I installed an Espar radiant heat system on my last boat and loved it. I was all set to buy the equipment and begin the install on my new C42 when I got confused by the competing brands. Some are easy to elimnate due to size or other reasons, but the Webasto seems like a real contender. It has more btu's per dollar. It has been around for a long time, looks like good quality construction, etc. I am hoping that some of the experts here can help clear up my confusion on the relative merits. It is either the Espar D10WM or Webasto DBW2010. Any opinions out there?
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webasto
I've had webasto heaters on two boats. My 41 footer had one of the hydronic heaters. While I loved being able to shower on the hook with it, I found that it didn't remove enough humidity for our needs as liveaboards. For that reason, I put a webasto forced-air heater on the 46 footer. The boat is significantly dryer as a result. But if I'm on the hook for multiple days I have to run the engine to get hot water. Both systems perform well, and I give them high marks for reliability. The one thing I don't like is the amount of noise the fuel pump makes. It's a knocking sound that makes the aft cabin uninhabitable. Fortunately, we sleep forward. Otherwise, the forced air heater itself is significantly more quiet than the hydronic heater had been.
I've had webasto heaters on two boats. My 41 footer had one of the hydronic heaters. While I loved being able to shower on the hook with it, I found that it didn't remove enough humidity for our needs as liveaboards. For that reason, I put a webasto forced-air heater on the 46 footer. The boat is significantly dryer as a result. But if I'm on the hook for multiple days I have to run the engine to get hot water. Both systems perform well, and I give them high marks for reliability. The one thing I don't like is the amount of noise the fuel pump makes. It's a knocking sound that makes the aft cabin uninhabitable. Fortunately, we sleep forward. Otherwise, the forced air heater itself is significantly more quiet than the hydronic heater had been.
Hang the fuel pump....
John, Bob, et. al., I've had four Webasto furnaces in four different boats, one hydronic and the rest forced air. I prefer the forced air systems. I too use to be concerned about the clicking noise of the fuel pump. However, when I had the last Webasto furnace installed by Sure Marine in Seattle, their installer said removing the clicking sound was no problem. He hung the fuel pump on plastic wire ties. We really don't hear anything in the back stateroom when the furnace is on. One time after complaining about the noise of the exhaust when the furnace is on, Sure Marine experts said to just put a muffler on. We did and now the entire unit is very quiet. (Why they didn't tell me about this when I had it installed I do not know???) It is one of the nicest additions to our boat. It doesn't use much electricity and we have tapped into the main fuel tank. Around my harbor (Bellingham, WA) Webastos seem to outperform Espar but I have little data to support that statement. It may appear that way because of an aggressive dealer in the harbor. By the way, I've had this Webasto for nine years and have had no problems with it. It gets used about once a month during our rainy season which is fourteen months long. If I were to change anything I would put the thermostat control by the side of the bed. My wife and I tend to stay in bed until the other gets up to turn the furnace on. Being the one who has to use the head, I'm normally the one who does the cold deed. My best to you, Les
John, Bob, et. al., I've had four Webasto furnaces in four different boats, one hydronic and the rest forced air. I prefer the forced air systems. I too use to be concerned about the clicking noise of the fuel pump. However, when I had the last Webasto furnace installed by Sure Marine in Seattle, their installer said removing the clicking sound was no problem. He hung the fuel pump on plastic wire ties. We really don't hear anything in the back stateroom when the furnace is on. One time after complaining about the noise of the exhaust when the furnace is on, Sure Marine experts said to just put a muffler on. We did and now the entire unit is very quiet. (Why they didn't tell me about this when I had it installed I do not know???) It is one of the nicest additions to our boat. It doesn't use much electricity and we have tapped into the main fuel tank. Around my harbor (Bellingham, WA) Webastos seem to outperform Espar but I have little data to support that statement. It may appear that way because of an aggressive dealer in the harbor. By the way, I've had this Webasto for nine years and have had no problems with it. It gets used about once a month during our rainy season which is fourteen months long. If I were to change anything I would put the thermostat control by the side of the bed. My wife and I tend to stay in bed until the other gets up to turn the furnace on. Being the one who has to use the head, I'm normally the one who does the cold deed. My best to you, Les
Thanks John & Les
You are confirming my impressions about Websasto. I know from my previous experience in installing an Espar that there is much that can be done to quiet the system. Nobody told me about mufflers either, seems like a good idea though. I think you can mitigate the humitidy problem somewhat by bringing in exterior air to heat up. The low humidity air brought in from outside and heated up would have a lot of capacity to dry things out. It seemed to work well on my Espar and I was bringing in air from the unheated cockpit lockers. Thanks for your input. Bob V
You are confirming my impressions about Websasto. I know from my previous experience in installing an Espar that there is much that can be done to quiet the system. Nobody told me about mufflers either, seems like a good idea though. I think you can mitigate the humitidy problem somewhat by bringing in exterior air to heat up. The low humidity air brought in from outside and heated up would have a lot of capacity to dry things out. It seemed to work well on my Espar and I was bringing in air from the unheated cockpit lockers. Thanks for your input. Bob V
great idea, Les,...
