If the machine is to be housed on a wooden floor you will need a mat beneath to reduce vibration and also noise. If space is tight, the hydraulic options are usually the smallest. It's also worth checking your floor can take the weight if you're going for one of the bigger, heavier models. For most, this shouldn't be a problem, if you have any doubts get a surveyor to check as it could be a very expensive mistake!
This type of machine provides a smooth action with little wear and tear to the mechanism, and the flywheel itself could help to keep you cool as you work out. It's worth noting that although water rowers aim for a realistic rowing feel, competitive rowers often use air rowers for land training. They tend to be less expensive than water-powered rowing machines, as well.
One of the most common brand of ergometers is Concept2. The company offers multiple types of models, including the Model D, Model E, and the dynamic rower. An updated Rowperfect brand of dynamic rowers, RP3, produces ergometers that more naturally mimic the feel and resistance of rowing in a shell on the water. It additionally, shows a dynamic force curve of power that provides the rower with detailed information about their stroke which they can use to improve technique and get stronger.
Outside of resistance type, we found the number-one arbiter of ride feel to be cord quality. Water ergometers tend to employ nylon cords, while air ergometers feature metal chains — a durability factor we anticipated would result in our favoring air. But while all three water rowers aced our expectation of smooth, high-tension strokes, perfecting the chain seems to be more difficult: Some tug with just a slight rumble, others feature bouncy, grinding chains that are incredibly loud, something akin to angry snoring. As for nylon, the best wind and unwind like elastic silk — no slack, no sound, no catching, just perfectly even tension throughout the stroke.