Joined on December 20, 2005
Last Post on June 8, 2007
@ June 8, 2007 8:18 AM in Free A/C?Window Shaker. For that few days, I think it will work fine for you if the load is that small. A 8-9,000 BTU unit will take the edge off. As you said, it is only 5-10 days. That is the cheapest $300 you could spend, IMHO. Don't hate the messenger :P
@ June 7, 2007 5:58 PM in vent condensationthat your condensate pan is overflowing back down your return duct. Don is right again, that is odd. Return air is, by definition, room temperature so if that is humid enough to condense, you have bigger problems! I would check the ductwork, drain pan, area below the air handler... I cannot believe the grille moisture is primarily condensing on the grille itself.
@ June 7, 2007 5:36 PM in Free A/C?obviously limits your load (really has little effect). Your biggest load then, is the outside air you are introducing. You have to cool it to below your tolerable space dew-point. This would be for most people, no higher than 58-60 degrees. Any time the dew-point is over 60F is considered "muggy" by most folks. Here is the kicker with what you are proposing: Without wringing out the air you are bringing in, but rather only cooling it "as much as you can", you will positively raise the RH in the space. Take outside air at design temperatures of say, 90F and 74 wet-bulb. That is about 48% RH believe it or not. You would have to cool that air down to 67 degrees to get it to even start dropping of moisture. It will be 100% RH at this point, to start. Then you have to continue sub-cooling it to 55 degrees to get the dew-point down. If you do not do that last part, the RH in your space will climb. This is because you are simultaneously reducing the space temperature which raises the RH by default. With water at 65F, you might, at best, cool that air down to room temperature (75F, ten degrees above your EWT depending on your coil number of rows). So you will only get a few drops on the surface of the coil but no real dehumidification. Chilled water which we use in commercial/institutional buildings has to be at least 45 degrees if not cooler to work well. We are replacing all of the piping in a 100,000 SF school because they used 48 degree CHW to save energy instead of the 42 degree RH required to dehumidify. The result? Climbing space RH and condensation on the pipe under the insulation. Rotted off in layers. Just an example.
@ June 7, 2007 5:22 PM in Check Valve On Condensate pumpcheck valve should be fine. Horizontal pattern, installed in horizontal, not vertical, before the rise. If installed in the vertical, back-flow will allow settling of debris on the seat.. a drain valve for the leg downstream of the check (at the base of the rise) is a good feature to install to drain and flush. The vertical soft-seated checks tend to have smaller openings where things can get caught (the cross arm into which the stem shaft and spring floats specifically). Crane, Walworth, Milwaukee, all good.
@ June 7, 2007 4:41 PM in Free A/C?It is exactly that, Ken. You have to have the temperature well enough below the dewpoint to wring out the moisture. BTU's are BTU's but for them to work there has to be a temperature difference. You will "cool" the air, sure. But it will not dehumidify. Think of it this way- you can flow your 3 GPM at a 15 degree delta-T as you suggest, but suppose that temperature range is 85 degrees rising to 100- still the same BTU's, right? But no cooling will take place suitable to you because of the temperature range. In your case, the temperature difference you are seeking is between the water temperature (average coil temperature you can generate) and the dew-point temperature of the air you are cooling, more specifically the dew-point of the space conditions you seek. Trivia: The reason that "55 degrees" is the rough default for air conditioning supply air is that the dewpoint of that air is the same or less than a space at 75 degrees and 50% RH. Lower is better. I hope that helps explain it better! Brad
@ June 7, 2007 3:14 PM in Not full flow Air Separatorfilter, strainer, etc. in a bypass configuration will work. It will just take longer to do a full job. Keep in mind: 1) You will need some main-line restriction to get nearly any flow through it. Hard to convince flow in a 3" pipe that going through a 2" device with a scrub-brush is going to be fun. 2) I suggest you pipe it across supply and return unless it is a condensing boiler. Otherwise assure a good bit of pressure difference in parallel with the device. 3) The presumption of using any device in a bypass arrangement is that the rate of contaminants being introduced (air for a separator, dirt for a strainer or filter) is less than the through-put of the device. In other words, don't expect to deaerate a system with ongoing leaks.
@ June 7, 2007 3:04 PM in Please define \"delta-t\"Yes, exactly on Delta-T. The old joke regarding the phone greeting at a urologists office: "Urology. Can you hold?" :)
@ June 7, 2007 8:43 AM in Please define \"delta-t\"Which is the difference in pressure between two measurement points. Delta-Pee also refers to urological issues associated with older males compared to when they were younger. Wait 'til you see the gauges used to measure that... :)
@ June 6, 2007 1:36 PM in Unwanted gravity circulationfollow the "lefty-loosey/righty-tighty" dictum. Some have RH turns to open them by depressing the closure spring. Going to the left releases the spring so that it can bear on the clapper. The "fully open" feature is geared to allow gravity flow in power outages. You may well have fully opened the flow checks. Have you tried going the other way? No, not like that. I mean turning the knurled knob all the way in the opposite direction. Remember Newton's Fourth Law: "Gravity Wins".