...were it not raining at the moment, I'd be back there hanging it now. regarding humidity, the reason a forced air heater lowers humidity better is precisely because it brings outside air into the boat after drying it. A hydronic system, conversely, heats air already in the boat, moisture and all. Another advantage to the forced air systems is that they begin heating the boat significantly faster, because there's not all that water to heat up first. Both of these considerations are probably more important in day-to-day use than if you're just spending weekends on the boat.
...were it not raining at the moment, I'd be back there hanging it now. regarding humidity, the reason a forced air heater lowers humidity better is precisely because it brings outside air into the boat after drying it. A hydronic system, conversely, heats air already in the boat, moisture and all. Another advantage to the forced air systems is that they begin heating the boat significantly faster, because there's not all that water to heat up first. Both of these considerations are probably more important in day-to-day use than if you're just spending weekends on the boat.
humidity
Is there any reason that a hydronic system can not dry the boat as effectively as a forced-air if you bring air in from the exterior? On my C42 there is a clamshell type vent mounted on the transom that brings exterior air to the compressor for the refrig/freezer. This is not a tight connection the open end of the hose dead-ends about a foot in front of the fan on the compressor. I thought about adding another similar vent to the other side to feed the air intake for the furnace but that is too near where I plan to place the exhaust for the boiler. I would think with just one 3" hole into the large compartment would make it sufficently leaky to insure that you were drawing in air with low relative humidity compared to the interior. My main problem with the forced-air systems is the difficulty of finding room for all the big hose since I want a system that heats both heads, both staterooms, and the saloon with many small sources rather that a few big ones more centrally located. It is not much of a problem to find room for 3/4" hose. Also the heat loss as the water makes a round trip from stem to stern is very small. I would think that the air would loose a lot of heat energy on the way to the forward head from the aft lazzerette.
Is there any reason that a hydronic system can not dry the boat as effectively as a forced-air if you bring air in from the exterior? On my C42 there is a clamshell type vent mounted on the transom that brings exterior air to the compressor for the refrig/freezer. This is not a tight connection the open end of the hose dead-ends about a foot in front of the fan on the compressor. I thought about adding another similar vent to the other side to feed the air intake for the furnace but that is too near where I plan to place the exhaust for the boiler. I would think with just one 3" hole into the large compartment would make it sufficently leaky to insure that you were drawing in air with low relative humidity compared to the interior. My main problem with the forced-air systems is the difficulty of finding room for all the big hose since I want a system that heats both heads, both staterooms, and the saloon with many small sources rather that a few big ones more centrally located. It is not much of a problem to find room for 3/4" hose. Also the heat loss as the water makes a round trip from stem to stern is very small. I would think that the air would loose a lot of heat energy on the way to the forward head from the aft lazzerette.
Here's why
"...reason that a hydronic system can not dry the boat as effectively as a forced-air if you bring air in from the exterior..." Because in most installations the heating coils and fans of hydronic systems are "re"circulating air from behind seat and cushion supports, which come from where? - the closed up, open-to-the-bilge areas of the boat, plus, you are breathing and adding moisture to the space. There just isn't as mush fresh air being brought in, regardless of whether it's raining or not outside. Think of it this way: try your car heater, on a rainy day, on recycle, without using the defrost or air conditioning setting, and on recycle, not outside fresh air. What happens? Your windows fog up. The only cure is to have multiple speed and/or high speed fans with lots of heat in the water side. It is good to learn about these experiences.
"...reason that a hydronic system can not dry the boat as effectively as a forced-air if you bring air in from the exterior..." Because in most installations the heating coils and fans of hydronic systems are "re"circulating air from behind seat and cushion supports, which come from where? - the closed up, open-to-the-bilge areas of the boat, plus, you are breathing and adding moisture to the space. There just isn't as mush fresh air being brought in, regardless of whether it's raining or not outside. Think of it this way: try your car heater, on a rainy day, on recycle, without using the defrost or air conditioning setting, and on recycle, not outside fresh air. What happens? Your windows fog up. The only cure is to have multiple speed and/or high speed fans with lots of heat in the water side. It is good to learn about these experiences.
