I've been sizing domestic, hydronic, sewer, and natural gas for years but this is the first time I've had to size medical gas. Having a bit of trouble finding the right resource.
Thanks,
This is how I'd like to pipe in a new heat exchanger into the existing building system. The pump shown is variable speed. I'm concerned that the higher pressure HWS upstream water will push more water through the pump than required when the pump is running at low speed. Do you think this will be...
I've seen that manufacturers tout HVLS fans for summer use by saying they have a cooling effect that can make people feel 10 degrees cooler than without it. But wouldn't it also destratify the warmer air near the top of a warehouse and bring it down to floor level? Pretty much cancelling out the...
I'm trying to figure out how much exhaust CFM I would need to provide to cool an electrical room with transfer air from surrounding spaces. It has a 115 kVA transformer inside; it looks like these are typically about 95% efficient so 5% would be given off as heat in the room. So I'm looking at...
I know the title sounds a little silly but that's what it comes down to at the present moment.
I think I might need to make more money, considering a career change. HVAC engineer (PE) currently; looking for advice and experiences.
Hello, my wife and I just went through our finances in detail...
I've heard all the rules of thumb, over 30 psi, over 15 psi, if it's connected to a boiler system over 200,000 BTU/hr or over 120 gallons, etc. But I just can't find any actual code section that requires this. Can someone please point this out to me? Thanks!
One of our clients wants wall-mounted splits but I'm not comfortable specifying heat pumps only in our climate. I don't think anyone makes one but thought I'd check with y'all. Thanks.
Was just diagnosed with sleep apnea and they set my machine to provide 0.6 inches of water column. If I understand correctly, the extra pressure helps my throat expand a tiny bit more...and that's about all I know so far. I was just thinking that I could use a fan filter unit to pressurize the...
This is the first time anyone at our company has had to design mechanical and plumbing for a HUD project. Is there a good place to find all of the requirements we need to meet? Their website is a bit confusing and I'm having trouble getting in contact with someone over there. Thanks!
I'm the lead engineer at a small HVAC/Plumbing company and I was tasked to find a way to track engineering costs to help with future estimating. How do you typically estimate and track your costs? Is it just based on previous projects? One suggestion was that we track our costs on how much time...
I'm a little confused by the IMC as far as a split fan coil in the mechanical closets of apartments. The code clearly allows the closet to be used as a return air plenum but then all of the materials need to be plenum rated? I don't believe all of the components in the fan coil itself are plenum...
Anyone have a suggestion for this? These will be going in lobbies and controlling residential-style splits. The damper should be opened during business hours for outside air and closed otherwise. I know I can get a timer for this but I don't want it to be hidden or forgotten about so I'd feel...
Is there anything wrong with locating the dP sensor in a hydronic heating/cooling system at the very farthest fan coil in the system when all of the fan coils have PICV's? As I understand it , the 2/3 rule of thumb was to prevent the coils closest to the pumps from having too much flow but with...
Hello, HVAC & Plumbing engineer here. Anyone know if it's worth doing two backflow preventers in parallel (RP type)? We always do the pressure reducing valves in parallel (one large, one small, typically) to avoid "chattering" of the valve at low flows. I've never seen someone design two...
Has ASHRAE come out with any guidelines or standards design conditions that take global warming into account? I couldn't really find anything doing a search online but I'm thinking I need to start taking my load calcs up a couple of degrees at least to account for the annual record-breaking heat...
It's pretty common in my city that all of the apartment buildings are ventilated through the exhaust fans in the bathrooms, i.e., the bathrooms exhaust air continuously and fresh air is expected to come into the unit from the exterior wall and through cracks in the exterior windows. This is what...
I have a project for a commercial office building where they want to add a bunch of flush valve toilets and other plumbing fixtures without upsizing the pipe outside of the building. I have concluded that the 2" size will have issues with the added fixtures due to high velocities. Due to the...