@ June 5, 2007 6:40 PM in Should we convert from steam to hot waterThe ideal is to down-size your radiators to your newly improved lower heat loss. No one ever seems too but they talk about it a lot! Understand that the boiler is sized to your connected radiation so if over-sized for an uninsulated house, you will be that much more over-sized as must be your boiler. That is the down-side of all this. It all depends. The advice to get you to replace with a Mod-Con HW boiler is worth looking at. Crunch the numbers including total cost to re-pipe, the works. If you can keep the radiators (clean them inside and out) you have an asset that mirrors the original architecture and can add value in lower water temperatures. Key is, it all depends. Just do not throw out the steam for the sake of HW being the only answer.
@ June 5, 2007 2:53 PM in Should we convert from steam to hot waterYo, Milne... Radiant is always possible especially in those small areas, using a heat exchanger or indirect as a buffer and the distribution. Not a problem, done all the time. I just cannot see a rip-out as a means of saving money absent some extraordinary circumstances. I still love you. Now, John- Long Island? Matt Mad Dog!!! (three exclamation points, please) Sweeney of Triple Crown P&H in Floral Park is tops, not to the exclusion of others. Matt wanted to know steam so installed his own house system from scratch.
@ June 5, 2007 12:35 PM in Free A/C?What I have offered so far is that you would use a semi-conventional means but using the trout stream as a condensing source. Florida Heat Pump (FHP as it is commonly known) has a wide variety of devices using all manner of medium. Air to air, water to air, air to water, water to water... The fluid you use (applied directly to any cooling coil, I mean) would have to be about ten degrees colder than your desired leaving air temperature. Thus most DX systems have a 40-45 degree saturated suction temperature and chilled water enters in that range also (with counter-flow). What I am hoping is that by using the trout stream as a condensing medium you can achieve a high efficiency on the CHW side or use the refrigerant produced efficiently also. The trout stream ought to be a lot more efficient than condenser water at 85-90 degrees or air temperatures at 95 degree rating points. If you *do* use the trout stream directly (as a chilled water source), then you may lose humidity control and cool without ever getting below space dew-point. This will shoot your RH positively into the "check into a motel" range. I would not want that for either of you (unless it is a special occasion of course!) I guess all of that Green Power bought by the CV including Quebec Hydro has not given the promised savings has it? At least you know your hands fit nicely around your ankles. :)
@ June 5, 2007 9:39 AM in vent condensationAll of those factors can contribute. One factor to expand upon is the "poor airflow". If the volume moving across your coil is too low (think: clogged filters,where is the cat...?) the air coming off the coil will be sub-cooled too far below the dewpoint of the ambient air. Instead of supplying 52-55 degree air you might be introducing 35 to 40 degree air. Thus the surface of your grille will be down there in temperature, like a cold glass of beer on a humid day. The low airflow prevents good turn-over to condition and dry the space. I would hazard a guess that this occurs mostly during start-up when you are trying to pull down the temperature from a warm set-up unoccupied temperature. Random Drive-By Thinking, Brad
@ June 5, 2007 9:28 AM in Free A/C?If you have 150 to 200 CFM of airflow available, you could absorb that much heat by cooling it from say, 75F down to 38F (150 CFM) or 47.3 F. (200 CFM). Of course this presumes that the air coming out of the HEX is 75 F. Assuming there is no latent transfer on the HEX, you might get, on a 90 degree day, about 8-10 degrees taken off, depending. Your 90/73 (DB/WB respectively) at 45% RH would come out at about 81/70.5 or 60% RH, no loss of humidity. The dewpoint of that air is about 66 degrees F. Enthalpy would be about 34.6 h. Remove 6000 BTUH sensible from that 150 CFM air stream and you would cool it to about 44.1F. Enthalpy would be about 17.8 h. To do that, your total heat required would be about 11,200 BTUH or roughly a ton. Practically a 0.50 sensible heat ratio. The really good news is, depending on how much you and The Lovely Jaye perspire, (or glow), your RH will settle in the low 40's, high 30% range. Why do I say 150 CFM? Some HRV's fall into that category and it does not seem too low versus coil freezing. Close but not quite.