Stu , You are forgetting a basic law of physics
when the surface temperature is lower than the dew point you get condensation. Inadequate ventilation is one of the causes but taking 50 degree 100 percent relative humidity air from outside and and trying to heat it enough for it to feel dry is impossible.
when the surface temperature is lower than the dew point you get condensation. Inadequate ventilation is one of the causes but taking 50 degree 100 percent relative humidity air from outside and and trying to heat it enough for it to feel dry is impossible.
Hi Bob, a better alternative is the...
Wallas. Many on this site will recommend it over the two you are considering. I installed our diesel unit two years ago and it works great. Quiet, efficient and effective. Check them out. Scan Marine in Seattle is the North American distributor. Terry http://kb.sailboatowners.com/brand?post=384
Wallas. Many on this site will recommend it over the two you are considering. I installed our diesel unit two years ago and it works great. Quiet, efficient and effective. Check them out. Scan Marine in Seattle is the North American distributor. Terry http://kb.sailboatowners.com/brand?post=384
Bob, if I lived where you live...
...I wouldn't consider a hydronic system for a minute. On my last boat I plumbed in a permanent dehumidifier, and even with that the boat wasn't as dry as the present boat is with the forced air system. Take it from someone who cooks and showers onboard daily, even when it rains for two weeks solid like these past two weeks: forced air is the best way to beat humidity. On the old boat, I'd declare a pasta moratorium every January "until further notice." Tonight, the admiral is boiling potatoes even though it's raining outside. Can't argue with that.
...I wouldn't consider a hydronic system for a minute. On my last boat I plumbed in a permanent dehumidifier, and even with that the boat wasn't as dry as the present boat is with the forced air system. Take it from someone who cooks and showers onboard daily, even when it rains for two weeks solid like these past two weeks: forced air is the best way to beat humidity. On the old boat, I'd declare a pasta moratorium every January "until further notice." Tonight, the admiral is boiling potatoes even though it's raining outside. Can't argue with that.
Air Exchange ...........................
........... is the only thing that will keep humidity down which I think has been stated repeatedly in this forum. One example mentioned was where 100% relative humidity (RH) outside air at 50 deg. F was being brought into the cabin space. Reference to a psychometric chart shows that if that air were brought into a cabin and warmed to 70 deg. F, the RH of that air would drop to 49% which would be most comfortable. I installed Espar hot air heat when I purchased our '99 h-310 and I must confess, I always though I should have installed hydronic heat to avoid the bulky hot air hoses that take up no end of space. However, we have had numerous dinner parties at the dock in the cold winter rain and the interior of the boat is warm and dry with no condensation on the windows. The interior hygrometer usually shows around 55 to 60% RH. Best regards, s/v Island Hunter
........... is the only thing that will keep humidity down which I think has been stated repeatedly in this forum. One example mentioned was where 100% relative humidity (RH) outside air at 50 deg. F was being brought into the cabin space. Reference to a psychometric chart shows that if that air were brought into a cabin and warmed to 70 deg. F, the RH of that air would drop to 49% which would be most comfortable. I installed Espar hot air heat when I purchased our '99 h-310 and I must confess, I always though I should have installed hydronic heat to avoid the bulky hot air hoses that take up no end of space. However, we have had numerous dinner parties at the dock in the cold winter rain and the interior of the boat is warm and dry with no condensation on the windows. The interior hygrometer usually shows around 55 to 60% RH. Best regards, s/v Island Hunter
Ross, Ralph nailed it
the psychometric chart is one we air conditioning types use to measure heat and moisture in air conditioning systems, and Ralph's right. It's a short (engineering-ese) way to say what I said earlier, and when warming air in these cases has nothing to do with dew point other than condensation on cold surfaces, which is another subject. If the temperatures outside were cold engough, and most likely well below 40 degrees with uninsulated fiberglass hulls, I agree surface condensation would be an issue even after the air was heated.
the psychometric chart is one we air conditioning types use to measure heat and moisture in air conditioning systems, and Ralph's right. It's a short (engineering-ese) way to say what I said earlier, and when warming air in these cases has nothing to do with dew point other than condensation on cold surfaces, which is another subject. If the temperatures outside were cold engough, and most likely well below 40 degrees with uninsulated fiberglass hulls, I agree surface condensation would be an issue even after the air was heated.
