...
There is really no rule of thumb for pressure drop on this type of equipment.
Also, You will need to size the pump head to be at least the pressure drop of the entire system. This would...
Could condensing furnaces be used since they are designed to handle the corrosive condensate?
I assume that's the manufactures low entering air concern. That would be more expensive hardware,...
if you can measure the enthalpy (temp and humidity then calculated from psych chart) of the supply and return air and convert CFM to pounds of air, the total cooling (BTU/HR) will be the pounds of...
Fire dampers must be installed exactly as indicated in the manufacturer’s instructions in order to achieve the required fire rating. Some have angle on one side of wall or other variables regarding...
Not sure of the weather conditions in the northeast, (I’m from the hot/humid southeast) but any time you bring in outside air in cool humid weather, it should be pre-conditioned to remove moisture. ...
The 1st space has a space temperature of about 70 and the cooling coil discharge of 58.2 and the chilled water valve is 23% open. This equates to a space RH of 66% without taking into account the...
I agree with Mikey. 13,000 CFM of outside air in VA is 65 or more Tons of cooling by itself and much of that load is dehumidification.
The make-up air for the paint hoods should be separated...
ASHRAE Fundamentals Handbook chapter 18 has a good bit of data on heat load calculations. Computers and Office equipment loads can be highly diversified and are a function of their use or output. ...
This is a bit of a difficult concept to see, but both pesmsg and R123 are absolutely correct the decoupler should not be controlled. The Primary loop flows by itself as does the secondary. When the...
You can always inform your client that you will sort through, clean up, cut, re-braze, chemically clean the inside, re-insulate, purge, NOT warranty the refrigerant part of the install due to the...
Rider is correct. I am not a tech, but I pay attention and I have family that has owned beach property for quite some time. I believe York makes phenolic coated coils and stainless steel housing,...
Now your going to have to add more tape to that splice AND tape up the panel cover!
No problem, let us know how it turns out. Others may chime in later today with more info. There are some very experienced folks on this forum. If your not in a big hurry.
I don’t believe it would be a problem but I’ve never actually seen a situation like this. Even if it formed a perfect vacuum which it will not, there would only be atmospheric pressure on the...
The safest thing to do is make a ½ or ¾ hot tap and install a vacuum breaker to take care of it, this is what I would recommend. If you are confident the valves will hold you could shut it down, let...
What steam pressure and pipe size and type is it and how long? Also, what is the route, one long run or does it have elbows, offsets etc?
Typically it is desired to have the kitchen negative to the dining spaces, etc. and the overall building at a slight positive to avoid infiltration from unexpected places. Looks like you are about...
I highly recommend engage an engineer in your area to verify what codes are in effect and assist in other HVAC requirements. That said ASHRAE Std. 170 – Ventilation of Health Care Facilities is...
So it appears your loop controlling the discharge temperature is reacting too fast and the heating valve closes too much in trying to reach the return air temperature set point. You can set the loop...
If you have ASHRAE Fundamentals 2009, there is a chart on page 26.3 with info on air spaces based on thickness, orientation, etc.
You may have relief air with higher humidity (in winter) being blown onto the roof but in cooling mode I don’t think any process will raise the outside humidity.
My guess is that you have a...
Some mini manufacturers (Daikin I think) make water cooled condensing units which should not be affected by low ambient temperatures. They would require year round chilled or condenser water. Not...
If you are referring to poly-urethane duct material, most systems like this are not allowed in hospitals due to their flammability ratings.
In most situations where galvanized duct is not used,...
I do not have anything official. You could probably do a web search on the topics and come up with something.
Total all the heat sources in the Electrical room. Typically this is transformers. Transformer heat output is approximately:
Heat Output = KVA * % Loaded * (1-EFF) * 1000
Where: KVA= the...
Are you looking to ventilate for cooling of the space? There are some rules of thumb for that.
I agree with dlove (and I am an engineer by the way.) There may be some design restrictions I am not aware of, but..... One RTU per theater and one (or more) ERVs to handle the outside air separate...
Don’t know how much space you have to work with, but one method I have seen work in the past is to connect the sensor to the outside with a long (20’) piece of 2” pipe with an elbow on the outside...
Looks like you need to be asking the contractor that installed it what the design intent was, if any.
Depending on where you are it can vary a great deal. Here in the southeast a design could...
Your township inspector has probably been to a seminar or read an article on Hydrogen.
Not sure what code you are under there, but the 2009 IMC section 502.4 indicates the hydrogen limit must be...
What is driving the requirement for the 3 filter banks? Is it a code requirement or an engineering (or other) spec item? If it’s a spec from an engineer I’d ask what their intent is.
Otherwise...
19Character is correct, you described a displacement ventilation system. It’s a new way to try to improve comfort and reduce energy. Go to Price’s website (http://www.price-hvac.com/) and search...
Psiman is on the right track. The leakage from your room(s) is a function of the total area of all the cracks in the room. Unless you can measure these (the cracks around doors, windows, electrical...
Desert Aire is a reputable manufacture. They have very good design procedures which will give a good selection. Make sure you and the owner are aware of the design temperature of the room and the...
TB - You make my fingers cramp up just reading your response.
Great answer - You have a way of converting engineering into everyday language. I hope you teach somewhere.
Excellent question, and the discussion shows just how stupid government regulations can be sometimes.
If you charge a system with canned air and then vent it, ethically you have done nothing...
The requirement is pretty much standard for hospitals and ORs in particular (ASHRAE std. 170 - Ventilation of Health Care Facilities), but it is a range: max of 60% and min of 30% with the...
I am working with an owner who has a new York/JCI 850 Ton, Variable Speed centrifugal chiller (model YK). The compressor shaft seal is a “wet seal” and I understand that this requires some oil to...
I am working with an owner who has a new York/JCI 850 Ton, Variable Speed centrifugal chiller (model YK). The compressor shaft seal is a “wet seal” and I understand that this requires some oil to...
Ditto what DoE said. Very difficult to reach those conditions with regular DX (or standard chilled water) equipment!
Put a piece of tissue at the gap under the door and see which way it goes.
It appears the fan is trying to do more than 1/3 hp worth of work.
Are you sure the new motors are the same RPM as the original?
Do you have more info on the fan? The 100R2B does not ring...
Not that you need anything else to worry about, but with the make-up air off and the exhaust fans for restrooms, etc. running your building is negative so it’s pulling air from somewhere you can’t...