@ June 4, 2007 6:49 PM in Let's move to Venezuala?I agree with Steve- Cheap gas is a huge price to pay for nearly complete loss of freedom. Besides, when you are a producer as they are (high sulfur by the way) and have control of even private industries, you can charge however little you want. The cost is pretty much an indicator of the standard of living.
@ June 4, 2007 5:28 PM in customersLooking out for your customers like that counts for a lot. I suppose some people are like that and do not learn from repeated mistakes. I for one can never figure them out. I suppose the best you could do is to run the numbers for them over a cup of coffee, saying, for this job we did, if you did "X" as we suggested, you would have saved "Y". Instead, you paid "Z" not to mention aggravation and down-time potential. They seem to see the price of everything but the value of nothing, as someone quite pithy once said... I sure hope that they appreciate you regardless.
@ June 4, 2007 4:49 PM in Warehouse heating questionI would say 60 degrees absent specific information otherwise. Even given that though, I would make sure that there is good coverage in any remote corners where fire protection lines and water lines in general are present. Even in a 60 degree space, small pockets in remote corners, the new partitioning or any spot with air leakage can get to freezing quickly in really cold weather.
@ June 4, 2007 4:04 PM in Should we convert from steam to hot waterinto improving the envelope and keep the steam. Unless everything is falling apart (I doubt it), there is a certain joy in steam. This from a hydronic (hot water heating) junkie. To convert for a perceived efficiency gain is hardly ever worth it. Too many systems have been tossed for great expense and no real gains. Much can be done to achieve individual zone control (TRV vent valves for example). If your radiators are too large, that is not the worst thing. Sure, it is darn nice to have them match their room's best new smaller heat loss but they hold heat so nicely and heat so rapidly... I say, make your steam system it's personal best! Assure yourself that the near-boiler piping is correct, your mains and radiators are properly vented, your piping insulated, your pressure controls set as low as possible, your pets spayed or neutered... all good things!
@ June 4, 2007 8:52 AM in Free A/C?Do you have a calculated heat gain figure? At least one place to start. The thing about any heat recovery ventilator in principle is that, if you use it to generate cooling for the space, you have to incur a loss in the process (exhausting air, throwing it away.) I tend to look at HRV's as a way to make the most of a necessary but parasitic loss, the need to exchange air in a very tight structure. Sure, you can cool this air post-recovery and get some benefit from it but then you are throwing it away. I would far prefer to see you have a properly sized system (meaning "tight" or slightly undersized) focussed on dehumidification. The HRV will still play a role in reducing the overall direct losses. However, being sensible-only, the cooling recovery effect is only partial. If you are limited to such a small amount of airflow, work it to death... sort of the Unico approach. Cool it to the high 30's/low 40's F. to dry it out. You can turn 150 or 200 CFM into 0.75 to 1.0 tons of useful cooling- and dry tons at that.
@ June 4, 2007 8:28 AM in Things I learned this year (SE)Suit up in bio-garb and take what you can. You at least have receipts with serial numbers, right? Once you have them back in your possession, I would love to see the case made for their return to the house... If you do not do that, someone else with no stake in it will, or worse, a bulldozer will show up and all will be off to a landfill. As Scott said, Steve, you are a stand-up guy. That no good deed goes unpunished should apply to you of all people is a travesty.
@ June 4, 2007 8:18 AM in Fitting into old steam pipesthe fittings are cast iron (as opposed to malleable iron), you can score them with a grinder and whack them with a hand sledge or something larger. They will crack. Scoring helps you control that cracking and may allow you to save the threads remaining on the pipe. Cast Iron fittings are different in appearance than malleable in that CI fittings have larger bosses (bands of material) into which the pipe is threaded. CI does not have as much tensile strength as MI so needs more material. If you have MI fittings you can beat them with a hammer until the cows come home. You will have sore muscles, scratched pipe and a lot of cows in your house. If that is the case, I recommend taking a Sawzall to the piping, then to the cows. Fire up that grille. You will be hungry.
@ June 4, 2007 7:53 AM in Modulating AND ondensing, high efficiencyThere is only one condensing boiler that I know of that does not modulate- The Monitor MZ. The best on the market IMHO is the Viessmann Vitodens 200. They now offer a "100" version with a slightly different burner and no internal circulator, to compete at a lower price point but with excellent materials and quality. Triangle Tube Prestige Solo would make an excellent second manufacturer choice. Buderus, Lochinvar Knight, several others are all commonly available. I am sure you will hear more specifics from others. There are many preferences. What is key is, who will install it and service it? The two go hand in hand. The installer, like near-boiler piping, is often as much a part of the boiler as the boiler itself.