even more confused now
Thanks for all the great advice guys but I'm even more confused than before. I thought I just needed to pick the best brand of two hydronic systems. Now everyone is telling me that hot air systems are the answer. Forgive my ignorance, I may be a slow learner. I thought the main reason that hot air systems had a drying effect was that they brought in outside air and heated it thereby reducing it's relative humidity. That heated air would mix with the cabin air and draw moisture out of the cabin air. Most of the people that install radiant heat systems may not bother to bring in exterior air since it is so much easier to recirculate cabin air. I did bring in exterior (lazerette air) on my last system and I thought it seemed to dry the air pretty effectively. I do not think I gave it a very good test though because about six months after I finished the install my wife fell in love with the C42 and suggested we order a new on. Can't hardly argue with that suggestion now can I. We are not live-aboards though so I question the validity of my experience with the Espar system compared with those of you taking daily showers and cooking pasta. We do plan to spend a lot more time cruising year-round in the PNW so that will probably be a lot like being a live-aboard. Can someone explain to me why the hydronic system would not dry the air as effectively as hot-air systems if I take the trouble to bring in exterior air in ample quantities? Thanks, Bob V
Thanks for all the great advice guys but I'm even more confused than before. I thought I just needed to pick the best brand of two hydronic systems. Now everyone is telling me that hot air systems are the answer. Forgive my ignorance, I may be a slow learner. I thought the main reason that hot air systems had a drying effect was that they brought in outside air and heated it thereby reducing it's relative humidity. That heated air would mix with the cabin air and draw moisture out of the cabin air. Most of the people that install radiant heat systems may not bother to bring in exterior air since it is so much easier to recirculate cabin air. I did bring in exterior (lazerette air) on my last system and I thought it seemed to dry the air pretty effectively. I do not think I gave it a very good test though because about six months after I finished the install my wife fell in love with the C42 and suggested we order a new on. Can't hardly argue with that suggestion now can I. We are not live-aboards though so I question the validity of my experience with the Espar system compared with those of you taking daily showers and cooking pasta. We do plan to spend a lot more time cruising year-round in the PNW so that will probably be a lot like being a live-aboard. Can someone explain to me why the hydronic system would not dry the air as effectively as hot-air systems if I take the trouble to bring in exterior air in ample quantities? Thanks, Bob V
In most
In most FHA systems the "return duct" is taking air from the cabin, not the exterior, and running it over the heat exchanger (HX) which will dry it to a point but not 100%. Depending on the HX's surface temp, and other contributing factors, you can remove between 5-60%+/- of the humidity in the cabin area. On a boat a properly installed FHA system will create a slightly dryer environment than a comparable BTU for BTU hydronic system. On Espar or Webasto units "combustion air" is taken from the exterior but this "sealed combustion" set up is separate from the HX side of the system. Webasto's and Espar's don't take the air needed for the combustion from inside the boat but they do take HX air, for heating the boat, from inside the cabin just as a home air conditioning or FHA system takes "return air" from a large duct within the house... In the North East we refer to FHA home heating systems as "scorched air" and most "scorched air" systems need duct mounted humidifiers such as a Maid-O-Mist so you don;t wind up with nose bleeds all winter long. In a virtually uninsulated boat however this "scorch" factor is a benefit and the sq footage is so small that the comfort factor between a hydronic system and a "scorched air" system is barely noticeable. Most hydronic boat installations use whats commonly referred to as a "air handler", which is like a car radiator with a fan blowing across it's surface, to heat the boat. Most FHW systems are run at a design temp of between 140 degree to 180 degree water temp and this, even with an "air handler", is not enough temp to scorch the air as effectively as it is with a FHA system. I would NEVER own a house with a FHA system in Maine but I would install one on my boat in a heart beat..
In most FHA systems the "return duct" is taking air from the cabin, not the exterior, and running it over the heat exchanger (HX) which will dry it to a point but not 100%. Depending on the HX's surface temp, and other contributing factors, you can remove between 5-60%+/- of the humidity in the cabin area. On a boat a properly installed FHA system will create a slightly dryer environment than a comparable BTU for BTU hydronic system. On Espar or Webasto units "combustion air" is taken from the exterior but this "sealed combustion" set up is separate from the HX side of the system. Webasto's and Espar's don't take the air needed for the combustion from inside the boat but they do take HX air, for heating the boat, from inside the cabin just as a home air conditioning or FHA system takes "return air" from a large duct within the house... In the North East we refer to FHA home heating systems as "scorched air" and most "scorched air" systems need duct mounted humidifiers such as a Maid-O-Mist so you don;t wind up with nose bleeds all winter long. In a virtually uninsulated boat however this "scorch" factor is a benefit and the sq footage is so small that the comfort factor between a hydronic system and a "scorched air" system is barely noticeable. Most hydronic boat installations use whats commonly referred to as a "air handler", which is like a car radiator with a fan blowing across it's surface, to heat the boat. Most FHW systems are run at a design temp of between 140 degree to 180 degree water temp and this, even with an "air handler", is not enough temp to scorch the air as effectively as it is with a FHA system. I would NEVER own a house with a FHA system in Maine but I would install one on my boat in a heart beat..
My vote is for radiant heat
As a 10 year liveaboard in a cold rainy climate (Vancouver), I have used both systems and would definately go with a hydronic system over forced air. The secret to controlling humidity on a boat is ventilation. You can bring fresh air from outside to your fans in a hydronic system as well. A hydronic system offers a more even heat, zone control for different cabins, hot water at anchor, and more reliability. As for Espar vs Webasto - I have used both and would favour the Webasto but would also recommend the Hurricane system - built in Vancouver for the marine market. They are very reliable but more importantly -easy to troubleshoot and repair.
As a 10 year liveaboard in a cold rainy climate (Vancouver), I have used both systems and would definately go with a hydronic system over forced air. The secret to controlling humidity on a boat is ventilation. You can bring fresh air from outside to your fans in a hydronic system as well. A hydronic system offers a more even heat, zone control for different cabins, hot water at anchor, and more reliability. As for Espar vs Webasto - I have used both and would favour the Webasto but would also recommend the Hurricane system - built in Vancouver for the marine market. They are very reliable but more importantly -easy to troubleshoot and repair.
the tradeoff
advantages of hydronic systems: * easier installation * can convert engine heat into cabin heat when motoring (a nice feature when bashing up the coast on a foggy night. Indeed, a hydronic system actually helps cool the engine.) * hot water when at anchor * toasty floorboards advantages of forced-air systems * superior reduction of humidity * begins heating cabin more quickly on cold mornings (important for those of us who catch an early train. Sometimes I'd be ready to leave the boat by the time my hydronic system started warming up.) * significantly more quiet In my mind, hydronic systems are preferable for sailors who tend only to do weekends aboard during the winter months, and forced-air systems are preferable for year-round liveaboards who are crazy enough to shower and cook on board even when it's raining. Yes, Bob, I think the decision between hydronic and forced air is far more significant than between espar and webasto.
advantages of hydronic systems: * easier installation * can convert engine heat into cabin heat when motoring (a nice feature when bashing up the coast on a foggy night. Indeed, a hydronic system actually helps cool the engine.) * hot water when at anchor * toasty floorboards advantages of forced-air systems * superior reduction of humidity * begins heating cabin more quickly on cold mornings (important for those of us who catch an early train. Sometimes I'd be ready to leave the boat by the time my hydronic system started warming up.) * significantly more quiet In my mind, hydronic systems are preferable for sailors who tend only to do weekends aboard during the winter months, and forced-air systems are preferable for year-round liveaboards who are crazy enough to shower and cook on board even when it's raining. Yes, Bob, I think the decision between hydronic and forced air is far more significant than between espar and webasto.
Awesome input guys.
Thank you all for helping me with this difficult decision. There is not total agreement out there obviously. It may have more to do with the different ways we all use our boats rather than there being one right answer. My analysis of the information provided is that as a cruiser (not liveaboard), the hydronic system pros outweigh the cons. I think I can help to mitigate some of the cons by bringing in large quantites of exterior air to insure rapid air-exchange of the interior. I think Webasto is probably the superior deal based on btus per dollar, larger hose and a few other details. I will run all this by my professional consultant and see if he concurs. I do most of my own work on the boat but with this system I plan to meet with a pro for about an hour or two to discuss system design and installation, then I go home and do all installation and plumbing, etc. After all that is done and ready to connect to electrical breaker, I make one more visit to the pro who checks my work makes final connection to electrical and fires it off for a test run. Thanks again to all those who provided input. I am truly amazed at the range of experience available on this forum. Bob V s/v Lucy C 42 MkII #1003
Thank you all for helping me with this difficult decision. There is not total agreement out there obviously. It may have more to do with the different ways we all use our boats rather than there being one right answer. My analysis of the information provided is that as a cruiser (not liveaboard), the hydronic system pros outweigh the cons. I think I can help to mitigate some of the cons by bringing in large quantites of exterior air to insure rapid air-exchange of the interior. I think Webasto is probably the superior deal based on btus per dollar, larger hose and a few other details. I will run all this by my professional consultant and see if he concurs. I do most of my own work on the boat but with this system I plan to meet with a pro for about an hour or two to discuss system design and installation, then I go home and do all installation and plumbing, etc. After all that is done and ready to connect to electrical breaker, I make one more visit to the pro who checks my work makes final connection to electrical and fires it off for a test run. Thanks again to all those who provided input. I am truly amazed at the range of experience available on this forum. Bob V s/v Lucy C 42 MkII #1003
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